_______________________________________________________________ Maxim Integrated Products 1
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.
MAX4952B
Dual 1.5/3.0/6.0Gbps SAS/SATA Redriver
19-5126; Rev 0; 1/10
General Description
The MAX4952B dual-channel redriver is designed to
redrive one full lane of SAS or SATA signals up to
6.0Gbps and operates from a single +3.3V supply.
The MAX4952B is designed for commercial SAS or
SAS/SATA applications, such as servers.
The MAX4952B features independent output boost and
enhances signal integrity at the receiver by re-establishing
full output levels. SAS/SATA out-of-band (OOB) signaling
is supported using high-speed amplitude detection on
the inputs and squelch on the corresponding outputs.
Inputs and outputs are all terminated in 50I internally
and exhibit excellent return loss.
The MAX4952B is available in a small, 20-pin, 4.0mm x
4.0mm TQFN package with flow-through traces for ease
of layout. This device is specified over the 0NC to +70NC
operating temperature range.
Applications
Servers
Data Storage
Features
S Single +3.3V Supply Operation
S Low Power-Down Current (350µA typ) for Power-
Sensitive Applications
S Supports SAS I/II/III P 6.0Gbps
S Excellent Return Loss
Exceeds SAS/SATA Return Loss Mask (Better
Than 8dB Up to 3GHz)
S Supports SAS/SATA OOB-Level Signaling
Very Fast Entry and Exit Time of 5ns (Max)
Programmable SAS/SATA Threshold
S Independent Output-Boost Selection
Two Levels: 0dB, 6dB
S On-Chip 50I Input/Output Terminations
S In-Line Signal Traces for Flow-Through Layout
S Space-Saving, 4.0mm x 4.0mm TQFN Package
S ESD Protection on All Pins: ±5.5kV (Human Body
Model)
Ordering Information
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed Pad.
EVALUATION KIT
AVAILABLE
PART TEMP RANGE PIN-PACKAGE
MAX4952BCTP+ 0NC to +70NC20 TQFN-EP*
2 ______________________________________________________________________________________
MAX4952B
Dual 1.5/3.0/6.0Gbps SAS/SATA Redriver
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.)
VCC .......................................................................-0.3V to +4.0V
All Other Pins (Note 1) ............................. -0.3V to (VCC + 0.3V)
Short-Circuit Output Current DAP, DAM, HBM, HBP .........90mA
Continuous Power Dissipation (TA = +70NC)
20-Pin TQFN (derate 25.6mW/NC above +70NC) .......2051mW
Junction-to-Case Thermal Resistance (BJC) (Note 2)
20-Pin TQFN ...................................................................6NC/W
Junction-to-Ambient Thermal Resistance (BJA) (Note 2)
20-Pin TQFN .................................................................39NC/W
Operating Temperature Range ............................. 0NC to +70NC
Junction Temperature .....................................................+150NC
Storage Temperature Range ............................ -55NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
ELECTRICAL CHARACTERISTICS
(VCC = +3.0V to +3.6V, CCL = 10nF coupling capacitor on each output, RL = 50I on each output, TA = 0NC to +70NC, unless other-
wise noted. Typical values are at VCC = +3.3V and TA = +25NC.) (Note 3)
ABSOLUTE MAXIMUM RATINGS
Note 1: All I/O pins are clamped by internal diodes.
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.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
DC PERFORMANCE
Power-Supply Range VCC 3.0 3.6 V
Power-Down Current IPWRDN EN = GND 0.35 2 mA
Supply Current ICC EN = VCC BA = BB = VCC 100 130 mA
BA = BB = GND 85 100
Input Impedance, Differential ZRX-DIFF-
DC DC 85 100 115 I
Output Impedance, Differential ZTX-DIFF-
DC DC 85 100 115 I
AC PERFORMANCE
Input Return Loss, Differential
(Note 4) RLRX-DIFF
0.1GHz < f P 0.3GHz -18
dB
0.3GHz < f P 0.6GHz -14
0.6GHz < f P 1.2GHz -10
1.2GHz < f P 2.4GHz -8
2.4GHz < f P 3.0GHz -8
3.0GHz < f P 6.0GHz -1
Input Return Loss,
Common Mode (Note 4) RLRX-CM
0.1GHz < f P 0.3GHz -6
dB
0.3GHz < f P 0.6GHz -5
0.6GHz < f P 1.2GHz -5
1.2GHz < f P 2.4GHz -5
2.4GHz < f P 3.0GHz -5
3.0GHz < f P 6.0GHz -1
_______________________________________________________________________________________ 3
MAX4952B
Dual 1.5/3.0/6.0Gbps SAS/SATA Redriver
Note 3: This device is 100% production tested at TA = +70°C. Specifications for all temperature limits are guaranteed by design.
Note 4: Guaranteed by design.
Note 5: Rise and fall times are measured using 20% and 80% levels.
Note 6: DJ measured using K28.5 pattern; RJ measured using D10.2 pattern.
Note 7: Total time for OOB detection circuit to enable/squelch the output.
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3.0V to +3.6V, CCL = 10nF coupling capacitor on each output, RL = 50I on each output, TA = 0NC to +70NC, unless other-
wise noted. Typical values are at VCC = +3.3V and TA = +25NC.) (Note 3)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Output Return Loss, Differential
(Note 4) RLTX-DIFF
0.1GHz < f P 0.3GHz -14
dB
0.3GHz < f P 0.6GHz -8
0.6GHz < f P 1.2GHz -8
1.2GHz < f P 2.4GHz -8
2.4GHz < f P 3.0GHz -8
3.0GHz < f P 6.0GHz -1
Output Return Loss,
Common Mode (Note 4) RLTX-CM
0.1GHz < f P 0.3GHz -8
dB
0.3GHz < f P 0.6GHz -5
0.6GHz < f P 1.2GHz -5
1.2GHz < f P 2.4GHz -5
2.4GHz < f P 3.0GHz -5
3.0GHz < f P 6.0GHz -1
Differential Input Signal Range VRX-DFF-PP
SATA 1.5Gbps, 3Gbps, 6Gbps, M = GND 225 1600
mVP-P
SAS 1.5Gbps, 3Gbps, M = VCC 275 1600
SAS 6.0Gbps, M = VCC 300 1600
OOB Squelch Threshold VSQ-DIFF SATA OOB, M = GND 50 150 mVP-P
SAS OOB, M = VCC 120 220
Differential Output-Voltage
Swing VTX-DIFF-PP f = 750MHz, 1.5GHz BA = BB = GND 450 650 mVP-P
BA = BB = VCC 900 1300
Propagation Delay tPD 300 ps
Output Rise/Fall Time tTX-RISE-
FALL Figure 1 (Notes 4, 5) 40 40 ps
Deterministic Jitter tTX-DJ-DD Up to 6.0Gbps (Notes 4, 6) 15 psP-P
Random Jitter tTX-RJ-DD Up to 6.0Gbps (Notes 4, 6) 1.4 psRMS
OOB Output Startup/Shutdown
Time tOOB (Note 7) 3 5 ns
Differential Offset Delta DVOOB,DIFF Difference between OOB and active-mode
output offset -80 +80 mV
Common-Mode Delta DVOOB,CM Difference between OOB and active-mode
output VCM -50 +50 mV
CONTROL LOGIC
Input Logic-Level Low VIL 0.6 V
Input Logic-Level High VIH 1.4 V
Input Logic Hysteresis VHYST 100 mV
Input Pulldown Resistor RDOWN 70 kI
ESD PROTECTION
All Pins Human Body Model ±5.5 kV
4 ______________________________________________________________________________________
MAX4952B
Dual 1.5/3.0/6.0Gbps SAS/SATA Redriver
Typical Operating Characteristics
(VCC = +3.3V, M = GND, TA = +25NC; all eye diagrams measured using K28.5 pattern, unless otherwise noted.)
VIN = 1600mVP-P, 6Gbps, B_ = 0
50ps/div
100mV/div
10050-100 -50 0
-300
-200
-100
0
100
200
300
400
-400
-150 150
MAX4952B toc09
VIN = 1600mVP-P, 3Gbps, B_ = 0
100ps/div
100mV/div
200100-200 -100 0
-300
-200
-100
0
100
200
300
400
-400
-300 300
MAX4952B toc08
VIN = 1600mVP-P, 1.5Gbps, B_ = 0
200ps/div
100mV/div
400200-400 -200 0
-300
-200
-100
0
100
200
300
400
-400
-600 600
MAX4952B toc07
VIN = 225mVP-P, 6Gbps, B_ = 1
50ps/div
200mV/div
10050-100 -50 0
-600
-400
-200
0
200
400
600
-150 150
MAX4952B toc06
VIN = 225mVP-P, 3Gbps, B_ = 1
100ps/div
200mV/div
200100-200 -100 0
-600
-400
-200
0
200
400
600
-300 300
MAX4952B toc05
VIN = 225mVP-P, 1.5Gbps, B_ = 1
200ps/div
200mV/div
400200-400 -200 0
-600
-400
-200
0
200
400
600
-600 600
MAX4952B toc04
VIN = 225mVP-P, 6Gbps, B_ = 0
50ps/div
100mV/div
10050-100 -50 0
-300
-200
-100
0
100
200
300
400
-400
-150 150
MAX4952B toc03
VIN = 225mVP-P, 3Gbps, B_ = 0
100ps/div
100mV/div
200100-200 -100 0
-300
-200
-100
0
100
200
300
400
-400
-300 300
MAX4952B toc02
VIN = 225mVP-P, 1.5Gbps, B_ = 0
200ps/div
100mV/div
400200-400 -200 0
-300
-200
-100
0
100
200
300
400
-400
-600 600
MAX4952B toc01
_______________________________________________________________________________________ 5
MAX4952B
Dual 1.5/3.0/6.0Gbps SAS/SATA Redriver
Typical Operating Characteristics (continued)
(VCC = +3.3V, M = GND, TA = +25NC; all eye diagrams measured using K28.5 pattern, unless otherwise noted.)
DIFFERENTIAL OUTPUT RETURN LOSS
vs. FREQUENCY
MAX4952B toc14
FREQUENCY (GHz)
DIFFERENTIAL OUTPUT RETURN LOSS (dB)
42
-35
-30
-25
-20
-15
-10
-5
0
-40
0 6
EC TABLE LIMIT
MAX4952B
DIFFERENTIAL INPUT RETURN LOSS
vs. FREQUENCY
MAX4952B toc13
FREQUENCY (GHz)
DIFFERENTIAL INPUT RETURN LOSS (dB)
42
-35
-30
-25
-20
-15
-10
-5
0
-40
0 6
EC TABLE LIMIT
MAX4952B
VIN = 1600mVP-P, 6Gbps, B_ = 1
50ps/div
200mV/div
10050-100 -50 0
-600
-400
-200
0
200
400
600
-150 150
MAX4952B toc12
VIN = 1600mVP-P, 3Gbps, B_ = 1
100ps/div
200mV/div
200100-200 -100 0
-600
-400
-200
0
200
400
600
-300 300
MAX4952B toc11
VIN = 1600mVP-P, 1.5Gbps, B_ = 1
200ps/div
200mV/div
400200-400 -200 0
-600
-400
-200
0
200
400
600
-600 600
MAX4952B toc10
6 ______________________________________________________________________________________
MAX4952B
Dual 1.5/3.0/6.0Gbps SAS/SATA Redriver
Pin Description
Note: For proper operation, Maxim recommends the use of low-ESR, X7R, 10nF, 0402-sized capacitors for all redriver inputs and
outputs.
Pin Configuration
19
20
18
17
7
6
8
HAM
HBP
9
HAP
DAM
DBM
DBP
DAP
1 2
GND
4 5
15 14 12 11
M
*EP
*CONNECT EXPOSED PAD (EP) TO GND.
VCC
BA
BB
EN
VCC
GND GND
3
13
GND
16 10 VCC
VCC
+
TQFN
TOP VIEW
HBM
MAX4952B
PIN NAME FUNCTION
1 HAP Noninverting Input from Host Channel A. HAP must be capacitively coupled (see note).
2 HAM Inverting Input from Host Channel A. HAM must be capacitively coupled (see note).
3, 13, 17, 18 GND Ground
4 HBM Inverting Output to Host Channel B. HBM must be capacitively coupled (see note).
5 HBP Noninverting Output to Host Channel B. HBP must be capacitively coupled (see note).
6, 10, 16, 20 VCC Power-Supply Input. Bypass VCC to GND with low-ESR 0.01FF and 4.7FF capacitors in parallel as
close to the device as possible; recommended for each VCC pin.
7 EN Enable Input. Drive EN low for low-power standby mode. Drive EN high for normal operation. EN is
internally pulled down by a 70kI (typ) resistor.
8 BB Channel B Boost-Enable Input. Drive BB high to enable channel B +6dB output boost. Drive BB low
for standard SAS/SATA output level. BB is internally pulled down by a 70kI (typ) resistor.
9 BA Channel A Boost-Enable Input. Drive BA high to enable channel A +6dB output boost. Drive BA low
for standard SAS/SATA output level. BA is internally pulled down by a 70kI (typ) resistor.
11 DBP Noninverting Input from Device Channel B. DBP must be capacitively coupled (see note).
12 DBM Inverting Input from Device Channel B. DBM must be capacitively coupled (see note).
14 DAM Inverting Output to Device Channel A. DAM must be capacitively coupled (see note).
15 DAP Noninverting Output to Device Channel A. DAP must be capacatively coupled (see note).
19 M OOB-Mode Logic Input. M is internally pulled down by a 70kI (typ) resistor. Drive M low or leave
unconnected for SATA OOB threshold. Drive M high for SAS OOB threshold.
— EP Exposed Pad. Internally connected to GND. Connect to a large ground plane for proper thermal
and electrical operation. Not intended as an electrical connection point.
_______________________________________________________________________________________ 7
MAX4952B
Dual 1.5/3.0/6.0Gbps SAS/SATA Redriver
Functional Diagram/Truth Table
X = Don’t care.
Figure 1. Circuit for Measuring tR/F for MAX4952B (refer to the SATA specifications for compliance measurement)
MAX4952B
50Ω50Ω
VCC
VCC
50Ω50Ω
VCC
DAP
DAM
HAP
HAM
50Ω50Ω
VCC
50Ω50Ω
VCC
DBM
DBP
HBM
HBP
CONTROL LOGIC
ENGND M BA BB
RISE/FALL TIME
COMPLIANCE POINT
CONTROLLED
IMPEDANCE
eSATA CONNECTOR
2in (5cm) MINIMUM
MAX4952B
EN BA BB CHANNEL A
OUTPUT LEVEL
CHANNEL B
OUTPUT LEVEL
0 X X Power-Down Power-Down
1 0 0 No Boost No Boost
1 0 1 No Boost Boost
1 1 0 Boost No Boost
1 1 1 Boost Boost
M OOB THRESHOLD
0 SATA
1 SAS
8 ______________________________________________________________________________________
MAX4952B
Dual 1.5/3.0/6.0Gbps SAS/SATA Redriver
Figure 2. Typical Application Circuit
Figure 3. MAX4952B Driving a SAS Cable
MAX4952B
EN M BA
GPIO GPIO
BB GND
VCC
4.7μF 0.01μF
HAP DAP
10nF (X7R) 10nF (X7R)
HAM DAM
10nF (X7R) 10nF (X7R)
HBM DBM
10nF (X7R)
HBP DBP
10nF (X7R)
10nF (X7R) 10nF (X7R)
Rx
Tx
Tx
SAS HOST
CONTROLLER
Rx
SAS DEVICE
CONNECTOR
+3.3V
MAX4952B
BACKPLANE
SAS/SATA HDD
MIDPLANE
SAS CABLE
MAIN BOARD
SAS
CONTROLLER
8in BOARD
TRACES
8in BOARD
TRACES
_______________________________________________________________________________________ 9
MAX4952B
Dual 1.5/3.0/6.0Gbps SAS/SATA Redriver
Detailed Description
The MAX4952B dual-channel redriver is designed to
redrive one full lane of SAS/SATA signals up to 6.0Gbps
while operating from a single +3.3V supply.
The MAX4952B features independent output boost and
enhances signal integrity at the receiver by re-estab-
lishing full output levels. SAS/SATA OOB signaling is
supported using high-speed amplitude detection on the
inputs and squelch on the corresponding outputs.
Input/Output Terminations
Inputs and outputs are internally 50I terminated to VCC
(see the Functional Diagram/Truth Table) and must be
AC-coupled using low-ESR, X7R, 10nF capacitors to the
SAS/SATA controller IC and SAS/SATA device for proper
operation.
Enable Input (EN)/Power-Down Mode
The MAX4952B features an active-high enable input,
EN, which has an internal pulldown resistor of 70kI
(typ). When EN is driven low or left unconnected, the
MAX4952B enters power-down mode and squelches the
output. Drive EN high for normal operation.
SAS/SATA Mode Input (M)
The MAX4952B supports both SAS and SATA OOB levels.
When in SAS mode, the OOB threshold is 120mVP-P (min),
and when in SATA mode, the OOB threshold is 50mVP-P
(min). Signals below the OOB threshold are squelched
to prevent unwanted noise from being redriven at the
output. Drive M low or leave unconnected to set SATA
OOB levels. Drive M high to set SAS OOB levels. See
the Functional Diagram/Truth Table. M has an internal
pulldown resistor of 70kI (typ).
Output Boost-Selection Inputs (BA, BB)
The MAX4952B has two digital control logic inputs, BA
and BB. BA and BB have internal pulldown resistors of
70kI (typ). BA and BB control the boost level of their
corresponding redrivers (see the Functional Diagram/
Truth Table). Drive BA or BB low or leave unconnected
for standard SAS/SATA output levels. Drive BA or BB
high to boost the output.
Applications Information
Layout
Circuit board layout and design can significantly affect
the performance of the MAX4952B. Use good, high-fre-
quency design techniques, including minimizing ground
inductance and using controlled-impedance transmis-
sion lines on data signals. Place low-ESR 0.01FF and
4.7FF power-supply bypass capacitors in parallel as
close to VCC as possible, or, as recommended, on each
VCC pin. Always connect VCC to a power plane. The
MAX4952B requires coupling capacitors for all redriver
inputs and outputs. Maxim recommends high-quality,
low-ESR, X7R, 10nF, 0402-sized capacitors.
Exposed-Pad Package
The exposed-pad, 20-pin TQFN package incorporates
features that provide a very low-thermal resistance
path for heat removal from the IC. The exposed pad on
the MAX4952B must be soldered to the circuit board
ground plane for proper thermal and electrical perfor-
mance. For more information on exposed-pad pack-
ages, refer to Application Note 862: HFAN-08.1: Thermal
Considerations of QFN and Other Exposed-Paddle
Packages.
ESD Protection
As with all Maxim devices, ESD protection structures are
incorporated on all pins to protect against electrostatic
discharges encountered during handling and assembly.
The MAX4952B is protected against ESD up to Q5.5kV
(Human Body Model) without damage. The ESD struc-
tures withstand Q5.5kV in all states (normal operation
and powered down). After an ESD event, the MAX4952B
continues to function without latchup.
Human Body Model
The MAX4952B is characterized for Q5.5kV ESD pro-
tection using the Human Body Model (MIL-STD-883,
Method 3015). Figure 4 shows the Human Body Model
and Figure 5 shows the current waveform it generates
when discharged into low impedance. This model con-
sists of a 100pF capacitor charged to the ESD voltage of
interest that is then discharged into the device through
a 1.5kI resistor.
Power-Supply Sequencing
Caution: Do not exceed the absolute maximum
ratings because stresses beyond the listed ratings
can cause permanent damage to the device.
Proper power-supply sequencing is recommended for
all devices. Always apply GND then VCC before apply-
ing signals, especially if the signal is not current limited.
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.
10 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX4952B
Dual 1.5/3.0/6.0Gbps SAS/SATA Redriver
Chip Information
PROCESS: BiCMOS
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
drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
Figure 4. Human Body ESD Test Model Figure 5. Human Body Current Waveform
CHARGE-CURRENT
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
CS
100pF
RC
1MΩ
RD
1500Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
IP 100%
90%
36.8%
tRL TIME
tDL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Ir
10%
0
0
AMPS
PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
20 TQFN-EP T2044+2 21-0139
