LMK01801BISQE/NOPB - Texas Instruments

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

LMK01801 Dual Clock Divider Buffer

Check for Samples: LMK01801

1 Device Summary

1.1 Features

12 • 6 Differential Outputs (or up to 12 as

• Pin Control Mode or MICROWIRE (SPI) LVCMOS)

• Input and Output Frequency Range 1 kHz to 3.1 • Divides Values of 1 to 1045 or 1 to 8,

GHz Even and Odd

• Separate Input for Clock Output Banks A & B. • Analog and Digital Delays

• 14 Differential Clock Outputs in Two Banks (A • 50% Duty Cycle on All Outputs for All Divides

& B) • Separate Synchronization of Bank A and B.

– Output Bank A • RMS Additive Jitter 50 fs at 800 MHz

• 8 Differential, Programmable Outputs (Up

to 8 as LVCMOS) – 50 fs RMS Additive Jitter (12 kHz to 20 MHz)

• Divider Values of 1 to 8, Even and Odd. • Industrial Temperature Range: -40 to 85 °C

– Output Bank B • 3.15 V to 3.45 V Operation

1.2 Target Applications

• High Performance Clock Distribution and Division

• Wireless Infrastructure

• Datacom and Telecom Clock Distribution

• Medical Imaging

• Test and Measurement

• Military / Aerospace

1.3 Description

The LMK01801 is a very low noise solution for clocking systems that require distribution and frequency

division of precision clocks.

The LMK01801 features extremely low residual noise, frequency division, digital and analog delay

adjustments, and fourteen (14) programmable differential outputs: LVPECL, LVDS and LVCMOS (2

outputs per differential output).

The LMK01801 features two independent inputs that can be driven differentially (LVDS, LVPECL) or in

single-ended mode (LVCMOS, RF Sinewave). The first input drives output Bank A consisting of eight (8)

outputs. The second input drives output Bank B consisting of six (6) outputs.

1Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2All trademarks are the property of their respective owners.

specifications per the terms of the Texas Instruments standard warranty. Production

processing does not necessarily include testing of all parameters.

Test/

CLKoutTYPE_0

EN_PIN_CTRL

SYNC1/

CLKoutTYPE_2

SYNC0/

CLKoutTYPE_1

CLKin0

CLKin0*

CLKout0

CLKout1

CLKout1*

CLKout13

CLKout13*

CLKout12

CLKout12*

Mux

CLKin1

CLKin1*

CLKuWire/

CLKoutDIV_1

DATAuWire/

CLKoutDIV_0

LEuWire/

CLKoutDIV_2

Control

Registers

PWire

Port

Analog

Delay

Divider

(1-1045)

Digital

Delay

CLKout2

CLKout2*

CLKout3

CLKout3*

CLKout4

CLKout4*

CLKout5

CLKout5*

CLKout6

CLKout6*

CLKout7

CLKout7*

Divider

(1-8)

Divider

(1-8)

Bank A Bank B

Device

Control

CLKout0*

LVDS/

LVPECL

LVDS/

LVPECL/

LVCMOS

LVDS/

LVPECL/

LVCMOS

LVDS/

LVPECL/

LVCMOS

LVDS/

LVPECL/

LVCMOS

LVDS/

LVPECL/

LVCMOS

LVDS/

LVPECL/

LVCMOS

LVDS/

LVPECL

Divider

(1-8)

CLKout11

CLKout11*

CLKout10

CLKout10*

CLKout9

CLKout9*

CLKout8

CLKout8*

Divider

(2-8)

Mux

Divider

(2-8)

Mux

CG1 Divider

CG2 Divider

CG4 Divider

CG3 Divider

CLKin0 Divider

CLKin1 Divider

Clock Distribution Path A

Clock Distribution Path B

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

1.4 Functional Block Diagram

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

1 Device Summary ........................................ 16.9 CLOCK OUTPUT SYNCHRONIZATION ........... 15

1.1 Features ............................................. 16.10 DEFAULT CLOCK OUTPUTS ..................... 15

1.2 Target Applications .................................. 17 Functional Description ............................... 16

1.3 Description ........................................... 17.1 PROGRAMMABLE MODE ......................... 16

1.4 Functional Block Diagram ........................... 27.2 PIN CONTROL MODE ............................. 16

2 Device Information ...................................... 47.3 INPUTS / OUTPUTS ............................... 16

2.1 Functional Configurations ............................ 47.4 INPUT AND OUTPUT DIVIDERS .................. 16

2.2 Connection Diagram ................................. 57.5 FIXED DIGITAL DELAY ............................ 16

3 Electrical Specifications ............................... 77.6 CLOCK OUTPUT SYNCHRONIZATION (SYNC) .. 18

3.1 Absolute Maximum Ratings .......................... 78 General Programming Information ................ 26

3.2 Package Thermal Resistance ....................... 78.1 RECOMMENDED PROGRAMMING SEQUENCE .26

3.3 Recommended Operating Conditions ............... 78.2 REGISTER MAP ................................... 27

8.3 DEFAULT DEVICE REGISTER SETTINGS AFTER

3.4 Electrical Characteristics ............................ 8POWER ON/RESET ............................... 28

3.5 Serial MICROWIRE Timing Diagram ............... 11 8.4 REGISTER R0 ...................................... 29

4 Typical Performance Characteristics ............. 12 8.5 REGISTER R1 AND R2 ............................ 31

5 Measurement Definitions ............................ 13 8.6 REGISTER R3 ...................................... 33

5.1 DIFFERENTIAL VOLTAGE MEASUREMENT

TERMINOLOGY .................................... 13 8.7 REGISTER R4 ...................................... 35

6 Features ................................................. 14 8.8 REGISTER R5 ...................................... 36

6.1 SYSTEM ARCHITECTURE ........................ 14 8.9 REGISTER 15 ...................................... 37

6.2 HIGH SPEED CLOCK INPUTS (CLKin0/CLKin0* 9 Application Information .............................. 38

and CLKin1/CLKin1*) ............................... 14 9.1 POWER SUPPLY .................................. 38

6.3 CLOCK DISTRIBUTION ............................ 14 9.2 PIN CONNECTION RECOMMENDATIONS ....... 40

6.4 SMALL DIVIDER (1 to 8) ........................... 14 9.3 THERMAL MANAGEMENT ........................ 40

6.5 LARGE DIVIDER (1 to 1045 ) ...................... 14 9.4 DRIVING CLKin INPUTS ........................... 41

6.6 CLKout ANALOG DELAY .......................... 14 9.5 TERMINATION AND USE OF CLOCK OUTPUT

6.7 CLKout12 & CLKout13 DIGITAL DELAY .......... 15 (DRIVERS) ......................................... 42

6.8 PROGRAMMABLE OUTPUTS ..................... 15 Revision History ............................................ 46

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

2 Device Information

2.1 Functional Configurations

Table 2-1. Clock Output Configurations

Output Outputs in

Bank Input Clock Group CLKoutX/CLK Output Type Divider Ratios Delay

Divider Group

outX*

CG1 0 to 3 LVDS/LVPECL 0 to 3 1 to 8 No

CLKin0/CLKin0

ALVDS/LVPECL/

*CG2 4 to 7 4 to 7 1 to 8 No

LVCMOS

LVDS/LVPECL/

CG3 8 to 11 8 to 11 1 to 8 No

LVCMOS

CLKin1/CLKin1

BDigital and

*LVDS/LVPECL/ 1 to 1045

CG4 12 and 13 12 and 13 Analog

LVCMOS (1) (2)

(1) Digital Delay will not work if CLKout12_13_DIV = 1.

(2) See Section 3.4

Table 2-2. Pin Control Mode for EN_PIN_CTRL = Low

Pin Output Groups Pin=Low Pin=Middle Pin=High

CLKoutTYPE_0 CLKout0 to CLKout3 LVDS Powerdown LVPECL

CLKoutTYPE_1 CLKout4 to CLKout7 LVDS LVCOMS (Norm/Inv) LVPECL

CLKoutTYPE_2 CLKout8 to CLKout13 LVDS LVCMOS (Norm/Inv) LVPECL

CLKout0 to

CLKoutDIV_0 ÷ 1 ÷ 4 ÷ 2

CLKout3 Divider

CLKout4 to

CLKoutDIV_1 ÷ 1 ÷ 4 ÷ 2

CLKout7 Divider

CLKout8 to ÷ 1 ÷ 4 ÷ 2

CLKout11 Divider

CLKoutDIV_2 CLKout12 to ÷ 8 ÷ 512 ÷ 16

CLKout13 Divider

Table 2-3. Pin Control Mode for EN_PIN_CTRL = High(1)(2)

Pin Output Groups Pin=Low Pin=Middle Pin=High

CLKout0 to CLKout3 LVPECL

CLKoutTYPE_0 LVDS LVPECL

CLKout4 to CLkout7 LVCMOS (Norm/Inv)

CLKoutTYPE_1 CLKout8 to CLKout11 LVDS LVCMOS (Norm/Inv) LVPECL

CLKoutTYPE_2 CLKout12 to CLKout13 LVDS LVCMOS (Norm/Inv) LVPECL

CLKout0 to

CLKoutDIV_0 ÷ 1 ÷ 4 ÷ 2

CLKout7 Dividers

CLKout8 to

CLKoutDIV_1 ÷ 1 ÷ 4 ÷ 2

CLKout11 Divider

CLKout12 to

CLKoutDIV_2 ÷ 4 ÷ 512 ÷ 16

CLKout13 Divider

(1) Digital Delay will not work if CLKout12_13_DIV = 1.

(2) See Section 3.4

Submit Documentation Feedback

Product Folder Links: LMK01801

4748 46 45 44 43 42 41 40 39 38 37

1413 15 16 17 18 19 20 21 22 23 24

LEuWire/

CLKoutDIV_2

CLKout0

CLKout0*

CLKout2*

CLKin0

CLKout4

CLKout5

CLKout6*

Bias

CLKout9*

CLKout9

CLKout10

Vcc6_CLKin1

SYNC1/

CLKoutTYPE_2

CLKout12*

Vcc8_DIG

CLKout1*

CLKout1

Vcc1_CLKout

0_1_2_3

CLKout2

CLKout3*

CLKout3

Test/

CLKoutTYPE_0

SYNC0/

CLKoutTYPE_1

CLKin0*

Vcc2_CLKin0

CLKout4*

CLKout5*

Vcc3_CLKout

4_5_6_7

CLKout6

CLKout7*

CLKout7

Vcc4_Bias

EN_PIN_CTRL

CLKout8

CLKout8*

Vcc5_CLKout

8_9_10_11

CLKout10*

CLKout11*

CLKout11

CLKin1

CLKin1*

Vcc7_CLKout

12/13

CLKout12

CLKout13*

CLKout13

DATAuWire/

CLKoutDIV_0

CLKuWire/

CLKoutDIV_1

DAP

LLP-48

Top Down View

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

2.2 Connection Diagram

Figure 2-1. 48-Pin Package

Table 2-4. Pin Descriptions(1)

Pin Number Name(s) I/O Type Description

LEuWire/ MICROWIRE Latch Enable Input /

1 I CMOS / 3-State

CLKoutDIV_2 Pin control mode: clock divider 2

CLKout0

2, 3 O Programmable Clock output 0: LVDS or LVPECL

CLKout0*

CLKout1

4, 5 O Programmable Clock output 1: LVDS or LVPECL

CLKout1*

Vcc1_CLKout

6 I PWR Power supply for clock outputs 0, 1, 2, and 3

0_1_2_3

CLKout2,

7, 8 O Programmable Clock output 2: LVDS or LVPECL

CLKout2*

CLKout3,

9. 10 O Programmable Clock output 3: LVDS or LVPECL

CLKout3*

Test/ Reserved Test Pin /

11 I CMOS / 3-State

CLKoutTYPE_0 Pin control mode: clock output type select 0

SYNC0/

12 I CMOS / 3-State SYNC0 / Pin control mode: clock output type select 1

CLKoutTYPE_1

CLKin0/ Clock input 0. Supports clocking types including but not

13, 14 I ANLG

CLKin0* limited to LVDS, LVPECL, and LVCMOS

15 Vcc2_CLKin0 I PWR Power supply for clock input 0

(1) See Application Information section Section 9.2 for recommended connections.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

Table 2-4. Pin Descriptions(1) (continued)

Pin Number Name(s) I/O Type Description

CLKout4/

16, 17 O Programmable Clock output 4: LVDS, LVPECL, or LVCMOS

CLKout4*

CLKout5*/

18, 19 O Programmable Clock output 5: LVDS, LVPECL, or LVCMOS

CLKout5

Vcc3_CLKout

20 I PWR Power supply for clock outputs 4, 5, 6, and 7

4_5_6_7

CLKout6/

21, 22 O Programmable Clock output 6: LVDS, LVPECL, or LVCMOS

CLKout6*

CLKout7*/

23, 24 O Programmable Clock output 7: LVDS, LVPECL, or LVCMOS

CLKout7

25 Vcc4_Bias I PWR Power supply for Bias

26 Bias ANLG Bias bypass pin

27 EN_PIN_CTRL I 3-State Select MICROWIRE or pin control mode

CLKout8/

28, 29 O Programmable Clock output 8: LVDS, LVPECL, or LVCMOS

CLKout8*

CLKout9*/

30, 31 O Programmable Clock output 9: LVDS, LVPECL, or LVCMOS

CLKout9

Vcc5_CLKout

32 I PWR Power supply for clock outputs 8, 9, 10, and 11

8_9_10_11

CLKout10/

33, 34 O Programmable Clock output 10: LVDS, LVPECL, or LVCMOS

CLKout10*

CLKout11*/

35, 36 O Programmable Clock output 11: LVDS, LVPECL, or LVCMOS

CLKout11

37 Vcc6_CLKin1 I PWR Power supply for clock input 1

CLKin1/ Clock input 1. Supports clocking types including but not

38, 39 I ANLG

CLKin1* limited to LVDS, LVPECL, and LVCMOS

SYNC1/ SYNC pin for CLKin1 and bank B.

40 I CMOS / 3-State

CLKoutTYPE_2 Pin control mode: Clock output type select 2

Vcc7_CLKout

41 I PWR Power supply for clock outputs 12, and 13

12_13

CLKout12/

42, 43 O Programmable Clock output 12: LVDS, LVPECL, or LVCMOS

CLKout12*

CLKout13*/

44, 45 O Programmable Clock output 13: LVDS, LVPECL, or LVCMOS

CLKout13

46 Vcc8_DIG I PWR Power supply for digital

DATAuWire/ MICROWIRE DATA Pin / Pin control mode: Clock divider

47 I CMOS / 3-State

CLKoutDIV_0 0

CLKuWire/ MICROWIRE CLK Pin / Pin control mode: Clock divider

48 I CMOS / 3-State

CLKoutDIV_1 1

DAP DAP GND DIE ATTACH PAD, connect to GND

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam

during storage or handling to prevent electrostatic damage to the MOS gates.

3 Electrical Specifications

3.1 Absolute Maximum Ratings(1)(2)(3)(4)

Parameter Symbol Ratings Units

Supply Voltage (5) VCC -0.3 to 3.6 V

Input Voltage VIN -0.3 to (VCC + 0.3) V

Storage Temperature Range TSTG -65 to 150 °C

Lead Temperature (solder 4 seconds) TL+260 °C

Differential Input Current (CLKinX/X*) IIN ± 5 mA

Moisture Sensitivty Level MSL 3

(1) "Absolute Maximum Ratings" indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for

which the device is intended to be functional, but do not ensure specific performance limits. For ensured specifications and test

conditions, see the Electrical Characteristics. The ensured specifications apply only to the test conditions listed.

(2) This device is a high performance RF integrated circuit with an ESD rating up to 2.5 kV Human Body Model, up to 250 V Machine Model

and up to 1,250 V Charged Device Model and is ESD sensitive. Handling and assembly of this device should only be done at ESD-free

workstations.

(3) Stresses in excess of the absolute maximum ratings can cause permanent or latent damage to the device. These are absolute stress

ratings only. Functional operation of the device is only implied at these or any other conditions in excess of those given in the operation

sections of the data sheet. Exposure to absolute maximum ratings for extended periods can adversely affect device reliability.

(4) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and

specifications.

(5) Never to exceed 3.6 V.

3.2 Package Thermal Resistance

48-Lead WQFN Parameter Symbol Ratings Units

Thermal resistance from junction to ambient on 4- θJA 26 °C/W

layer JEDEC board (1)

Thermal resistance from junction to case θJC 3 °C/W

(2)

(1) Specification assumes 9 thermal vias connect the die attach pad to the embedded copper plane on the 4-layer JEDEC board. These

vias play a key role in improving the thermal performance of the WQFN. It is recommended that the maximum number of vias be used in

the board layout.

(2) Case is defined as the DAP (die attach pad).

3.3 Recommended Operating Conditions

Parameter Symbol Condition Min Typical Max Unit

Ambient TAVCC = 3.3 V -40 25 85 °C

Temperature

Supply Voltage VCC 3.15 3.3 3.45 V

Junction TJ125 °C

Temperature

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

3.4 Electrical Characteristics

(3.15 V ≤VCC ≤3.45 V, -40 °C ≤TA≤85 °C. Typical values represent most likely parametric norms at VCC = 3.3 V, TA= 25

°C, at the Recommended Operating Conditions at the time of product characterization and are not ensured.)

Symbol Parameter Conditions Min Typ Max Units

Current Consumption

ICC_PD Power Down Supply Current 1 mA

All clock delays disabled,

Supply Current with all clocks

ICC_CLKS CLKoutX_Y_DIV = 1, 313 390 mA

enabled (1) CLKoutX_TYPE = 1 (LVDS),

CLKin0/0* and CLKin1/1* Input Clock Specifications

CLKinX_MUX = Bypassed 0.001 3100 MHz

CLKoutX_Y_DIV = 1

CLKinX_MUX = Bypassed

fCLKinX Clock 0 or 1 Input Frequency .001 1600 MHz

CLKoutX_Y_DIV = 2 to 8

CLKin_MUX = Divide .001 3100 MHz

CLKinX_DIV = 1 to 8

SLEWCLKin Slew Rate on CLKin (2) 20% to 80% 0.15 0.5 V/ns

DUTYCLKin Clock input duty cycle 50 %

AC coupled to CLKinX; CLKinX* AC

coupled to Ground 0.25 2.4 Vpp

(CLKinX_BUF_TYPE = Bipolar

Clock Input,

VCLKin Single-ended Input Voltage AC coupled to CLKinX; CLKinX* AC

coupled to Ground 0.25 2.4 Vpp

(CLKinX_BUF_TYPE = MOS

VIDCLKin 0.25 1.55 |V|

AC coupled

(CLKinX_BUF_TYPE = Bipolar

VSSCLKin 0.5 3.1 Vpp

Clock Input

Differential Input Voltage (3) (4)

VIDCLKin 0.25 1.55 |V|

AC coupled

(CLKinX_BUF_TYPE = MOS

VSSCLKin 0.5 3.1 Vpp

DC offset voltage between 0 mV

Each pin AC coupled

VCLKinX-offset CLKinX/CLKinX* CLKinX_BUF_TYPE = Bipolar 0 mV

CLKinX* - CLKinX

VCLKin-VIH Maximum input voltage DC coupled to CLKinX; CLKinX* AC 2.0 VCC V

coupled to Ground

VCLKin-VIL Minimum input voltage 0.0 0.4 V

CLKinX_BUF_TYPE = MOS

DC offset voltage between Each pin AC coupled

VCLKinX-offset CLKinX/CLKinX* 55 mV

CLKinX_BUF_TYPE = MOS

CLKinX* - CLKinX

Digital Inputs (CLKuWire, DATAuWire, LEuWire) for EN_PIN_CTRL = MIDDLE

VIH High-Level Input Voltage 1.2 VCC V

VIL Low-Level Input Voltage 0.4 V

IIH High-Level Input Current VIH = VCC -5 5 µA

IIL Low-Level Input Current VIL = 0 -5 5 µA

Digital Inputs (SYNC0, SYNC1) for EN_PIN_CTRL = MIDDLE

VIH High-Level Input Voltage 1.2 VCC V

VIL Low-Level Input Voltage 0.4 V

High-Level Input Current

IIH VIH = VCC -5 5 µA

VIH = VCC

Low-Level Input Current

IIL VIL = 0 -40 -5 µA

VIL = 0 V

(1) For Icc for specific part configuration, see applications section Section 9.1.1 for calculating Icc.

(2) The minimum recommended slew rate for all input clocks is 0.5 V/ns. This is especially true for single-ended clocks. Phase noise

performance will begin to degrade as the clock input slew rate is reduced. However, the device will function at slew rates down to the

minimum listed. When compared to single-ended clocks, differential clocks (LVDS, LVPECL) will be less susceptible to degradation in

phase noise performance at lower slew rates due to their common mode noise rejection. However, it is also recommended to use the

highest possible slew rate for differential clocks to achieve optimal phase noise performance at the device outputs.

(3) See applications section Section 5.1 for definition of VID and VOD voltages.

(4) Refer to application note AN-912 Common Data Transmission Parameters and their Definitions (SNLA036) for more information.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

Electrical Characteristics (continued)

(3.15 V ≤VCC ≤3.45 V, -40 °C ≤TA≤85 °C. Typical values represent most likely parametric norms at VCC = 3.3 V, TA= 25

°C, at the Recommended Operating Conditions at the time of product characterization and are not ensured.)

Symbol Parameter Conditions Min Typ Max Units

Digital Inputs (CLKuWire, DATAuWire, LEuWire, SYNC0, SYNC1) for EN_PIN_CTRL= Low or High

VIH High-Level Input Voltage 2.6 VCC V

VIM Mid-Level Input Voltage 1.3 1.85 V

VIL Low-Level Input Voltage 0.7 V

IIH High-Level Input Current VIH = VCC 100 µA

IIM Mid-Level Input Current -10 10 µA

IIL Low-Level Input Current VIL= 0 -100 µA

Clock Skew and Delay

LVDS-to-LVDS, T = 25 °C,

FCLK = 800 MHz, RL= 100 Ω3

AC coupled, Within same Divider

CLKoutX to CLKoutY LVPECL-to-LVPECL, T = 25 °C

(5),(6) FCLK = 800 MHz, RL= 100 Ω

TSKEW 3 ps

emitter resistors = 240 Ωto GND

AC coupled, Within same Divider

Skew between any two LVCMOS RL= 50 Ω, CL= 10 pF,

outputs, same CLKout or different T = 25 °C, FCLK = 100 MHz, Within 50

CLKout (5),(6) same Divider

LVPECL to LVDS skew 32

MixedTSKEW Same device, T = 25 °C,

CLKoutX - LVDS to LVCMOS skew 830 ps

250 MHz, Within same Divider

CLKoutY LVCMOS to LVPECL skew 800

Maximum Analog

FADLY 1536 MHz

Delay Frequency

LVDS Clock Outputs (CLKoutX)

Maximum Clock Frequency

fCLKout RL= 100 Ω1600 MHz

(7) (8)

Differential Output Voltage

VOD (9) 225 400 575 mV

(10)

T = 25 °C, DC measurement

Change in Magnitude of VOD for

ΔVOD -50 50 mV

AC coupled to receiver input

complementary output states R = 100 Ωdifferential termination

VOS Output Offset Voltage 1.125 1.25 1.375 V

Change in VOS for complementary

ΔVOS 35 |mV|

output states

TROutput Rise Time 20% to 80%, RL= 100 Ω200 ps

TFOutput Fall Time 80% to 20%, RL= 100 Ω300 ps

ISA Output short circuit current - single Single-ended output shorted to -24 24 mA

ISB ended GND, T = 25 °C

Output short circuit current -

ISAB Complimentary outputs tied together -12 12 mA

differential

(5) Equal loading and identical clock output configuration on each clock output is required for specification to be valid. Specification not valid

for delay mode.

(6) Ensured by characterization.

(7) Ensured by characterization.

(8) Refer to typical performance charts for output operation performance at higher frequencies than the minimum maximum output

frequency.

(9) See applications section Section 5.1 for definition of VID and VOD voltages.

(10) Refer to application note AN-912 Common Data Transmission Parameters and their Definitions (SNLA036) for more information.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

Electrical Characteristics (continued)

(3.15 V ≤VCC ≤3.45 V, -40 °C ≤TA≤85 °C. Typical values represent most likely parametric norms at VCC = 3.3 V, TA= 25

°C, at the Recommended Operating Conditions at the time of product characterization and are not ensured.)

Symbol Parameter Conditions Min Typ Max Units

LVPECL Clock Outputs (CLKoutX)

20% to 80%, RL= 100 Ω,

TROutput Rise Time 200 ps

emitter resistors = 240 Ωto GND

80% to 20%, RL= 100 Ω,

TFOutput Fall Time 200 ps

emitter resistors = 240 Ωto GND

Low Common-Mode Voltage PECL (LCPECL)(1),(2)

Maximum Clock Frequency RL= 100 Ω,

fCLKout 3100 MHz

(3) (4) emitter resistors = 240 Ωto GND

VOH Output High Voltage 1.6 V

T = 25 °C, DC Measurement

VOL Output Low Voltage Termination = 50 Ωto 0.75 V

VCC - 0.6 V

VOD Output Voltage 535 840 1145 mV

1600 mV LVPECL (LVPECL) Clock Outputs (CLKoutX)

Maximum Clock Frequency RL= 100 Ω,

fCLKout 3100 MHz

(3) (4) emitter resistors = 240 Ωto GND

VOH Output High Voltage VCC - 0.94 V

T = 25 °C, DC Measurement

VOL Output Low Voltage Termination = 50 Ωto VCC - 1.9 V

VCC - 2.0 V

VOD Output Voltage 585 925 1240 mV

2000 mV LVPECL (2VPECL) Clock Outputs (CLKoutX)

Maximum Clock Frequency RL= 100 Ω,

fCLKout 3100 MHz

(3) (4) emitter resistors = 240 Ωto GND

VOH Output High Voltage VCC - 0.97 V

T = 25 °C, DC Measurement

VOL Output Low Voltage Termination = 50 Ωto VCC - 1.95 V

VCC - 2.3 V

VOD Output Voltage 705 1150 1585 mV

LVCMOS Clock Outputs (CLKoutX)

Maximum Clock Frequency

fCLKout 5 pF Load 250 MHz

(3) (4)

VOH Output High Voltage 1 mA Load VCC - 0.1 V

VOL Output Low Voltage 1 mA Load 0.1 V

IOH Output High Current (Source) VCC = 3.3 V, VO= 1.65 V 28 mA

IOL Output Low Current (Sink) VCC = 3.3 V, VO= 1.65 V 28 mA

Output Duty Cycle VCC/2 to VCC/2, FCLK = 100 MHz, T

DUTYCLK 45 50 55 %

(3) = 25 °C

20% to 80%, RL= 50 Ω,

TROutput Rise Time 400 ps

CL= 5 pF

80% to 20%, RL= 50 Ω,

TFOutput Fall Time 400 ps

CL= 5 pF

(1) For LCPECL, the common mode voltage is regulated (VOH=1.6V, VOL=VOH-Vsw, Vcm=(VOH+VOL)/2 ) and is more stable against

with PVT (process, supply, temperature) variations than conventional LVPECL implementations..

(2) With proper selection of external emitter resistors, LCPECL can also be used for DC-coupling with devices with low common voltage

such as 0.5V or 0,8V etc.

(3) Ensured by characterization.

(4) Refer to typical performance charts for output operation performance at higher frequencies than the minimum maximum output

frequency.

Submit Documentation Feedback

Product Folder Links: LMK01801

tDCS

D26 D25 D24 D23

tCDH tCWH tCWL

D22 D0 A4 A1 A0

MSB LSB

DATAuWire

CLKuWire

LEuWire

tCES

tEWH

tECS

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

Electrical Characteristics (continued)

(3.15 V ≤VCC ≤3.45 V, -40 °C ≤TA≤85 °C. Typical values represent most likely parametric norms at VCC = 3.3 V, TA= 25

°C, at the Recommended Operating Conditions at the time of product characterization and are not ensured.)

Symbol Parameter Conditions Min Typ Max Units

MICROWIRE Interface Timing

TECS LE to Clock Set Up Time See MICROWIRE Input Timing 25 ns

TDCS Data to Clock Set Up Time See MICROWIRE Input Timing 25 ns

TCDH Clock to Data Hold Time See MICROWIRE Input Timing 8 ns

TCWH Clock Pulse Width High See MICROWIRE Input Timing 25 ns

TCWL Clock Pulse Width Low See MICROWIRE Input Timing 25 ns

TCES Clock to LE Set Up Time See MICROWIRE Input Timing 25 ns

TEWH LE Pulse Width See MICROWIRE Input Timing 25 ns

TCR Falling Clock to Readback Time See MICROWIRE Readback Timing 25 ns

3.5 Serial MICROWIRE Timing Diagram

Figure 3-1. MICROWIRE Timing Diagram

edge of the CLKuWire signal. On the rising edge of the LEuWire signal, the register is sent from the shift

programming is complete the CLKuWire, DATAuWire, and LEuWire signals should be returned to a low

state.

Submit Documentation Feedback

Product Folder Links: LMK01801

10 100 1k 10k

-180

-175

-170

-165

-160

-155

-150

-145

-140

NOISE FLOOR (dBc/Hz)

FREQUENCY (MHz)

LVPECL (differential)

Re=240 

LVPECL (differential)

Re=120 

10 100 1k 10k

-180

-175

-170

-165

-160

-155

-150

-145

NOISE FLOOR (dBc/Hz)

FREQUENCY (MHz)

LVDS (differential)

LVCMOS

0 100 200 300 400 500

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

SINGLE ENDED P-P VOLTAGE (V)

FREQUENCY (MHz)

22 pF Load

10 pF Load

5 pF Load

0 50 100 150 200 250 300 350 400

ICC (mA)

FREQUENCY (MHz)

0 400 800 1200 1600 2000

0.0

0.2

0.4

0.6

0.8

1.0

DIFFERENTIAL P-P VOLTAGE (V)

FREQUENCY (MHz)

0 500 1000 1500 2000 2500 3000

0.0

0.5

1.0

1.5

2.0

DIFFERENTIAL P-P VOLTAGE (V)

FREQUENCY (MHz)

LVPECL 2V Mode

LVPECL 1.6V Mode

LCPECL Mode

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

4 Typical Performance Characteristics

Unless otherwise specified: Vdd=3.3V, TA=25 °C

See Section 5.1 for a description of VSS. See Section 5.1 for a description of VSS.

Figure 4-1. LVDS VSS vs. Frequency Figure 4-2. LVPECL VSS vs. Frequency

Figure 4-3. LVCMOS Vpp vs. Frequency Figure 4-4. Typical Dynamic ICC, CL= 5 pF

See Section 5.1 for a description of VSS.

Figure 4-5. LVPECL Noise Floor vs. Frequency Figure 4-6. LVDS & LVCMOS Noise Floor vs. Frequency

Submit Documentation Feedback

Product Folder Links: LMK01801

GND

VOD = | VA - VB | VSS = 2·VOD

VOD Definition VSS Definition for Output

Non-Inverting Clock

Inverting Clock

VOD 2·VOD

GND

VID = | VA - VB | VSS = 2·VID

VID Definition VSS Definition for Input

Non-Inverting Clock

Inverting Clock

VID 2·VID

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

5 Measurement Definitions

5.1 DIFFERENTIAL VOLTAGE MEASUREMENT TERMINOLOGY

The differential voltage of a differential signal can be described by two different definitions causing

confusion when reading datasheets or communicating with other engineers. This section will address the

measurement and description of a differential signal so that the reader will be able to understand and

discern between the two different definitions when used.

The first definition used to describe a differential signal is the absolute value of the voltage potential

between the inverting and non-inverting signal. The symbol for this first measurement is typically VID or

VOD depending on if an input or output voltage is being described.

The second definition used to describe a differential signal is to measure the potential of the non-inverting

signal with respect to the inverting signal. The symbol for this second measurement is VSS and is a

calculated parameter. Nowhere in the IC does this signal exist with respect to ground, it only exists in

reference to its differential pair. VSS can be measured directly by oscilloscopes with floating references,

otherwise this value can be calculated as twice the value of VOD as described in the first section

Figure 5-1 illustrates the two different definitions side-by-side for inputs and Figure 5-2 illustrates the two

different definitions side-by-side for outputs. The VID and VOD definitions show VAand VBDC levels that

the non-inverting and inverting signals toggle between with respect to ground. VSS input and output

definitions show that if the inverting signal is considered the voltage potential reference, the non-inverting

signal voltage potential is now increasing and decreasing above and below the non-inverting reference.

Thus the peak-to-peak voltage of the differential signal can be measured.

VID and VOD are often defined in volts (V) and VSS is often defined as volts peak-to-peak (VPP).

Figure 5-1. Two Different Definitions for

Differential Input Signals

Figure 5-2. Two Different Definitions for

Differential Output Signals

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

6 Features

6.1 SYSTEM ARCHITECTURE

The LMK01801 is a dual clock buffer which allows separate clock domains on the same IC with options to

divide and delay signals.

The LMK01801 consists of two separate buffer banks, each with its own input divider, output dividers and

programmable control of clock output channels.

• Bank A has two clock output groups, see the Section 2.1 for more details.

• Bank B has two clock output groups, one of which has analog and digital delay. See the Section 2.1 for

more details.

Each bank has it own common input divider and is then divided into output groups which share an output

divider.

The LMK01801 comes in a 48-pin WQFN package.

6.2 HIGH SPEED CLOCK INPUTS (CLKin0/CLKin0* and CLKin1/CLKin1*)

The LMK01801 has two clock inputs, CLKin0 and CLKin1 which can be driven differentially or single-

ended. See Section 9.4 for more information. Each input has a 2 to 8 divider that may be enabled or

bypassed.

6.3 CLOCK DISTRIBUTION

The LMK01801 features a total of 14 differential outputs. CLKout0 through CLKout7 are driven from

CLKin0 and CLKout8 through CLKout13 are driven from CLKin1.

6.4 SMALL DIVIDER (1 to 8)

There are three small dividers which drive CLKout0 to CLKout3, CLKout4 to CLKout7, and CLKout8 to

CLKout 11. These dividers support a divide range of 1 to 8 (even and odd).

6.5 LARGE DIVIDER (1 to 1045 )

The divider for CLKout12 and CLKout13 supports a divide range of 1 to 1045 (even and odd). When

divides of 26 or greater are used, the divider/delay block uses extended mode.

6.6 CLKout ANALOG DELAY

Clock outputs 12 and 13 include a fine (analog) delay for phase adjustment of the clock outputs.

The fine (analog) delay allows a nominal 25 ps step size and range from 0 to 475 ps of total delay.

Enabling the analog delay adds a nominal 500 ps of delay in addition to the programmed value.

When adjusting analog delay, glitches may occur on the clock outputs being adjusted.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

6.7 CLKout12 & CLKout13 DIGITAL DELAY

CLKout12 and CLKout13 includes a coarse (digital) delay for phase adjustment of the clock outputs.

The coarse (digital) delay allows a group of outputs to be delayed by 4.5 to 12 clock distribution path

cycles in normal mode, or from 12.5 to 522 clock cycles in extended mode. The delay step can be as

small as half the period of the clock distribution path by using the CLKout12_13_HS bit. e.g. 2 GHz clock

frequency without using CLKin1 input clock divider results in 250 ps coarse tuning steps.

The coarse (digital) delay value takes effect on the clock outputs after a SYNC event.

There are 2 different ways to use the digital (coarse) delay.

1. Fixed Digital Delay

2. Relative Dynamic Digital Delay

These are further discussed in the Functional Description.

6.8 PROGRAMMABLE OUTPUTS

The outputs of the LMK01801 are programmable in a combination of output types based on Table 2-1.

Programming the outputs is by MICROWIRE or by pin control mode based on the state of EN_PIN_CTRL

pin.

Any LVPECL output type can be programmed to LCPECL, 1600, or 2000 mVpp amplitude levels. The

2000 mVpp LVPECL output type is a Texas Instruments proprietary configuration that produces a 2000

mVpp differential swing for compatibility with many data converters and is also known as 2VPECL.

6.9 CLOCK OUTPUT SYNCHRONIZATION

Using the SYNC input causes all active clock outputs to share a rising edge. See Section 7.6 for more

information.

The SYNC event also causes the digital delay value to take effect.

6.10 DEFAULT CLOCK OUTPUTS

The power on reset sets the device to operate with all outputs active in bypass mode (no divide) with

LVDS output type. In this way the device can be used without programming for fan-out purposes.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

7 Functional Description

7.1 PROGRAMMABLE MODE

When the EN_PIN_CTRL pin is floating (default by internal pull-up/pull-down) then programming is via

MICROWIRE.

See Table 2-1 for a description of available programming options for the LMK01801 in programmable

mode.

7.2 PIN CONTROL MODE

The LMK01801 provides for an alternate function of the MICROWIRE (uWire) pins. This pin control mode

is set by the logic of the EN_PIN_CTRL pin to provide limited control of the outputs and dividers.

When the EN_PIN_CTRL pin is set high or low (not open) then the output states can be programmed by

pins, eliminating the need for an external FPGA or CPU.

If EN_PIN_CTRL is LOW then Table 2-2 in Section 2.1 defines how the outputs and dividers are

configured.

If EN_PIN_CTRL is HIGH then Table 2-3 in Section 2.1 defines how the outputs and dividers are

configured.

7.3 INPUTS / OUTPUTS

7.3.1 CLKin0 and CLKin1

There are two clock inputs CLKin0 and CLKin1. CLKin0 provides the input for output Bank A and CLKin1

provides the input for the output Bank B. Each input has it's own divider (2 to 8) that may be bypassed.

7.4 INPUT AND OUTPUT DIVIDERS

This section discusses the recommended usage of input and output dividers.

Clock inputs 0 and 1 each have an associated divider (2 to 8) that may be enabled or bypassed.

Clock groups 1, 2 and 3 have small output dividers (1 to 8). Clock group 4 (CLKout12 and CLKout13) has

a large output divider (1 to 1045).

While the input and output clock dividers may be used in any combination the recommended operating

frequency ranges are shown in the table below to minimize the phase noise floor:

Table 7-1. Input and Output Divider Input Frequency Ranges

Input Divider Output Divider Max Frequency

Bypassed Divide = 1 3.1 GHz

Bypassed Divide > 1 1.6 GHz

Divide = 2 to 8 Divide = 1 to 8 3.1 GHz

7.5 FIXED DIGITAL DELAY

This section discusses Fixed Digital Delay and associated registers.

Clock outputs 12 and 13 may be delayed relative to CLKout8 to CLKout 11 by up to 517.5 clock

distribution path periods if divide is 1 and 518.5 clock distribution path periods if divide is greater than 1.

By programming a digital delay value from 4.5 to 522 clock distribution path periods, a relative clock

output delay from 0 to 517.5 periods is achieved. The CLKout12_13_DDLY register sets the digital delay

as shown in the table Table 7-2.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

Table 7-2. Possible Digital Delay Values

CLKout12_13_DDLY CLKout12_13_HS Digital Delay

5 1 4.5

5 0 5

6 1 5.5

6 0 6

7 1 6.5

7 0 7

... ... ...

520 0 520

521 1 520.5

521 0 521

522 1 521.5

522 0 522

The CLKout12_13_DDLY value only takes effect during a SYNC event and if the

NO_SYNC_CLKout12_13 bit is cleared for this clock group. See Section 7.6 for more information.

The resolution of digital delay is related to the frequency at the input to the Clock Group 4 (CG4) clock

distribution path.

Digital Delay Resolution = 1 / (2 * Clock Frequency)

The digital delay between clock outputs can be dynamically adjusted with minimum or no disruption of the

output clocks. See Section 7.6.1 for more information.

7.5.1 Fixed Digital Delay - Example

Given a CLKin1 clock frequency of 983.04 MHz as input to CG4, by using digital delay the outputs can be

adjusted in 1 / (2 * 983.04 MHz) = ~509 ps steps (Assumes CLKin1_MUX = bypass).

To achieve a quadrature (90 degree) phase shift on 122.88 MHz outputs between CLKout12 and

CLKout11 from a clock frequency of 983.04 MHz program:

• Clock output divider to 8. CLKout8_11 = 8 and CLKout12_13_DIV = 8

• Set clock digital delay value. CLKout12_13_DDLY = 5, CLKout12_13_HS = 0.

The frequency of 122.88 MHz has a period of ~8.14 ns. To delay 90 degrees of a 122.88 MHz clock

period requires a ~2.03 ns delay. Given a digital delay step of ~509 ps, this requires a digital delay value

of 4 steps (2.03 ns / 509 ps = 4). Since the 4 steps are half period steps, CLKout12_13_DDLY is

programmed 2 full periods beyond 5 for a total of 7.

Table 7-3 shows some of the possible phase delays in degrees achievable in the above example.

Table 7-3. Relative phase shift from

CLKout12 and CLKout13 to CLKout8 to CLKout11

CLKout12_13_DDLY CLKout12_13_HS Relative Digital Delay Degrees of 122.88 MHz

5 1 -0.5 -23°

5 0 0.0 0°

6 1 0.5 23°

6 0 1.0 45°

7 1 1.5 68°

7 0 2.0 90°

8 1 2.5 113°

8 0 3.0 135°

9 1 3.5 158°

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

Table 7-3. Relative phase shift from

CLKout12 and CLKout13 to CLKout8 to CLKout11

(continued)

CLKout12_13_DDLY CLKout12_13_HS Relative Digital Delay Degrees of 122.88 MHz

9 0 4.0 180°

10 1 4.5 203°

10 0 5.0 225°

11 1 5.5 248°

11 0 6.0 270°

12 1 6.5 293°

12 0 7.0 315°

13 1 7.5 338°

13 0 8.0 360°

... ... ... ...

Figure 7-2 illustrates clock outputs programmed with different digital delay values during a SYNC event.

Refer to Section 7.6.1 for more information on dynamically adjusting digital delay.

7.6 CLOCK OUTPUT SYNCHRONIZATION (SYNC)

The purpose of the SYNC function is to synchronize the clock outputs with a fixed and known phase

relationship between each clock output selected for SYNC. SYNC can also be used to hold the outputs in

a low or 0 state. The NO_SYNC_CLKoutX_Y bits can be set to disable synchronization for a clock group.

The digital delay value set by CLKout12_13_DDLY takes effect only upon a SYNC event. The digital delay

due to CLKout12_13_HS takes effect immediately upon programming. See Section 7.6.1 for more

information on dynamically changing digital delay.

It is necessary to ensure that the CLKin1 signal is stable before a sync event occurs when

CLKout12_13_DIV is greater than 1.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

Effect of SYNC

When SYNC is asserted, the outputs to be synchronized are held in a logic low state. When SYNC is

unasserted, the clock outputs to be synchronized are activated and will transition to a high state

simultaneously with one another except where digital delay values have been programmed.

Refer to Section 7.6.1 for SYNC functionality when SYNC_QUAL = 1.

Table 7-4. Steady State Clock Output Condition

Given Specified Inputs

SYNC_POL SYNC Pin Clock Steady State

_INV

0 0 Active

0 1 Low

1 0 Low

1 1 Active

Methods of Generating SYNC

There are three methods to generate a SYNC event:

• Manual:

– Asserting the SYNC pin according to the polarity set by SYNC_POL_INV.

– Toggling the SYNC_POL_INV bit though MICROWIRE will cause a SYNC to be asserted.

• Automatic:

– Programming Register R4 when SYNC_EN_AUTO = 1 will generate a SYNC event for Bank B.

– Programming Register R5 when SYNC_EN_AUTO = 1 will generate a SYNC event for both Bank A

and Bank B.

Due to the high speed of the clock distribution path (as fast as ~322 ps period) and the slow slew rate of

the SYNC, the exact clock cycle at which the SYNC is asserted or unasserted by the SYNC is undefined.

The timing diagrams show a sharp transition of the SYNC to clarify functionality.

Avoiding clock output interruption due to SYNC

If a clock output has the NO_SYNC_CLKoutX_Y bits set they will be unaffected by the SYNC event. It is

possible to perform a SYNC operation with the NO_SYNC_CLKoutX_Y bit cleared, set the

NO_SYNC_CLKoutX_Y bits so that the selected clocks will not be affected by a future SYNC. Future

SYNC events will not effect these clocks but will still cause the newly synchronized clocks to be

resynchronized using the currently programmed digital delay values. When this happens, the phase

relationship between the first group of synchronized clocks and the second group of synchronized clocks

will be undefined. Except for CLKout12 and CLKout13 when synced using qualification mode. See

Section 7.6.1.

SYNC Timing

When discussing the timing of the SYNC function, one cycle refers to one period of the clock distribution

path.

Submit Documentation Feedback

Product Folder Links: LMK01801

5.5 cycles

4.5 cycles

CLKout0 to 11 ÷ 1

CLKout12 to 13 ÷ 2

5 cycles

CLKout12_13_DDLY

& CLKout12_13_HS

6 cycles

A B C D E F G

SYNC

CLKout12 to 13 ÷ 1

CLKout12_13_DDLY

& CLKout12_13_HS

CLKinX

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

CLKout8_11_DIV = 1

CLKout12_13_DIV = 2

The digital delay for clock outputs 12 and 13 is 5

The digital delay half step for all clock outputs is 0

SYNC1_QUAL = 0 (No qualification)

CLKout12_ADLY_SEL & CLKout13_ADLY_SEL is 0

Figure 7-1. Clock Output synchronization using the SYNC1 pin (SYNC1 is Active Low,

SYNC1_POL_INV=0)

Refer to Figure 7-1 during this discussion on the timing of SYNC. SYNC must be asserted for greater than

one clock cycle of the clock distribution path to register the SYNC event. After SYNC is asserted the

SYNC event will begin on the following rising edge of the distribution path clock, at time A. After this event

has been registered, the outputs will not reflect the low state for 4.5 cycles for CLKout0 - CLKout11 at time

B or 5.5 cycles for CLKout12 and CLKout 13 if divide = 1 or 6.5 cycles for CLKout12 and CLKout13 if

divide > 1, at time C. Due to the asynchronous nature of SYNC with respect to the output clocks, it is

possible that a runt pulse could be created when the clock output goes low from the SYNC event. This is

shown by CLKout12-13. See Section 7.6.1.2 for more information on synchronizing relative to an output

clock to eliminate or minimize this runt pulse for CLKout12 or CLKout13.

After SYNC becomes unasserted the event will be registered on the following rising edge of the

distribution path clock, time D. Clock outputs 0 through 11 will rise at time E, coincident with a rising

distribution clock edge that occurs after 5 cycles for CLKout0 to CLKout 11 and for CLKout12 to CLKout13

if CLKout12_13_DIV = 1. If CLKout12_13_DIV > 1 then the rising edge of CLKout12-CLKout13 will occur

after 6 cycles of the distribution path at time F plus as many more cycles as programmed by the digital

delay for that clock output path. The CLKout12 and CLKout13 will rise at time G, which is the Digital Delay

value plus 5 cycles when CLKout12_13_DIV = 1 or 6 cycles when CLKout12_13_DIV > 1.

See Figure 7-2 for further SYNC timing detail using different digital delays.

Submit Documentation Feedback

Product Folder Links: LMK01801

5.5 cycles

Case 1: CLKout12

CLKout12_13_DDLY &

CLKout12_13_HS

6 cycles

A B C D E F

SYNC

Case 2: CLKout12

Distribution

Path

4.5 cycles

Case 3: CLKout12

1 cycle

2.5 cycles

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

Case 1: CLKout12_13_DIV = 2, CLKout12_13_DDLY = 5

Case 2: CLKout12_13_DIV = 2, CLKout12_13_DDLY = 7

Case 3: CLKout12_13_DIV = 2, CLKout12_13_DDLY = 8

Case 1: CLKout12_13_HS = 1

Case 2: CLKout12_13_HS = 0

Case 3: CLKout12_13_HS = 0

SYNC1_QUAL = 0 (No qualification)

CLKout12_ADLY_SEL & CLKout13_ADLY_SEL is 0

Figure 7-2. Clock Output synchronization using the SYNC pin (SYNC is Active Low, SYNC_POL_INV=1)

Figure 7-2 illustrates the timing with various digital delays programmed.

• Time A) SYNC assertion event is registered.

• Time B) SYNC unassertion registered.

• Time C) All outputs toggle and remain low. A runt pulse can occur at this time as shown.

• Time D) After 6 + 4.5 = 10.5 cycles, in Case 1, CLKout12 rises.

• Time E) After 6 + 7 = 13 cycles, in Case 2, CLKout12 rises.

• Time F) After 6 + 8 = 14 cycles, Case 3, CLKout12 rises.

• Note: CLKout 12 and CLKout 13 are driven by the same divider and delay circuit, therefore, their timing

is always the same except when analog delay is used.

7.6.1 Dynamically Programming Digital Delay

To use dynamic digital delay synchronization qualification set SYNC1_QUAL = 3. This causes the

SYNC pulse to be qualified by a clock output so that the SYNC event occurs after a specified time from a

clock output transition. This allows the relative adjustment of clock output phase in real-time with no or

minimum interruption of clock outputs. Hence the term dynamic digital delay.

Note that changing the phase of a clock output requires momentarily altering in the rate of change of the

clock output phase and therefore by definition results in a frequency distortion of the signal.

Without qualifying the SYNC with an output clock, the newly synchronized clocks would have a random

and unknown digital delay (or phase) with respect to clock outputs not currently being synchronized. Only

CLKout12 can be used as a qualifying clock.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

Relative Dynamic Digital Delay

When the qualifying clock digital delay is being adjusted, because the qualifying clock and the adjusted

clock are the same, then a relative dynamic digital delay adjust is performed. Clocks with

NO_SYNC_CLKoutX_Y = 1 are defined as clocks not being adjusted. These clocks operate without

interruption.

SYNC and Minimum Step Size

The minimum step size adjustment for digital delay is half a clock distribution path cycle. This is achieved

by using the CLKout12_13_HS bit. The CLKout12_13_HS bit change effect is immediate without the need

for SYNC. To shift digital delay using CLKout12_13_DDLY, a SYNC signal must be generated for the

change to take effect.

Programming Overview

To dynamically adjust the digital delay with respect to an existing clock output the device should be

programmed as follows:

• Set SYNC1_QUAL = 3 for clock output qualification.

• Set NO_SYNC_CLKout12_13 = 0 to enable synchronization on CLKout12 and CLKout13.

• Set CLKout12_ADLY_SEL = 0.

• Set NO_SYNC_CLKoutX_Y = 1 for the output clocks, except CLKout12 and CLKout13, that will

continue to operate during the SYNC event. There is no interruption of output on these clocks.

• The SYNC_EN_AUTO bit may be set to cause a SYNC event to begin when register R4 is

programmed. The auto SYNC feature is a convenience since it does not require the application to

manually assert SYNC by toggling the SYNC_POL_INV bit or the SYNC pin when changing digital

delay.

Internal Dynamic Digital Delay Timing

Once SYNC is qualified by an output clock, 1.5 cycles later an internal one shot pulse will occur. The

width of the one shot pulse is 3 cycles. This internal one shot pulse will cause the outputs to turn off and

then back on with a fixed delay with respect to the falling edge of the qualification clock. This allows for

dynamic adjustments of digital delay with respect to an output clock.

The qualified SYNC timing is shown in Figure 7-3 for relative dynamic digital delay.

Dynamic Digital Delay Conditions

To perform a dynamic digital delay adjustment, the analog delay must be bypassed by setting

CLKout12_ADLY_SEL to 0. If the analog delay is not bypassed the output synchronization may be

inaccurate due to unknown analog delay settings.

When adjusting digital delay dynamically, the falling edge of the qualifying clock must coincide with the

falling edge of the clock distribution path. For this requirement to be met, program the CLKout12_13_HS

value of the qualifying clock group according to Table 7-5.

Table 7-5. Half Step programming requirement of

qualifying clock during SYNC event

CLKout12_13_DIV value CLKout12_13_HS

Odd Must = 1 during SYNC event.

Even Must = 0 during SYNC event.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

7.6.1.1 RELATIVE DYNAMIC DIGITAL DELAY

Relative dynamic digital delay can be used to program a clock output to a specific phase offset from

another clock output.

Pros:

• Direct phase adjustment with respect to same clock output.

• Possible glitch pulses from clock output will always be the same during digital delay adjustment

transient.

Cons:

• For some clock divide values there may be a glitch pulse due to SYNC assertion.

• Adjustments of digital delay requiring the half step bit (CLKout12_13_HS) for finer digital delay adjust

is complicated due to the half step requirement in Table 7-5 above.

7.6.1.2 RELATIVE DYNAMIC DIGITAL DELAY - EXAMPLE

To illustrate the relative dynamic digital delay adjust procedure, consider the following example.

System Requirements:

• CLKin1 Frequency = 983.04 MHz

• CLKout8 = 983.04 MHz (CLKout8_11_DIV = 1)

• CLKout12 = 491.52 MHz (CLKout12_13_DIV = 2)

• During initial programming:

– CLKout12_13_DDLY = 5

– CLKout12_13_HS = 0

– NO_SYNC_CLKoutX_Y = 0

The application requires the 491.52 MHz clock to be stepped in 90 degree steps (~508.6 ps), which is the

minimum step resolution allowable by the clock distribution path. That is 1 / 983.04 MHz / 2 = ~169.5 ps.

During the stepping of the 491.52 MHz clocks the 983.04 MHz clock must not be interrupted.

Step 1: The device is programmed from register R0 to R5 with values that result in the device operating

as desired, see the system requirements above. The phase of all the output clocks are aligned because all

the digital delay and half step values were the same when the SYNC was generated by programming

Step 2: Now the registers will be programmed to prepare for changing digital delay (or phase)

dynamically.

Use clock output for qualifying the SYNC pulse for dynamically

SYNC1_QUAL = 3 adjusting digital delay.

Clock output 8 (983.04 MHz) won't be affected by SYNC. It will

NO_SYNC_CLKout7_11 = 1 operate without interruption.

Automatically generation of SYNC is not allowed because of the half

step requirement.

SYNC1_AUTO = 0 (default) SYNC must be generated manually by toggling the SYNC_POL_INV

bit or the SYNC pin.

After the above registers have been programmed, the application may now dynamically adjust the digital

delay of the 491.52 MHz clocks.

Step 3: Adjust digital delay of CLKout12 by one step.

Refer to Table 7-6 for the programming sequence to step one half clock distribution period forward or

backwards.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

Table 7-6. Programming sequence for one step adjust

Step direction and current HS state Programming Sequence

Adjust clock output one step forward. 1. CLKout12_13_HS = 1.

CLKout12_13_HS = 0. 1. CLKout12_13_DDLY = 9.

Adjust clock output one step forward. 2. Perform SYNC event.

CLKout12_13_HS = 1. 3. CLKout12_13_HS = 0.

1. CLKout12_13_HS = 1.

Adjust clock output one step backward. 2. CLKout12_13_DDLY = 5.

CLKout12_13_HS = 0. 3. Perform SYNC event.

Adjust clock output one step backward. 1. CLKout12_13_HS = 0.

CLKout12_13_HS = 1.

To fulfill the qualifying clock output half step requirement in Table 7-5 when dynamically adjusting digital

delay, the CLKout12_13_HS bit must be set if CLKout12 or CLKout13 has an odd divide. So before any

dynamic digital delay adjustment, CLKout12_13_HS must be set because the clock divide value is odd. To

achieve the final required digital delay adjustment, the CLKout12_13_HS bit may cleared after SYNC.

If a SYNC is to be generated this can be done by toggling the SYNC pin or by toggling the

SYNC_POL_INV bit. Because of the internal one shot pulse, no strict timing of the SYNC pin or

SYNC_POL_INV bit is required. After the SYNC event, the clock output will be at the specified phase. See

Figure 7-3 for a detailed view of the timing diagram. The timing diagram critical points are:

• Time A) SYNC assertion event is registered.

• Time B) First qualifying falling clock output edge.

• Time C) Second qualifying falling clock output edge.

• Time D) Internal one shot pulse begins. 5.5 cycles later CLKout12 outputs will be forced low while 8.5

cycles later CLKout8 outputs will be forced low.

• Time E) Internal one shot pulse ends. 6 cycles + digital delay cycles later CLKout12 or CLKout13

outputs rise. 10 cycles later CLKout8 to CLKout11 outputs rise.

• Time F) CLKout12 to CLKout13 outputs are forced low.

• Time G) Beginning of digital delay cycles.

• Time H) CLKout8 to CLKout11 outputs are forced low.

• Time I) CLKout8 to CLKout11 outputs rise now.

• Time j) For CLKout12_13_DDLY = 5; the CLKout12 and CLKout13 outputs rise now.

Submit Documentation Feedback

Product Folder Links: LMK01801

1.5

cycles

CLKout8 to 11, ÷ 2

CLKout12 to 13, ÷ 2

HS = 1

CLKout12_13_DDLY &

CLKout12_13_HS

A B C D E

CLKin1

Internal One

Shot Pulse

3 cycles

H I

6 cycles

10.5 cycles

A B C D E F G J

6 cycles

8.5 cycles

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

(SYNC1_QUAL = 1, Qualify with clock output)

Starting condition is after half step is removed (CLKout12_13_HS = 0).

Figure 7-3. Relative Dynamic Digital Delay Programming Example, 2nd adjust

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

8 General Programming Information

LMK01801 devices are programmed using 32-bit registers. Each register consists of a 4-bit address field

and 23-bit data field. The address field is formed by bits 0 through 3 (LSBs) and the data field is formed by

bits 4 through 31 (MSBs). The contents of each register is clocked in MSB first (bit 31), and the LSB (bit 0)

last. During programming, the LE signal should be held LOW. The serial data is clocked in on the rising

edge of the CLK signal. After the LSB (bit 0) is clocked in the LE signal should be toggled LOW-to-HIGH-

to-LOW to latch the contents into the register selected in the address field. It is recommended to program

registers in numeric order, for example R0 to R5 and R15 to achieve proper device operation. Figure 3-1

illustrates the serial data timing sequence.

8.1 RECOMMENDED PROGRAMMING SEQUENCE

Registers are programmed in numeric order with R0 being the first and R15 being the last register

programmed. The recommended programming sequence involves programming R0 with the reset bit (b4)

set to 1 to ensure the device is in a default state. Then R0 is programmed again, the reset bit is be

cleared to 0 during the re-programming of R0.

8.1.1 Overview

• R0 (Init):

– Program R0 with RESET = 1. This ensures that the device is configured with default settings. When

RESET =1, all other R0 bits are ignored.

• R0: Powerdown Controls and CLKin Dividers

– Program R0 with RESET = 0

• R1 and R2: Clock output types

• R3: SYNC Features and Analog Delay for CLKout12 and CLKout13

• R4: Dynamic Digital Delay for CLKout12 and CLKout13

• R5: CLKout Dividers and Analog Delay Select

• R15: uWireLock

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

8.2 REGISTER MAP

Table 8-1 provides the register map for device programming:

Table 8-1. Register Map

Data [31:4] Address [3:0]

CLKin1_ CLKin0_

R0 0 10 0 10 0 0 CLKin1_DIV CLKin0_DIV 1 1 0000

MUX MUX

RESET

CLKout4_7_PD

CLKout0_3_PD

POWERDOWN

CLKout8_11_PD

CLKout12_13_PD

CLKin1_BUF_TYPE

CLKin0_BUF_TYPE

CLKout3_ CLKout2_ CLKout1_ CLKout0_

R1 CLKout7_TYPE CLKout6_TYPE CLKout5_TYPE CLKout4_TYPE 0 0 0 1

TYPE TYPE TYPE TYPE

R2 0 0 0 0 CLKout13_TYPE CLKout12_TYPE CLKout11_TYPE CLKout10_TYPE CLKout9_TYPE CLKout8_TYPE 0 0 1 0

SYNC1_

R3 00010 0 1 1 0 CLKout12_13_ADLY 0 0 1 1

QUAL

SYNC1_FAST

SYNC0_FAST

SYNC1_AUTO

SYNC0_AUTO

CLKout12_13_HS

SYNC1_POL_INV

SYNC0_POL_INV

NO_SYNC_CLKout4_7

NO_SYNC_CLKout0_3

NO_SYNC_CLKout8_11

NO_SYNC_CLKout12_13

R4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CLKout12_13_DDLY 0 1 0 0

CLKout8_11 CLKout4_7 CLKout0_3

R5 0 0 0 0 CLKout12_13_DIV 0 0 0 1 0 1

_DIV _DIV _DIV

CLKout13_ADLY_SEL

CLKout12_ADLY_SEL

R15 000000000000000000000101 1 1 1 1111

uWireLock

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

8.3 DEFAULT DEVICE REGISTER SETTINGS AFTER POWER ON/RESET

The Default Device Register Settings after Power On/Reset Table below illustrates the default register

settings programmed in silicon for the LMK018xx after power on or asserting the reset bit. Capital X and Y

represent numeric values.

Table 8-2. Default Device Register Settings after Power On/Reset

Default Bit Location

Field Name Value Default State Field Description Register (MSB:LSB)

(decimal)

RESET 0 Not in reset Performs power on reset for device R0 4

Disabled (device is

POWERDOWN 0 Device power down control R0 5

active) Power down the divider and clock outputs 0

CLKout0_3_PD 0 Disabled R0 6

through 3

Disabled Power down the divider and clock outputs 4

CLKout4_7_PD 0 R0 7

through 7

Disabled Power down the divider and clock outputs 8

CLKout8_11_PD 0 R0 8

through 11

Disabled Power down the divider and clock outputs 12

CLKout12_13_PD 0 R0 9

through 13

CLKin0_BUF_TYPE 0 Bipolar Clock in buffer type R0 10

CLKin1_BUF_TYPE 0 Bipolar Clock in buffer type R0 11

CLKin0_DIV 2 Divide by 2 Divider value for CLKin0 R0 14:16 [3]

CLKin0_MUX 0 Bypass Enables or bypasses the CLKin0 divider R0 17:18 [2]

CLKin1_DIV 2 Divide by 2 Divider value for CLKin1 R0 19:21 [3]

CLKin1_MUX 0 Bypass Enables or bypasses the CLKin1 divider R0 22:23 [2]

CLKout0_TYPE 1 LVDS R1 4:6 [3]

CLKout1_TYPE 1 LVDS R1 7:9 [3]

Individual clock output format. Select from

LVDS/LVPECL.

CLKout2_TYPE 1 LVDS R1 10:12 [3]

CLKout3_TYPE 1 LVDS R1 13:15 [3]

CLKout4_TYPE 1 LVDS R1 16:19 [4]

CLKout5_TYPE 1 LVDS R1 20:23 [4]

CLKout6_TYPE 1 LVDS R1 24:27 [4]

CLKout7_TYPE 1 LVDS R1 28:31 [4]

CLKout8_TYPE 1 LVDS R2 4:7 [4]

Individual clock output format. Select

from LVDS/LVPECL/LVCMOS.

CLKout9_TYPE 1 LVDS R2 8:11 [4]

CLKout10_TYPE 1 LVDS R2 12:15 [4]

CLKout11_TYPE 1 LVDS R2 16:19 [4]

CLKout12_TYPE 1 LVDS R2 20:23 [4]

CLKout13_TYPE 1 LVDS R2 24:27 [4]

No delay Analog delay setting for CLKout12 &

CLKout12_13_ADLY 0 R3 4:9 [6]

CLKout13.

CLKout12_13_HS 0 No Shift Half shift for digital delay. R3 10

Not Qualified Allows SYNC operations to be qualified by a

SYNC1_QUAL 0 R3 11:12 [2]

clock output

SYNC0_POL_INV 1 Logic Low R3 14

Sets the polarity of the SYNC pin when input

SYNC1_POL_INV 1 Logic Low R3 15

NO_SYNC_CLKout0_3 0 Will sync R3 16

NO_SYNC_CLKout4_7 0 Will sync R3 17

Disable individual clock groups from being

synchronized.

NO_SYNC_CLKout8_11 0 Will sync R3 18

NO_SYNC_CLKout12_13 0 Will sync R3 19

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

Table 8-2. Default Device Register Settings after Power On/Reset (continued)

Default Bit Location

Field Name Value Default State Field Description Register (MSB:LSB)

(decimal)

SYNC0_FAST 0 Disabled R3 23

Enables synchronization circuitry.

SYNC1_FAST 0 Disabled R3 24

Automatic SYNC is started by programming a Register

SYNC0_AUTO 1 R3 25

Automatic SYNC is started by programming a Register

SYNC1_AUTO 1 R3 26

R4 or R5

5 clock cycles Digital Delay setting for CLKout12 &

CLKout12_13_DDLY 5 R4 4:13 [10]

CLKout13.

CLKout0_3_DIV 1 Divide-by-1 R5 4:6 [3]

CLKout4_7_DIV 1 Divide-by-1 Divider for clock outputs. R5 7:9 [3]

CLKout8_11_DIV 1 Divide-by-1 R5 10:12 [3]

CLKout12_ADLY_SEL 0 No Delay Enable Digital Delay for CLKout12 R5 13

CLKout13_ADLY_SEL 0 No Delay Enable Digital Delay for CLKout 13 R5 14

CLKout12_13_DIV 1 Divide-by-1 Divider for clock output. R5 17:27 [11]

uWireLock 0 Writeable The values of registers R0 to R5 are lockable R15 4

8.4 REGISTER R0

The R0 register controls reset, global power down, the power down functions for the channel dividers and

their corresponding outputs, CLKinX divider value and CLKinX divide select. The X, Y in CLKoutX_Y_PD

denote the actually clock output which may be from 0 to 13 where X is the first CLKout and Y is the last

CLKout.

8.4.1 RESET

Setting this bit will cause the silicon default values to be set upon loading of R0 by a high LEuWire pin.

When programming register R0 with the RESET bit set, all other programmed values are ignored.

The RESET bit is automatically cleared upon writing any other register. For instance, when R0 is written to

again with default values.

If the user reprograms the R0, after the initial programming then set RESET = 0.

Table 8-3. RESET

R0[4] State

0 Normal operation

1 Reset (automatically cleared)

8.4.2 POWERDOWN

Setting this bit causes the device to enter powerdown mode. Normal operation is resumed by clearing this

bit with MICROWIRE. All other MICROWIRE settings are preserved during POWERDOWN.

Table 8-4. POWERDOWN

R1[5] State

0 Normal operation

1 Powerdown

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

8.4.3 CLKoutX_Y_PD

This bit powers down the clock outputs as specified by CLKoutX to CLKoutY. This includes the divider and

output buffers.

Table 8-5. CLKoutX_Y_PD Programming Addresses

CLKoutX_Y_PD Programming Address

CLKout0_3_PD R0[6]

CLKout4_7_PD R0[7]

CLKout8_11_PD R0[8]

CLKout12_13_PD R0[9]

Table 8-6. CLKoutX_Y_PD

R0[6,7,8,9] State

0 Power up clock group

1 Power down clock group

8.4.3.1 CLKinX_BUF_TYPE

There are two input buffer types for CLKin0 and CLKin1: bipolar or CMOS. Bipolar is recommended for

differential inputs such as LVDS and LVPECL. CMOS is recommended for DC coupled single ended

inputs.

When using bipolar, CLKinX and CLKinX* input pins must be AC coupled when using differential or single

ended input.

When using CMOS, CLKinX and CLKinX* input pins may be AC or DC coupled with a differential input.

When using CMOS in a single ended mode, the used clock input pin (CLKinX or CLKinX*) may be AC or

DC coupled to the signal source. The unused CLKin shouLd be AC coupled to ground.

The programming address table shows at what register the specified CLKinX_BUF_TYPE is located.

The CLKinX_BUF_TYPE table shows the programming definition for these registers.

Table 8-7. CLKinX_BUF_TYPE Programming Addresses

CLKinX_BUF_TYPE Programming Address

CLKin0_BUF_TYPE R0[10]

CLKin1_BUF_TYPE R0[11]

Table 8-8. CLKinX_BUF_TYPE

R0[10] CLKinX Buffer Type

0 Bipolar

1 CMOS

8.4.3.2 CLKinX_DIV

These set the CLKin divide value, from 2-8.

Table 8-9. CLKinX_DIV Programming Address

CLKinX_DIV Programming Address

CLKin0_DIV R0[16:14]

CLKin1_DIV R0[21:19]

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

Table 8-10. CLKinX_DIV

R0[21:19, 16:14] Divide Value

0 (0x00) 8

1 (0x01) 2

2 (0x02) 2

3 (0x03) 3

4 (0x04) 4

5 (0x05) 5

6 (0x06) 6

7 (0x07) 7

8.4.3.3 CLKinX_MUX

These bits select whether or not the CLKin divider is bypassed or enabled.

Table 8-11. CLKinX_MUX Programming Address

CLKinX_MUX Programming Address

CLKin0_MUX R0[18:17]

CLKin1_MUX R0[23:22]

Table 8-12. CLKinX_MUX

R0[23:22, 18:17] State

0 (0x00) Bypass

1(0x01) Divide

8.5 REGISTER R1 AND R2

Registers R1 and R2 set the clock output types.

8.5.1 CLKoutX_TYPE

The clock output types of the LMK01801 are individually programmable. The CLKoutX_TYPE registers set

the output type of an individual clock output to LVDS, LVPECL, LVCMOS, or powers down the output

buffer. Note that LVPECL supports three different amplitude levels and LVCMOS supports single

LVCMOS outputs, inverted, and normal polarity of each output pin for maximum flexibility.

The programming addresses table shows at what register and address the specified clock output

CLKoutX_TYPE register is located.

The CLKoutX_TYPE table shows the programming definition for these registers.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

Table 8-13. CLKoutX_TYPE Programming Addresses

CLKoutX Programming Address

CLKout0 R1[4:6]

CLKout1 R1[7:9]

CLKout2 R1[10:12]

CLKout3 R1[13:15]

CLKout4 R1[16:19]

CLKout5 R1[20:23]

CLKout6 R1[24:27]

CLKout7 R1[28:31]

CLKout8 R2[4:7]

CLKout9 R2[8:11]

CLKout10 R2[12:15]

CLKout11 R2[16:19]

CLKout12 R2[20:23]

CLKout13 R2[24:27]

Table 8-14. CLKoutX_TYPE, 4 bits

R1[31:28,27:24,23:20,19:16], Definition

R2[27:24,23:20,19:16,15:12,11:8,7:4]

0 (0x00) Powerdown

1 (0x01) LVDS

2 (0x02) LCPECL

3 (0x03) Reserved

4 (0x04) LVPECL (1600 mVpp)

5 (0x05) LVPECL (2000 mVpp)

6 (0x06) LVCMOS (Norm/Inv)

7 (0x07) LVCMOS (Inv/Norm)

8 (0x08) LVCMOS (Norm/Norm)

9 (0x09) LVCMOS (Inv/Inv)

10 (0x0A) LVCMOS (Off/Norm)

11 (0x0A) LVCMOS (Off/Inv)

12 (0x0C) LVCMOS (Norm/Off)

13 (0x0D) LVCMOS (Inv/Off)

14 (0x0E) LVCMOS (Off/Off)

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

8.6 REGISTER R3

8.6.1 CLKout12_13_ADLY

This registers controls the analog delay of the clock outputs 12 and 13. Adding analog delay to the output

will increase the noise floor of the output. For this analog delay to be active for a clock output, it must be

selected with ADLY12_SEL or ADLY13_SEL. If neither clock output selects the analog delay, then the

analog delay block is powered down.

In addition to the programmed delay, a fixed 500 ps of delay will be added by engaging the delay block.

The CLKout12_13_ADLY table shows the programming definition for these registers.

Table 8-15. CLKout12_13_ADLY, 6bits

R3[4:9] Definition

0 (0x00) 500 ps + No delay

1 (0x01) 500 ps + 25 ps

2 (0x02) 500 ps + 50 ps

3 (0x03) 500 ps + 75 ps

4 (0x04) 500 ps + 100 ps

5 (0x05) 500 ps + 125 ps

6 (0x06) 500 ps + 150 ps

7 (0x07) 500 ps + 175 ps

8 (0x08) 500 ps + 200 ps

9 (0x09) 500 ps + 225 ps

10 (0x0A) 500 ps + 250 ps

11 (0x0B) 500 ps + 275 ps

12 (0x0C) 500 ps + 300 ps

13 (0x0D) 500 ps + 325 ps

14 (0x0E) 500 ps + 350 ps

15 (0x0F) 500 ps + 375 ps

16 (0x10) 500 ps + 400 ps

17 (0x11) 500 ps + 425 ps

18 (0x12) 500 ps + 450 ps

19 (0x13) 500 ps + 475 ps

20 (0x14) 500 ps + 500 ps

21 (0x15) 500 ps + 525 ps

22 (0x16) 500 ps + 550 ps

23 (0x17) 500 ps + 575 ps

8.6.2 CLKout12_13_HS, Digital Delay Half Shift

This bit subtracts a half clock cycle of the clock distribution path period to the digital delay of CLKout12

and CLKout13. CLKout12_13_HS is used together with CLKout12_13_DDLY to set the digital delay value.

The state of this bit does not affect the power mode of the clock output group.

When changing CLKout12_13_HS, the digital delay immediately takes effect without a SYNC event.

Table 8-16. CLKout12_13_HS

R3[10] State

0 Normal

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

Table 8-16. CLKout12_13_HS (continued)

R3[10] State

1 Subtract half of a clock distribution path period from the total digital

delay

8.6.3 SYNC1_QUAL

When SYNC1_QUAL is set clock outputs on Bank B will be synchronized.

CLKout12 will be used as the SYNC qualification clock.

Only CLKout12 and CLKout13 support dynamic digital delay. However, this permits the relative phase

relationship between CLKout 12 and CLKout13 to be dynamically adjusted with respect to all other clock

outputs. When NO_SYNC_CLKoutX_Y = 1, the corresponding clock outputs will not be interrupted during

the SYNC event.

Qualifying the SYNC means that the pulse which turns the clock outputs off and on will have a fixed time

relationship with the phase of the other clock outputs.

See Section 6.9 for more information.

Table 8-17. SYNC1_QUAL

R3[11] Mode

0 (0x00) No Qualification

1 (0x01) Reserved

2 (0x10) Reserved

3 (0x11) Qualification Enabled

8.6.4 SYNCX_POL_INV

Sets the polarity of a SYNCX input pin. When SYNC is asserted the clock outputs will transition to a low

state.

A pull-up on the SYNCX pin results in normal operation when the SYNCX_POL_INV = 1 and the SYNCX

input is a no connect.

See Section 7.6 for more information on SYNC. A SYNC event can be generated by toggling this bit

through the MICROWIRE interface.

Table 8-18. SYNCX_POL_INV

R3[14, 15] Polarity

0 SYNC is active high

1 SYNC is active low

8.6.5 NO_SYNC_CLKoutX_Y

The NO_SYNC_CLKoutX_Y bits prevent individual clock groups from becoming synchronized during a

SYNC event. A reason to prevent individual clock groups from becoming synchronized is that during

synchronization, the clock output is in a fixed low state or can have a glitch pulse.

By disabling SYNC on a clock group, it will continue to operate normally during a SYNC event.

Digital delay requires a SYNC operation to take effect. If NO_SYNC_CLKout12_13 is set before a SYNC

event, the digital delay value will be unused.

Setting the NO_SYNC_CLKoutX_Y bit has no effect on clocks already synchronized together.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

Table 8-19. NO_SYNC_CLKoutX_Y Programming Addresses

NO_SYNC_CLKoutX_Y Programming Address

CLKout0 toCLKout3 R3[16]

CLKout4 to CLKout7 R3[17]

CLKout8 to CLKout11 R3[18]

CLKout12 to CLKout13 R3[19]

Table 8-20. NO_SYNC_CLKoutX_Y

R3[19, 18, 17, 16] Definition

0 CLKoutX_Y will synchronize

1 CLKoutX_Y will not synchronize

8.6.6 SYNCX_FAST

SYNC1_FAST must be set to 1 when using SYNC1_QUAL

8.6.7 SYNCX_AUTO

When set, causes a SYNC event to occur when programming R4 to adjust digital delay values (this will

cause a SYNC event for Bank B only) or R5 when adjusting divide values (this will cause a SYNC event

for both Bank A and B).

The SYNC event will coincide with the LE uWire pin falling edge.

Table 8-21. SYNCX_AUTO

R3[26, 25] Mode

0 Manual SYNC

1 SYNC internally generated

8.7 REGISTER R4

8.7.1 CLKout12_13_DDLY, Clock Channel Digital Delay

CLKout12_13_DDLY and CLKout12_13_HS sets the digital delay used for CLKout12 and CLKout13.

CLKout12_13_DDLY only takes effect during a SYNC event and if the NO_SYNC_CLKout12_13 bit is

cleared for this clock group.

Programming CLKout12_13_DDLY can require special attention. See section Section 7.6.1 for more

details.

Using a CLKout12_13_DDLY value of 13 or greater will cause the clock outputs to operate in extended

mode regardless of the clock group's divide value or the half step value.

One clock cycle is equal to the period of the clock distribution path. The period of the clock distribution

path is equal to clock divider value divided by the CLKin1 frequency.

tclock distribution path = CLKout divide value / fCLKin

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

Table 8-22. CLKout12_13_DDLY, 10 bits

R4[13:4] Delay Delay Power Mode

(Divide = 1) (Divide >1)

0 (0x00) 5 clock cycles 6 clock cycles

1 (0x01) 5 clock cycles 6 clock cycles

2 (0x02) 5 clock cycles 6 clock cycles

3 (0x03) 5 clock cycles 6 clock cycles

4 (0x04) 5 clock cycles 6 clock cycles Normal Mode

5 (0x05) 5 clock cycles 6 clock cycles

6 (0x06) 6 clock cycles 7 clock cycles

7 (0x07) 7 clock cycles 8 clock cycles

... ... ...

12 (0x0C) 12 clock cycles 13 clock cycles

13 (0x0D) 13 clock cycles 14 clock cycles

... ... ...

520 (0x208) 520 clock cycles 521 clock cycles Extended Mode

521 (0x209) 521 clock cycles 522 clock cycles

522 (0x20A) 522 clock cycles 523 clock cycles

8.8 REGISTER R5

8.8.1 CLKout12_ADLY_SEL[13], CLKout13_ADLY_SEL[14], Select Analog Delay

These bits individually select the analog delay block for use with CLKout12 or CLKout13. It is not required

for both outputs of a clock output group to use analog delay, but if both outputs do select the analog delay

block, then the analog delay will be the same for each output. When neither clock output uses analog

delay, the analog delay block is powered down.

Table 8-23. CLKout12_ADLY_SEL[13], CLKout13_ADLY_SEL[14]

R5[13] R5[14] State

0 0 Analog delay powered down

0 1 Analog delay on CLKout13

1 0 Analog delay on CLKout12

1 1 Analog delay on both CLKouts

8.8.2 CLKoutX_Y_DIV. Clock Output Divide

CLKoutX_Y_DIV sets the divide value for the clock outputs X through Y. The divide may be even or odd.

Both even and odd divides output a 50% duty cycle clock.

Programming CLKoutX_Y_DIV is as follows:

Table 8-24. CLKoutX_Y_DIV Programming Addresses

CLKoutX_Y_DIV Programming Address

CLKout0_3_DIV R5[6:4]

CLKout4_7_DIV R5[9:7]

CLKout8_11_DIV R5[12:10]

CLKout12_13_DIV R5[27:17]

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

Table 8-25. CLKoutX_Y_Div, 2 bits

R5[12:10, 9:7, 6:4] Divide Value

0 (0x00) 8

1 (0x01) 1

2 (0x02) 2

3 (0x03) 3

4 (0x04) 4

5 (0x05) 5

6 (0x06) 6

7 (0x07) 7

Table 8-26. CLKout12_13_DIV, 11 bits

R5[27:17] Divide Value Power Mode

0 (0x00) Invalid

1 (0x01) 1

2 (0x02) 2(1)

3 (0x03) 3

4 (0x04) 4 (1) Normal Mode

5 (0x05) 5 (1)

6 (0x06) 6

... ...

24 (0x18) 24

25 (0x19) 25

26 (0x1A) 26

27 (0x1B) 27

... ... Extended Mode

1044 (0x414) 1044

1045 (0x415) 1045

(1) After programming CLKout12_13_DIV a SYNC event must occur on the channels using this divide value (CLKout 12 and CLKout13), A

SYNC event may be generated by changing the SYNC1_POL_INV bit or through the SYNC1 pin. Ensure that CLKin1 is stable before

this SYNC event occurs.

Using a divide value of 26 or greater will cause the clock group to operate in extended mode regardless of

the clock group's digital delay value.

8.9 REGISTER 15

8.9.1 uWireLock

Setting uWireLock will prevent any changes to uWire registers R0 to R5. Only by clearing uWireLock bit in

R15 can the MICROWIRE registers be unlocked and written to once more.

Table 8-27. uWireLock

R15 [4] State

0 Registers Unlocked

1 Registers locked, Write-protected

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

9 Application Information

9.1 POWER SUPPLY

9.1.1 Current Consumption

NOTE

Assuming θJA = 25.8 °C/W, the total power dissipated on chip must be less than (125 °C - 85

°C) / 25.8 °C/W = 1.5 W to ensure a junction temperature less than 145 °C.

Worst case power dissipation can be estimated by multiplying typical power dissipation with

a factor of 1.20.

From Table 9-1 the current consumption can be calculated for any configuration.

For example, the current for the entire device with 1 LVDS (CLKout0) and 1 LVPECL 1600 mVpp /w 240

Ωemitter resistors (CLKout1) output active with a clock output divide = 1, and no other features enabled

can be calculated by adding the following blocks:

• Core Current

• Clock Buffer

• One LVDS Output Buffer Current

• Bank A

• Output Divider Buffer Current

• LVPECL 1600 mVpp buffer /w 240 Ωemitter resistors

Since there will be one LVPECL output drawing emitter current, this means some of the power from the

current draw of the device is dissipated in the external emitter resistors which doesn't add to the power

dissipation budget for the device but is important for LDO ICC calculations.

For total current consumption of the device add up the significant functional blocks. In this example 92 mA

• 1 mA (core current)

• 22 mA (Bank A current)

• 15 mA (Output Buffer current)

• 21 mA (Output Divider current)

• 9 mA (LVDS output current)

• 24 mA (LVPECL 1600 mVpp buffer /w 240 Ωemitter resistors)

Once the total current consumption has been calculated, power dissipated by the device can be

calculated. The power dissipation of the device is equel to the total current entering the device multiplied

by the voltage at the device minus the power dissipated in any emitter resistors connected to any of the

LVPECL outputs. If no emitter resistors are connected to the LVPECL outputs, this power will be 0 watts.

Continuing the output with 240 Ωemitter resistors. Total IC power = 275.1 mW = 3.3 V * 95 mA -28.5 mW.

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

Table 9-1. Typical Current Consumption for Selected Functional Blocks

(TA= 25 °C, VCC = 3.3 V)

Power

Power dissipated

Typical ICC dissipated

Block Condition externally

(mA) in device (mW)

(mW) (1)

Core

Core All outputs and dividers off 1 3.3 -

Bank A At least on output enabled 22 72.6 -

Bank Bank B At least on output enabled 25 82.5 -

CLKout0 to CLKout3 -

CLKout4 to CLKout7 -

On when any on output in the group is

Buffers 15 49.5

enabled

CLKout8 to CLKout11 -

CLKout12 to CLKout13 -

Divide = 1 21 69.3 -

CLKout0 to CLKout11 Divide = 2 to 8 24.2 79.8 -

Output

Divider Divide = 1 to 25 and DDLY = 1 to 12 15 49.5 -

CLKout12 and CLKout13 Divide = 26 to 1045 or DDLY > 13 19.1 63.0 -

Bank A Divide = 2 to 8 -

Input 9 29.7

Divider Bank B Divide = 2 to 8 -

CLKout12_13_ADLY = 0 to 3 3.4 11.2 -

CLKout12_13_ADLY = 4 to 7 3.8 12.5 -

Analog Delay Value CLKout12_13_ADLY = 8 to 11 4.2 13.9 -

Analog

Delay CLKout12_13_ADLY = 12 to 15 4.7 15.5 -

CLKout12_13_ADLY = 16 to 23 5.2 17.2 -

When only one, CLKout12 or CLKout13, have Analog Delay Selected. 2.8 9.2 -

Clock Output Buffers

CLkout0 to CLKout11; 100 Ωdifferential termination 9 29.7 -

LVDS CLkout12 to CLKout13; 100 Ωdifferential termination 14 46.2 -

CLkout0 to CLKout11; LVPECL 1600

mVpp, 24 79.2 28.5

AC coupled using 240 Ωemitter resistors

LVPEC

LCLkout12 to CLKout13; LVPECL 1600

mVpp, 29.5 97.3 28.5

AC coupled using 240 Ωemitter resistors 10 MHz 18.6 61.4 -

LVCMOS Pair, CLKout4 to CLKout11, 50 MHz 23.1 76.2 -

(CLKoutX_TYPE = 6 - 10), CL= 5 pF 150 MHz 31.7 104.6 -

10 MHz 24.7 81.51 -

LVCMOS Pair, CLKout12 and CLKout13, 50 MHz 30.3 100 -

(CLKoutX_TYPE = 6 - 10), CL= 5 pF 150 MHz 42.0 138.6 -

LVCMO

S10 MHz 9.7 32 -

LVCMOS Single, CLKout4 to CLKout11, 50 MHz 10.8 35.6 -

(CLKoutX_TYPE=11 - 13), CL= 5 pF 150 MHz 13.5 44.5 -

10 MHz 15 49.5 -

LVCMOS Single, CLKout12 and CLKout13, 50 MHz 17.5 57.7 -

(CLKoutX_TYPE= 11 - 13), CL= 5 pF 150 MHz 22.8 75.2 -

(1) Power is dissipated externally in LVPECL emitter resistors. The externally dissipated power is calculated as twice the DC voltage level

of one LVPECL clock output pin squared over the emitter resistance. That is to say power dissipated in emitter resistors = 2 * Vem2/Rem

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

9.2 PIN CONNECTION RECOMMENDATIONS

9.2.1 Vcc Pins and Decoupling

All Vcc pins must always be connected.

Integrated capacitance on the IC makes high frequency decoupling capacitors unnecessary. Ferrite beads

should be used on CLKout Vcc pins to minimize crosstalk through power supply. When several clocks

share the same frequency, a single ferrite bead can be shared with the common frequency CLKout Vcc's

for power supply isolation.

9.2.2 Unused clock outputs

Leave unused clock outputs floating and powered down.

9.2.3 Unused clock inputs

Unused clock inputs can be left floating.

9.2.4 Bias

Proper bypassing of the Bias pin with a 1 µF capacitor connected to Vcc4_Bias (Pin 25) is important for

low noise performance.

9.2.5 In MICROWIRE Mode

SYNC0 and SYNC1 have an internal pullup and may be left as a no-connect if external SYNC is not

required. MIRCROWIRE SYNC may still be used in this condition.

9.3 THERMAL MANAGEMENT

Power consumption of the LMK01801 can be high enough to require attention to thermal management.

For reliability and performance reasons the die temperature should be limited to a maximum of 125 °C.

That is, as an estimate, TA (ambient temperature) plus device power consumption times θJA should not

exceed 125 °C.

The package of the device has an exposed pad that provides the primary heat removal path as well as

excellent electrical grounding to a printed circuit board. To maximize the removal of heat from the package

a thermal land pattern including multiple vias to a ground plane must be incorporated on the PCB within

the footprint of the package. The exposed pad must be soldered down to ensure adequate heat

conduction out of the package.

A recommended footprint including recommended solder mask and solder paste layers can be found at:

http://www.ti.com/packaging for the RHS0048A package.

Submit Documentation Feedback

Product Folder Links: LMK01801

0.1 PF

0.1 PFLMK01801

Input

100:

100:Trace

(Differential)

Differential

Sinewave Clock

Source

CLKinX

CLKinX*

0.1 PF

0.1 PFLMK01801

Input

100:

100:Trace

(Differential)

CLKinX

CLKinX*

LVPECL

Ref Clk

240:240:

0.1 PF

0.1 PFLMK01801

Input

100:

100:Trace

(Differential)

CLKinX

CLKinX*

LVDS

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

9.4 DRIVING CLKin INPUTS

9.4.1 Driving CLKin Pins with a Differential Source

Both CLKin ports can be driven by differential signals. It is recommended that the input mode be set to

bipolar (CLKinX_BUF_TYPE = 0) when using differential reference clocks. The LMK01801 family internally

biases the input pins so the differential interface should be AC coupled. The recommended circuits for

driving the CLKin pins with either LVDS or LVPECL are shown in Figure 9-1 and Figure 9-2.

Figure 9-1. CLKinX/X* Termination for an LVDS

Reference Clock Source

Figure 9-2. CLKinX/X* Termination for an LVPECL

Reference Clock Source

Finally, a reference clock source that produces a differential sine wave output can drive the CLKin pins

using the circuit shown in Figure 9-3. Note: the signal level must conform to the requirements for the

CLKin pins listed in the Section 3.4.

Figure 9-3. CLKinX/X* Single-ended Termination

9.4.2 Driving CLKin Pins with a Single-Ended Source

The CLKin pins of the LMK01801 family can be driven using a single-ended reference clock source, for

example, either a sine wave source or an LVCMOS/LVTTL source. Either AC coupling or DC coupling

may be used. In the case of the sine wave source that is expecting a 50 Ωload, it is recommended that

AC coupling be used as shown in Figure 9-4 the circuit below with a 50 Ωtermination.

NOTE

The signal level must conform to the requirements for the CLKin pins listed in the

Section 3.4. CLKinX_BUF_TYPE is recommended to be set to bipolar mode

(CLKinX_BUF_TYPE = 0).

Submit Documentation Feedback

Product Folder Links: LMK01801

0.1 PF

50:Trace

50:LMK01801

Clock Source

CLKinX

CLKinX*

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

Figure 9-4. DC Coupled LVCMOS/LVTTL

Reference Clock

If the CLKin pins are being driven with a single-ended LVCMOS/ LVTTL source, either DC coupling or AC

coupling may be used. If DC coupling is used, see Figure 9-5, the CLKinX_BUF_TYPE should be set to

MOS buffer mode (CLKinX_BUF_TYPE = 1) and the voltage swing of the source must meet the

specifications for DC coupled, MOS-mode clock inputs given in the table of Electrical Characteristics. If

AC coupling is used, the CLKinX_BUF_TYPE should be set to the bipolar buffer mode

(CLKinX_BUF_TYPE = 0). The voltage swing at the input pins must meet the specifications for AC

coupled, bipolar mode clock inputs given in the table of Electrical Characteristics. In this case, some

attenuation of the clock input level may be required. A simple resistive divider circuit before the AC

coupling capacitor is sufficient.

Figure 9-5. DC Coupled LVCMOS/LVTTL Reference

Clock

9.5 TERMINATION AND USE OF CLOCK OUTPUT (DRIVERS)

When terminating clock drivers keep in mind these guidelines for optimum phase noise and jitter

performance:

• Transmission line theory should be followed for good impedance matching to prevent reflections.

• Clock drivers should be presented with the proper loads. For example:

– LVDS drivers are current drivers and require a closed current loop.

– LVPECL drivers are open emitters and require a DC path to ground.

• Receivers should be presented with a signal biased to their specified DC bias level (common mode

voltage) for proper operation. Some receivers have self-biasing inputs that automatically bias to the

proper voltage level. In this case, the signal should normally be AC coupled.

It is possible to drive a non-LVPECL or non-LVDS receiver with an LVDS or LVPECL driver as long as the

above guidelines are followed. Check the datasheet of the receiver or input being driven to determine the

best termination and coupling method to be sure that the receiver is biased at its optimum DC voltage

(common mode voltage).

For example, when driving the OSCin/OSCin* input of the LMK04800 family, OSCin/OSCin* should be AC

coupled because OSCin/ OSCin* biases the signal to the proper DC level. This is only slightly different

from the AC coupled cases described in Section 9.4.2 because the DC blocking capacitors are placed

between the termination and the OSCin/OSCin* pins, but the concept remains the same. The receiver

(OSCin/OSCin*) sets the input to the optimum DC bias voltage (common mode voltage), not the driver.

Submit Documentation Feedback

Product Folder Links: LMK01801

CLKoutX

CLKoutX*

LVPECL

Receiver

120:

100:Trace

(Differential)

120:

Vcc

LVPECL

Driver

82:82:

CLKoutX

CLKoutX*

LVPECL

Receiver

50:

100:Trace

(Differential)

50:

Vcc - 2 V

LVPECL

Driver

CLKoutX

CLKoutX*

LVDS

Receiver

100:

100:Trace

(Differential)

LVDS

Driver

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

9.5.1 Termination for DC Coupled Differential Operation

For DC coupled operation of an LVDS driver, terminate with 100 Ωas close as possible to the LVDS

receiver as shown in Figure 9-6.

Figure 9-6. Differential LVDS Operation, DC Coupling, No Biasing of the Receiver

For DC coupled operation of an LVPECL driver, terminate with 50 Ωto VCC - 2 V as shown in Figure 9-7.

Alternatively terminate with a Thevenin equivalent circuit (120 Ωresistor connected to VCC and an 82 Ω

resistor connected to ground with the driver connected to the junction of the 120 Ωand 82 Ωresistors) as

shown in Figure 9-8 for VCC = 3.3 V.

Figure 9-7. Differential LVPECL Operation, DC Coupling

Figure 9-8. Differential LVPECL Operation, DC Coupling, Thevenin Equivalent

9.5.2 Termination for AC Coupled Differential Operation

AC coupling allows for shifting the DC bias level (common mode voltage) when driving different receiver

standards. Since AC coupling prevents the driver from providing a DC bias voltage at the receiver it is

important to ensure the receiver is biased to its ideal DC level.

When driving non-biased LVDS receivers with an LVDS driver, the signal may be AC coupled by adding

DC blocking capacitors, however the proper DC bias point needs to be established at the receiver. One

way to do this is with the termination circuitry in Figure 9-9.

Submit Documentation Feedback

Product Folder Links: LMK01801

CLKoutX

CLKoutX*

RemRem

0.1 PF

Differential

Input

100:Trace

(Differential)

LVPECL

Driver

100:

0.1 PF

LVDS

Receiver

100:Trace

(Differential)

LVDS

Driver

100:

CLKoutX

CLKoutX*

0.1 PF

LVDS

Receiver

50:

100:Trace

(Differential)

LVDS

Driver

50:

Vbias

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

Figure 9-9. Differential LVDS Operation, AC Coupling, External Biasing at the Receiver

Some LVDS receivers may have internal biasing on the inputs. In this case, the circuit shown in is

modified by replacing the 50 Ωterminations to Vbias with a single 100 Ωresistor across the input pins of

the receiver, as shown in Figure 9-10. When using AC coupling with LVDS outputs, there may be a

startup delay observed in the clock output due to capacitor charging. The previous figures employ a 0.1

μF capacitor. This value may need to be adjusted to meet the startup requirements for a particular

application.

Figure 9-10. LVDS Termination for a Self-Biased Receiver

LVPECL drivers require a DC path to ground. When AC coupling an LVPECL signal use 120 Ωto 240 Ω

emitter resistors close to the LVPECL driver to provide a DC path to ground as shown in Figure 9-11. For

proper receiver operation, the signal should be biased to the DC bias level (common mode voltage)

specified by the receiver. The typical DC bias voltage for LVPECL receivers is 2 V.

A typical application is shown in Figure 9-11, where Rem=120 Ωto 240 Ω. Refer to the reciever input

recommendations to determine if the proper value of CA's, if needed.

Figure 9-11. Differential LVPECL Operation, AC Coupling,

External Biasing at the Receiver,

Rem=120 Ωto 240 Ω

9.5.3 Termination for Single-Ended Operation

A balun can be used with either LVDS or LVPECL drivers to convert the balanced, differential signal into

an unbalanced, single-ended signal.

Submit Documentation Feedback

Product Folder Links: LMK01801

CLKoutX

CLKoutX*

120:

0.1 PF

50:Trace

50:

Load

50:

LVPECL

Driver

CLKoutX

CLKoutX*

50:Trace

120:

Load

Vcc

82:

120:

Vcc

LVPECL

Driver

82:

CLKoutX

CLKoutX* 50:

50:Trace

50:

Load

Vcc - 2V

LVPECL

Driver

LMK01801

www.ti.com

SNAS573A –JANUARY 2012–REVISED APRIL 2013

It is possible to use an LVPECL driver as one or two separate 800 mVpp signals. When using only one

LVPECL driver of a CLKoutX/CLKoutX* pair, be sure to properly terminated the unused driver. When DC

coupling one of the LMK04800 family clock LVPECL drivers, the termination should be 50 Ωto VCC - 2 V

as shown in Figure 9-12. The Thevenin equivalent circuit is also a valid termination as shown in Figure 9-

13 for Vcc = 3.3 V.

Figure 9-12. Single-Ended LVPECL Operation,

DC Coupling

Figure 9-13. Single-Ended LVPECL Operation, DC

Coupling, Thevenin Equivalent

When AC coupling an LVPECL driver use a 120 Ωto 240 Ωemitter resistor to provide a DC path to

ground and ensure a 50 Ωtermination with the proper DC bias level for the receiver. The typical DC bias

voltage for LVPECL receivers is 2 V (See Section 9.5.2). If the companion driver is not used it should be

terminated with either a proper AC or DC termination. This latter example of AC coupling a single-ended

LVPECL signal can be used to measure single-ended LVPECL performance using a spectrum analyzer or

phase noise analyzer. When using most RF test equipment no DC bias point (0 VDC) is required for safe

and proper operation. The internal 50 Ωtermination of the test equipment correctly terminates the

LVPECL driver being measured as shown in Figure 9-14.

Figure 9-14. Single-Ended LVPECL Operation, AC Coupling

Rem=120 Ωto 240 Ω

Submit Documentation Feedback

Product Folder Links: LMK01801

LMK01801

SNAS573A –JANUARY 2012–REVISED APRIL 2013

www.ti.com

Revision History

NOTE: Page numbers for previous revisions may differ from page numbers in the current version.

Changes from Original (April 2013) to Revision A Page

• Changed layout of National Data Sheet to TI format .......................................................................... 45

Submit Documentation Feedback

Product Folder Links: LMK01801

PACKAGE OPTION ADDENDUM

www.ti.com 19-Apr-2013

Addendum-Page 1

PACKAGING INFORMATION

Orderable Device Status

(1)

Package Type Package

Drawing Pins Package

Qty Eco Plan

(2)

Lead/Ball Finish MSL Peak Temp

(3)

Op Temp (°C) Top-Side Markings

(4)

Samples

LMK01801BISQ/NOPB ACTIVE WQFN RHS 48 1000 Green (RoHS

& no Sb/Br) CU SN Level-3-260C-168 HR -40 to 85 K01801BI

LMK01801BISQE/NOPB ACTIVE WQFN RHS 48 250 Green (RoHS

& no Sb/Br) CU SN Level-3-260C-168 HR -40 to 85 K01801BI

LMK01801BISQX/NOPB ACTIVE WQFN RHS 48 2500 Green (RoHS

& no Sb/Br) CU SN Level-3-260C-168 HR -40 to 85 K01801BI

(1) The marketing status values are defined as follows:

ACTIVE: Product device recommended for new designs.

LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.

NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.

PREVIEW: Device has been announced but is not in production. Samples may or may not be available.

OBSOLETE: TI has discontinued the production of the device.

(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability

information and additional product content details.

TBD: The Pb-Free/Green conversion plan has not been defined.

Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that

lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.

Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between

the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.

Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight

in homogeneous material)

(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

(4) Multiple Top-Side Markings will be inside parentheses. Only one Top-Side Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a

continuation of the previous line and the two combined represent the entire Top-Side Marking for that device.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information

provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and

continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.

TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

TAPE AND REEL INFORMATION

*All dimensions are nominal

Device Package

Type Package

Drawing Pins SPQ Reel

Diameter

(mm)

Reel

Width

W1 (mm)

(mm) B0

(mm) K0

(mm) P1

(mm) W

(mm) Pin1

Quadrant

LMK01801BISQ/NOPB WQFN RHS 48 1000 330.0 16.4 7.3 7.3 1.3 12.0 16.0 Q1

LMK01801BISQE/NOPB WQFN RHS 48 250 178.0 16.4 7.3 7.3 1.3 12.0 16.0 Q1

LMK01801BISQX/NOPB WQFN RHS 48 2500 330.0 16.4 7.3 7.3 1.3 12.0 16.0 Q1

PACKAGE MATERIALS INFORMATION

www.ti.com 20-Sep-2016

Pack Materials-Page 1

*All dimensions are nominal

Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)

LMK01801BISQ/NOPB WQFN RHS 48 1000 367.0 367.0 38.0

LMK01801BISQE/NOPB WQFN RHS 48 250 210.0 185.0 35.0

LMK01801BISQX/NOPB WQFN RHS 48 2500 367.0 367.0 38.0

PACKAGE MATERIALS INFORMATION

www.ti.com 20-Sep-2016

Pack Materials-Page 2

www.ti.com

PACKAGE OUTLINE

SEE TERMINAL

DETAIL

48X 0.30

0.18

5.1 0.1

48X 0.5

0.3

0.8

0.7

(A) TYP

0.05

0.00

44X 0.5

5.5

2X 5.5

A7.15

6.85 B

7.15

6.85

0.30

0.18

0.5

0.3

(0.2)

WQFN - 0.8 mm max heightRHS0048A

PLASTIC QUAD FLATPACK - NO LEAD

4214990/B 04/2018

DIM A

OPT 1 OPT 2

(0.1) (0.2)

PIN 1 INDEX AREA

0.08 C

SEATING PLANE

12 25

13 24

48 37

(OPTIONAL)

PIN 1 ID 0.1 C A B

0.05

EXPOSED

THERMAL PAD

49 SYMM

SYMM

NOTES:

1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing

per ASME Y14.5M.

2. This drawing is subject to change without notice.

3. The package thermal pad must be soldered to the printed circuit board for thermal and mechanical performance.

SCALE 1.800

DETAIL

OPTIONAL TERMINAL

TYPICAL

www.ti.com

EXAMPLE BOARD LAYOUT

0.07 MIN

ALL AROUND

0.07 MAX

ALL AROUND

48X (0.25)

48X (0.6)

( 0.2) TYP

VIA

44X (0.5)

(6.8)

(1.25) TYP

( 5.1)

(R0.05)

TYP

(1.25)

TYP

(1.05) TYP

(1.05)

TYP

WQFN - 0.8 mm max heightRHS0048A

PLASTIC QUAD FLATPACK - NO LEAD

4214990/B 04/2018

SYMM

13 24

SYMM

LAND PATTERN EXAMPLE

EXPOSED METAL SHOWN

SCALE:12X

NOTES: (continued)

4. This package is designed to be soldered to a thermal pad on the board. For more information, see Texas Instruments literature

number SLUA271 (www.ti.com/lit/slua271).

5. Vias are optional depending on application, refer to device data sheet. If any vias are implemented, refer to their locations shown

on this view. It is recommended that vias under paste be filled, plugged or tented.

SOLDER MASK

OPENING

METAL UNDER

SOLDER MASK

DEFINED

EXPOSED

METAL

METAL EDGE

SOLDER MASK

OPENING

SOLDER MASK DETAILS

NON SOLDER MASK

DEFINED

(PREFERRED)

EXPOSED

METAL

www.ti.com

EXAMPLE STENCIL DESIGN

48X (0.6)

48X (0.25)

44X (0.5)

(6.8)

16X

( 1.05)

(0.625) TYP

(R0.05) TYP

(1.25)

TYP

(1.25)

TYP

(0.625) TYP

WQFN - 0.8 mm max heightRHS0048A

PLASTIC QUAD FLATPACK - NO LEAD

4214990/B 04/2018

NOTES: (continued)

6. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate

design recommendations.

SYMM

METAL

TYP

SOLDER PASTE EXAMPLE

BASED ON 0.125 mm THICK STENCIL

EXPOSED PAD 49

68% PRINTED SOLDER COVERAGE BY AREA UNDER PACKAGE

SCALE:15X

SYMM

13 24

IMPORTANT NOTICE

Texas Instruments Incorporated (TI) reserves the right to make corrections, enhancements, improvements and other changes to its

semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers

should obtain the latest relevant information before placing orders and should verify that such information is current and complete.

TI’s published terms of sale for semiconductor products (http://www.ti.com/sc/docs/stdterms.htm) apply to the sale of packaged integrated

circuit products that TI has qualified and released to market. Additional terms may apply to the use or sale of other types of TI products and

services.

Reproduction of significant portions of TI information in TI data sheets is permissible only if reproduction is without alteration and is

accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such reproduced

documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements

different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the

associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.

Buyers and others who are developing systems that incorporate TI products (collectively, “Designers”) understand and agree that Designers

remain responsible for using their independent analysis, evaluation and judgment in designing their applications and that Designers have

full and exclusive responsibility to assure the safety of Designers' applications and compliance of their applications (and of all TI products

used in or for Designers’ applications) with all applicable regulations, laws and other applicable requirements. Designer represents that, with

respect to their applications, Designer has all the necessary expertise to create and implement safeguards that (1) anticipate dangerous

consequences of failures, (2) monitor failures and their consequences, and (3) lessen the likelihood of failures that might cause harm and

take appropriate actions. Designer agrees that prior to using or distributing any applications that include TI products, Designer will

thoroughly test such applications and the functionality of such TI products as used in such applications.

TI’s provision of technical, application or other design advice, quality characterization, reliability data or other services or information,

including, but not limited to, reference designs and materials relating to evaluation modules, (collectively, “TI Resources”) are intended to

assist designers who are developing applications that incorporate TI products; by downloading, accessing or using TI Resources in any

way, Designer (individually or, if Designer is acting on behalf of a company, Designer’s company) agrees to use any particular TI Resource

solely for this purpose and subject to the terms of this Notice.

TI’s provision of TI Resources does not expand or otherwise alter TI’s applicable published warranties or warranty disclaimers for TI

products, and no additional obligations or liabilities arise from TI providing such TI Resources. TI reserves the right to make corrections,

enhancements, improvements and other changes to its TI Resources. TI has not conducted any testing other than that specifically

described in the published documentation for a particular TI Resource.

Designer is authorized to use, copy and modify any individual TI Resource only in connection with the development of applications that

include the TI product(s) identified in such TI Resource. NO OTHER LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE

TO ANY OTHER TI INTELLECTUAL PROPERTY RIGHT, AND NO LICENSE TO ANY TECHNOLOGY OR INTELLECTUAL PROPERTY

RIGHT OF TI OR ANY THIRD PARTY IS GRANTED HEREIN, including but not limited to any patent right, copyright, mask work right, or

other intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information

regarding or referencing third-party products or services does not constitute a license to use such products or services, or a warranty or

endorsement thereof. Use of TI Resources may require a license from a third party under the patents or other intellectual property of the

third party, or a license from TI under the patents or other intellectual property of TI.

TI RESOURCES ARE PROVIDED “AS IS” AND WITH ALL FAULTS. TI DISCLAIMS ALL OTHER WARRANTIES OR

REPRESENTATIONS, EXPRESS OR IMPLIED, REGARDING RESOURCES OR USE THEREOF, INCLUDING BUT NOT LIMITED TO

ACCURACY OR COMPLETENESS, TITLE, ANY EPIDEMIC FAILURE WARRANTY AND ANY IMPLIED WARRANTIES OF

MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF ANY THIRD PARTY INTELLECTUAL

PROPERTY RIGHTS. TI SHALL NOT BE LIABLE FOR AND SHALL NOT DEFEND OR INDEMNIFY DESIGNER AGAINST ANY CLAIM,

INCLUDING BUT NOT LIMITED TO ANY INFRINGEMENT CLAIM THAT RELATES TO OR IS BASED ON ANY COMBINATION OF

PRODUCTS EVEN IF DESCRIBED IN TI RESOURCES OR OTHERWISE. IN NO EVENT SHALL TI BE LIABLE FOR ANY ACTUAL,

DIRECT, SPECIAL, COLLATERAL, INDIRECT, PUNITIVE, INCIDENTAL, CONSEQUENTIAL OR EXEMPLARY DAMAGES IN

CONNECTION WITH OR ARISING OUT OF TI RESOURCES OR USE THEREOF, AND REGARDLESS OF WHETHER TI HAS BEEN

ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

Unless TI has explicitly designated an individual product as meeting the requirements of a particular industry standard (e.g., ISO/TS 16949

and ISO 26262), TI is not responsible for any failure to meet such industry standard requirements.

Where TI specifically promotes products as facilitating functional safety or as compliant with industry functional safety standards, such

products are intended to help enable customers to design and create their own applications that meet applicable functional safety standards

and requirements. Using products in an application does not by itself establish any safety features in the application. Designers must

ensure compliance with safety-related requirements and standards applicable to their applications. Designer may not use any TI products in

life-critical medical equipment unless authorized officers of the parties have executed a special contract specifically governing such use.

Life-critical medical equipment is medical equipment where failure of such equipment would cause serious bodily injury or death (e.g., life

support, pacemakers, defibrillators, heart pumps, neurostimulators, and implantables). Such equipment includes, without limitation, all

medical devices identified by the U.S. Food and Drug Administration as Class III devices and equivalent classifications outside the U.S.

TI may expressly designate certain products as completing a particular qualification (e.g., Q100, Military Grade, or Enhanced Product).

Designers agree that it has the necessary expertise to select the product with the appropriate qualification designation for their applications

and that proper product selection is at Designers’ own risk. Designers are solely responsible for compliance with all legal and regulatory

requirements in connection with such selection.

Designer will fully indemnify TI and its representatives against any damages, costs, losses, and/or liabilities arising out of Designer’s non-

compliance with the terms and provisions of this Notice.

Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265

Mouser Electronics

Authorized Distributor

Click to View Pricing, Inventory, Delivery & Lifecycle Information:

Texas Instruments:

LMK01801BISQ/NOPB LMK01801BISQE/NOPB LMK01801BISQX/NOPB