MAX4889CETO+T - Maxim Integrated

General Description

The MAX4889B/MAX4889C high-speed passive switch-

es route PCI Express®(PCIe) data between two possi-

ble destinations in desktop or notebook PCs. The

MAX4889B/MAX4889C are quad double-pole/double-

throw (4 x DPDT) switches ideal for switching four half

lanes of PCIe data between two destinations. The

MAX4889B/MAX4889C feature a single digital control

input (SEL) to switch signal paths.

The MAX4889C is intended for use in systems (e.g.,

SAS) where both the input and output are capacitively

coupled, and provides a 10µA (typ) source current and

a 60kΩ(typ) internal biasing resistor to GND at the

_OUT_ terminals.

The MAX4889B/MAX4889C are fully specified to oper-

ate from a single +3.3V (typ) power supply. Both

devices are available in an industry-standard 3.5mm x

9.0mm, 42-pin TQFN package. These devices operate

over the -40°C to +85°C extended temperature range.

Applications

Desktop PCs

Notebook PCs

Servers

Video Graphics Cards—SLI®

(Scaled Link Interface) and CrossFire™

Features

♦Single +3.3V Power-Supply Voltage

♦Support PCIe Gen I, Gen II, and Gen III Data Rates

♦Supports SAS I, SAS II, and SAS 6.0Gbps

(MAX4889C)

♦Superior Return Loss

Better than -10dB (typ) at 5.0GHz

♦Small 3.5mm x 9.0mm, 42-Pin TQFN Package

♦Industry-Standard Pinouts

MAX4889B/MAX4889C

2.5/5.0/8.0Gbps PCIe Passive Switches

________________________________________________________________

Maxim Integrated Products

Ordering Information

19-4148; Rev 2; 8/10

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

Denotes a lead(Pb)-free/RoHS-compliant package.

EP = Exposed pad.

EVALUATION KIT

AVAILABLE

PART TEMP RANGE PIN-PACKAGE

MAX4889BETO+ -40°C to +85°C 42 TQFN-EP*

MAX4889CETO+ -40°C to +85°C 42 TQFN-EP*

Pin Configuration

TOP VIEW

MAX4889B

MAX4889C

TQFN

GND

VCC

GND

VCC

42 +

GND

VCC

GND

VCC

1 2 3 4 5 6 7 8 9 1011121314151617

38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22

COUTB+

COUTB-

DIN+

DIN-

DOUTB+

DOUTB-

CIN-

CIN+

VCC

BOUTB-

BOUTB+

BIN-

BIN+

AOUTB-

AOUTB+

AIN-

AIN+

COUTA-

VCC

GND

DOUTA+

DOUTA-

GND

COUTA+

GND

SEL

VCC

BOUTA-

BOUTA+

VCC

GND

AOUTA-

AOUTA+

GND

*CONNECT EXPOSED PAD TO GROUND.

*EP

PCI Express is a registered service mark of PCI-SIG Corporation.

SLI is a registered trademark of NVIDIA Corporation.

CrossFire is a trademark of ATI Technologies, Inc.

Typical Operating Circuit appears at end of data sheet.

MAX4889B/MAX4889C

2.5/5.0/8.0Gbps PCIe Passive Switches

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC = +3.3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V, TA= +25°C, unless otherwise

noted.) (Note 3)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional

operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to

absolute maximum rating conditions for extended periods may affect device reliability.

(All voltages referenced to GND, unless otherwise noted.)

VCC ...........................................................................-0.3V to +4V

SEL, _IN_, _OUTA_, _OUTB_ (Note 1) .......-0.3V to (VCC + 0.3V)

Continuous Current (AIN_ to AOUTA_/AOUTB_, BIN_ to

BOUTA_/BOUTB_, CIN_ to COUTA_/COUTB_, DIN_ to

DOUTA_/DOUTB_) .........................................................±70mA

Peak Current (AIN_ to AOUTA_/AOUTB_, BIN_ to

BOUTA_/BOUTB_, CIN_ to COUTA_/COUTB_, DIN_ to

DOUTA_/DOUTB_)

(pulsed at 1ms, 10% duty cycle)..............................±70mA

Continuous Current (SEL).................................................±10mA

Peak Current (SEL)

(pulsed at 1ms, 10% duty cycle)..................................±10mA

Continuous Power Dissipation (TA= +70°C) for multilayer board:

42-Pin TQFN (derate 35.7mW/°C above +70°C) .......2857mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Package Junction-to-Ambient Thermal Resistance

(θJA) (Note 2) ............................................................28.0°C/W

Package Junction-to-Case Thermal Resistance

(θJC) (Note 2) ..............................................................2.0°C/W

Lead Temperature (soldering, 10s) .................................+300°C

Soldering Temperature (reflow) .......................................+260°C

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DC PERFORMANCE

Analog Signal Range

_IN_,

_OUTA_,

_OUTB_

-0.3

VCC -

1.8 V

On-Resistance RON VCC = +3.0V, I_IN_ = 15mA, V_OUTA_,

V_OUTB_ = 0V, 1.2V 6.4 8.4 

On-Resistance Match Between

Pairs of Same Channel RON VCC = +3.0V, I_IN_ = 15mA, V_OUTA_,

V_OUTB_ = 0V (Notes 4, 5) 0.1 0.5 

On-Resistance Match Between

Channels RON VCC = +3.0V, I_IN_ = 15mA, V_OUTA_,

V_OUTB_ = 0V (Notes 4, 5) 0.2 

On-Resistance Flatness RFLAT (ON) VCC = +3.0V, I_IN_ = 15mA, V_OUTA_,

V_OUTB_ = 0V, 1.2V (Notes 5, 6) 0.3 

_OUTA_ or _OUTB_ Off-Leakage

Current

I_OUTA_ (OFF),

I_OUTB_ (OFF)

VCC = +3.6V, V_IN_ = 0V, 1.2V, V_OUTA_

or V_OUTB_ = 1.2V, 0V (MAX4889B) -1 +1 μA

_IN_ On-Leakage Current I_IN_ (ON)

VCC = +3.6V, V_IN_ = 0V, 1.2V, V_OUTA_

or V_OUTB_ = V_IN_ or unconnected

(MAX4889B)

-1 +1 μA

Output Short-Circuit Current All other ports are unconnected

(MAX4889C) 515μA

Output Open-Circuit Voltage All other ports are unconnected

(MAX4889C) 0.2 0.6 0.9 V

Note 1: Signals on SEL, _IN_, _OUTA_, _OUTB_ exceeding VCC or GND are clamped by internal diodes. Limit forward-diode current

to maximum current rating.

Note 2: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer

board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.

FREQUENCY RANGE

(GHz)

MAXIMUM INSERTION

LOSS (dB)

0–2.5

fGHz +0.6

2.5–5

fGHz -1.0

5 or greater

fGHz -3.0

MAX4889B/MAX4889C

2.5/5.0/8.0Gbps PCIe Passive Switches

_______________________________________________________________________________________ 3

Note 3: All units are 100% production tested at TA= +85°C. Limits over the operating temperature range are guaranteed by design

and characterization and are not production tested.

Note 4: ΔRON = RON (MAX) - RON (MIN).

Note 5: Guaranteed by design, not production tested.

Note 6: Flatness is defined as the difference between the maximum and minimum value of on-resistance as measured over the

specified analog signal range.

ELECTRICAL CHARACTERISTICS (continued)

(VCC = +3.3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V, TA= +25°C, unless otherwise

noted.) (Note 3)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

AC PERFORMANCE

SEL-to-Switch Turn-On Time tON_SEL Z

S = ZL= 50 80 ns

SEL-to-Switch Turn-Off Time tOFF_SEL Z

S = ZL= 50, Figure 1 15 ns

Propagation Delay tPD Z

S = ZL= 50, Figure 2 50 ps

Output Skew Between Pairs tSKEW1 Z

S = ZL= 50, Figure 2 50 ps

Output Skew Between Same Pair tSKEW2 Z

S = ZL= 50, Figure 2 10 ps

0Hz < f  2.8GHz -14

2.8GHz < f  5.0GHz -8

Differential Return Loss (Note 5) SDD11

f > 5.0GHz -3

Differential Insertion Loss (Note 5) SDD21 See Table 1 dB

0Hz < f  2.5GHz -40

2.5GHz < f  5.0GHz -30

Differential Crosstalk (Note 5) SDDCTK

f > 5.0GHz -25

0Hz < f  2.5GHz -15

2.5GHz < f  5.0GHz -12

Differential Off-Isolation (Note 5) SDD21_OFF

f > 5.0GHz -12

CONTROL INPUT (SEL)

Input Logic High VIH 1.4 V

Input Logic Low VIL 0.6 V

Input Logic Hysteresis VHYST 130 mV

POWER SUPPLY

Power-Supply Range VCC 3.0 3.6 V

VCC Supply Current ICC V

SEL = 0V or VCC 1 mA

Table 1. Insertion Loss Mask

MAX4889B/MAX4889C

2.5/5.0/8.0Gbps PCIe Passive Switches

4 _______________________________________________________________________________________

Test Circuits/Timing Diagrams

LOAD

SOURCE

VOUT

MAX4889B/

MAX4889C

SEL

10%

90%

50%

tON_SEL tOFF_SEL

VOUT

SEL

THE FREQUENCY OF THE SIGNAL SHOULD BE ABOVE THE HIGHPASS FILTER CORNER OF THE COUPLING CAPACITORS.

Figure 1. Switching Time

MAX4889B/MAX4889C

2.5/5.0/8.0Gbps PCIe Passive Switches

Test Circuits/Timing Diagrams (continued)

LOAD

SOURCE

VOUTp

VOUTn

MAX4889B/

MAX4889C

SEL

CALIBRATION

TRACES

VS+

VS-

VCALp

VCALn

VSC+

VSC-

50%50%

VCM

50%50%

VCM

tPDr tPDf

tSK1 tSK2

VOUTn

THE FREQUENCY OF THE SIGNALS SHOULD BE APPROXIMATELY 1/20 OF THE LOWEST DATA RATE.

VOUTp

tPD = max (tPDr, tPDf)

tSKEW = max (tSK1, tSK2)

VOUTp - VOUTn

VCALp - VCALn

Figure 2. Propagation Delay and Output Skew

_______________________________________________________________________________________ 5

MAX4889B/MAX4889C

2.5/5.0/8.0Gbps PCIe Passive Switches

6 _______________________________________________________________________________________

Typical Operating Characteristics

(VCC = +3.3V, TA= +25°C, unless otherwise noted.)

4.0

5.5

5.0

4.5

6.5

6.0

7.5

7.0

8.0

0 0.6 1.2 1.8

ON-RESISTANCE vs. V_IN_

MAX4889B/9C toc01

V_IN_ (V)

RON (Ω)

VCC = +3.0V

VCC = +3.6V

VCC = +3.3V

0 0.3 0.6 0.9 1.2 1.5

ON-RESISTANCE vs. V_IN_

MAX4889B/9C toc02

V_IN_ (V)

RON (Ω)

TA = +85°C

TA = -40°C TA = +25°C

250

350

300

500

450

400

650

600

550

700

-40 10-15 35 60 85

SUPPLY CURRENT

vs. TEMPERATURE

MAX4889B/9C toc03

TEMPERATURE (°C)

SUPPLY CURRENT (μA)

MAX4889B

MAX4889C

VCC = +3.6V

VCC = +3.3V

VCC = +3.0V

VCC = +3.6V

VCC = +3.3V

VCC = +3.0V

0.9

1.0

1.2

1.1

1.3

1.4

3.0 3.23.1 3.3 3.4 3.5 3.6

LOGIC THRESHOLD

vs. SUPPLY VOLTAGE

MAX4889B/9C toc04

VCC (V)

LOGIC THRESHOLD (V)

VIH

VIL

TURN-ON/-OFF TIME

vs. SUPPLY VOLTAGE

MAX4889B/9C toc05

VCC (V)

TURN-ON/-OFF TIME (ns)

3.0 3.4 3.53.2 3.33.1 3.6

tON_SEL

tOFF_SEL

-20

-16

-18

-12

-14

-8

-10

-6

-2

-4

0246810

DIFFERENTIAL INSERTION LOSS

vs. FREQUENCY

MAX4889B/9C toc06

FREQUENCY (GHz)

DIFFERENTIAL INSERITON LOSS (dB)

MAX4889B

MAX4889C

MASK

-50

-40

-45

-30

-35

-20

-25

-15

-5

-10

0246810

DIFFERENTIAL OFF-ISOLATION

vs. FREQUENCY

MAX4889B/9C toc07

FREQUENCY (GHz)

DIFFERENTIAL OFF-ISOLATION (dB)

-80

-60

-70

-50

-20

-10

-30

-40

0246810

DIFFERENTIAL CROSSTALK

vs. FREQUENCY

MAX4889B/9C toc08

FREQUENCY (GHz)

DIFFERENTIAL CROSSTALK (dB)

-40

-30

-35

-25

-10

-5

-15

-20

0246810

DIFFERENTIAL RETURN LOSS

vs. FREQUENCY

MAX4889B/9C toc09

FREQUENCY (GHz)

DIFFERENTIAL RETURN LOSS (dB)

MAX4889B

MAX4889C

MASK

MAX4889B/MAX4889C

2.5/5.0/8.0Gbps PCIe Passive Switches

_______________________________________________________________________________________ 7

GND

VCC VCC

AIN+

AIN-

DIN+

DIN-

SEL

AOUTA+

AOUTA-

AOUTB+

AOUTB-

BIN+

BIN-

BOUTA+

BOUTA-

BOUTB+

BOUTB-

CIN+

CIN-

COUTA+

COUTA-

COUTB+

COUTB-

DOUTA+

DOUTA-

DOUTB+

DOUTB-

SEL

0 (DEFAULT)

_IN_ TO

_OUTA_

OFF

_IN_ TO

_OUTB_

OFF

MAX4889CMAX4889B

CONTROL

GND

SEL

DIN+

DIN-

DOUTA+

DOUTA-

DOUTB+

DOUTB-

CIN+

CIN-

COUTA+

COUTA-

COUTB+

COUTB-

BIN+

BIN-

BOUTA+

BOUTA-

BOUTB+

BOUTB-

AIN+

AIN-

AOUTA+

AOUTA-

AOUTB+

AOUTB-

CONTROL

Functional Diagram/Truth Table

MAX4889B/MAX4889C

2.5/5.0/8.0Gbps PCIe Passive Switches

8 _______________________________________________________________________________________

Pin Description

MAX4889B/

MAX4889C

NAME FUNCTION

1 AIN+ Analog Switch 1. Common Positive Terminal.

2 AIN- Analog Switch 1. Common Negative Terminal.

3 AOUTB+ Analog Switch 1. Normally Open Positive Terminal.

4 AOUTB- Analog Switch 1. Normally Open Negative Terminal.

5 BIN+ Analog Switch 2. Common Positive Terminal.

6 BIN- Analog Switch 2. Common Negative Terminal.

7 BOUTB+ Analog Switch 2. Normally Open Positive Terminal.

8 BOUTB- Analog Switch 2. Normally Open Negative Terminal.

9, 19, 21, 26, 31,

34, 39, 41 VCC P osi ti ve S up p l y V ol tag e Inp ut. C onnect V

C C

to a 3.0V to 3.6V sup p l y vol tag e. Byp ass V

C C

to GN D w i th

a 0.1µF cer am i c cap aci tor p l aced as cl ose as p ossi b l e to the d evi ce. S ee the Boar d Layout secti on.

10 CIN+ Analog Switch 3. Common Positive Terminal.

11 CIN- Analog Switch 3. Common Negative Terminal.

12 COUTB+ Analog Switch 3. Normally Open Positive Terminal.

13 COUTB- Analog Switch 3. Normally Open Negative Terminal.

14 DIN+ Analog Switch 4. Common Positive Terminal.

15 DIN- Analog Switch 4. Common Negative Terminal.

16 DOUTB+ Analog Switch 4. Normally Open Positive Terminal.

17 DOUTB- Analog Switch 4. Normally Open Negative Terminal.

18, 20, 22, 25, 29,

35, 38, 40, 42 GND Ground

23 DOUTA- Analog Switch 4. Normally Closed Negative Terminal.

24 DOUTA+ Analog Switch 4. Normally Closed Positive Terminal.

27 COUTA- Analog Switch 3. Normally Closed Negative Terminal.

28 COUTA+ Analog Switch 3. Normally Closed Positive Terminal.

30 SEL Control Signal Input. SEL has a 70kΩ (typ) pulldown resistor to GND.

32 BOUTA - Analog Switch 2. Normally Closed Negative Terminal.

33 BOUTA+ Analog Switch 2. Normally Closed Positive Terminal.

36 AOUTA- Analog Switch 1. Normally Closed Negative Terminal.

37 AOUTA+ Analog Switch 1. Normally Closed Positive Terminal.

— EP Exposed Pad. Connect EP to GND.

Detailed Description

The MAX4889B high-speed passive switch routes PCI

Express (PCIe) data or other high-speed signals with

amplitude of ≤1.2VP-P differential, and common-mode

voltage close to 0V between two possible destinations.

The MAX4889B is ideal for routing PCIe signals to

change system configuration. For example, in a graphics

application, four MAX4889B devices create two sets of

eight lanes from a single 16-lane bus. The MAX4889C

feature a 10µA (typ) source current and a 60kΩ(typ)

internal biasing resistor to GND at the _OUT_ terminals.

The MAX4889C is ideal for dual capacitively coupled

applications such as SAS and SATA. The MAX4889B/

MAX4889C feature a single digital control input (SEL) to

switch signal paths. SEL has a 70kΩ(typ) pulldown

resistor to GND.

The MAX4889B/MAX4889C are fully specified to oper-

ate from a single 3.0V to 3.6V power supply.

Digital Control Input (SEL)

The MAX4889B/MAX4889C provide a single digital

control input (SEL) to select the signal path between

the _IN_ and _OUT_ channels. The truth tables for the

MAX4889B/MAX4889C are illustrated in the

Functional

Diagram/Truth Table

. SEL has a 70kΩ(typ) pulldown

resistor to GND.

Analog Signal Levels

The MAX4889B/MAX4889C accept standard PCIe signals

to a maximum of (VCC - 1.8V). Signals on the _IN+ chan-

nels are routed to either the _OUTA+ or _OUTB+ chan-

nels. Signals on the _IN- channels are routed to either the

_OUTA- or _OUTB- channels. The MAX4889B/MAX4889C

are bidirectional switches, allowing _IN_ and _OUT_ to be

used as either inputs or outputs.

Applications Information

PCIe Switching

The MAX4889B/MAX4889C primary applications are

aimed at reallocating PCIe lanes (see the

Typical

Operating Circuit: Video Graphics Cards

). For example,

in graphics applications, several manufacturers have

found that it is possible to improve performance by a fac-

tor of nearly two by splitting a single 16-lane PCIe bus

into two 8-lane buses. Two of the more prominent exam-

ples are SLI (Scaled Link Interface) and CrossFire. Four

MAX4889Bs permit a computer motherboard to operate

properly with a single 16-lane graphics card, which can

later be upgraded to dual cards.

Board Layout

High-speed switches require proper layout and design

procedures for optimum performance. Keep controlled-

impedance PCB traces as short as possible or follow

impedance layouts per the PCIe specification. Ensure

that power-supply bypass capacitors are placed as

close as possible to the device. Multiple bypass capac-

itors are recommended. Connect all grounds and the

exposed pad to large ground planes.

MAX4889B/MAX4889C

2.5/5.0/8.0Gbps PCIe Passive Switches

_______________________________________________________________________________________ 9

MAX4889B/MAX4889C

2.5/5.0/8.0Gbps PCIe Passive Switches

10 ______________________________________________________________________________________

AIN+

AIN-

BIN+

BIN-

CIN+

CIN-

DIN+

DIN-

AOUTA+

AOUTA-

BOUTA+

BOUTA-

COUTA+

COUTA-

DOUTA+

DOUTA-

AOUTB+

AOUTB-

BOUTB+

BOUTB-

COUTB+

COUTB-

DOUTB+

DOUTB-

CHANNEL

SELECT

SEL

CHANNEL

SELECT

SEL

AIN+

AIN-

BIN+

BIN-

CIN+

CIN-

DIN+

DIN-

AOUTA+

AOUTA-

BOUTA+

BOUTA-

COUTA+

COUTA-

DOUTA+

DOUTA-

AOUTB+

AOUTB-

BOUTB+

BOUTB-

COUTB+

COUTB-

DOUTB+

DOUTB-

PCIe GRAPHICS

CONNECTOR 1

PCIe GRAPHICS

CONNECTOR 2

PCIe

NORTH BRIDGE

LANE 0 TX

LANE 1 TX

LANE 2 TX

LANE 3 TX

LANE 0 RX

LANE 1 RX

LANE 2 RX

LANE 3 RX

MAX4889B

VCC

GND

VCC

GND

Typical Operating Circuit: Video Graphics Cards

MAX4889B/MAX4889C

2.5/5.0/8.0Gbps PCIe Passive Switches

______________________________________________________________________________________ 11

Chip Information

PROCESS: CMOS

Package Information

For the latest package outline information and land patterns, go

to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in

the package code indicates RoHS status only. Package draw-

ings may show a different suffix character, but the drawing per-

tains to the package regardless of RoHS status.

PACKAGE

TYPE

PACKAGE

CODE

OUTLINE

NO.

LAND

PATTERN NO.

42 TQFN T423590M+1 21-0181 90-0079

MAX4889B/MAX4889C

2.5/5.0/8.0Gbps PCIe Passive Switches

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

2 8/10

Added 8.0Gbps PCIe passive switch to the title; added Gen III to the data rates in the

Features section; changed the return loss in the Features section to -10dB (typ) at

5.0GHz

All