MAX4952BCTP+T Maxim Integrated, MAX4952BCTP+T Datasheet - Page 9

• Manufacturer Part Number: MAX4952BCTP+T
• Description: Buffers & Line Drivers SINGALE LANE SAS RE-DRIVER
• Manufacturer: Maxim Integrated

Specifications of MAX4952BCTP+T

• Number Of Input Lines: 2
• Number Of Output Lines: 2
• Polarity: Non-Inverting
• Supply Voltage - Max: 3 V
• Supply Voltage - Min: 3.6 V
• Data Rate: 6 Gbps

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.
Inputs and outputs are internally 50I terminated to V
(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.
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.
The MAX4952B supports both SAS and SATA OOB levels.
When in SAS mode, the OOB threshold is 120mV
and when in SATA mode, the OOB threshold is 50mV
(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).
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.
Circuit board layout and design can significantly affect
the performance of the MAX4952B. Use good, high-fre-
Output Boost-Selection Inputs (BA, BB)
Enable Input (EN)/Power-Down Mode
Applications Information
_______________________________________________________________________________________
Dual 1.5/3.0/6.0Gbps SAS/SATA Redriver
Detailed Description
Input/Output Terminations
SAS/SATA Mode Input (M)
P-P
Layout
(min),
P-P
CC
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 V
V
MAX4952B requires coupling capacitors for all redriver
inputs and outputs. Maxim recommends high-quality,
low-ESR, X7R, 10nF, 0402-sized capacitors.
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.
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.
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.
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 V
ing signals, especially if the signal is not current limited.
CC
pin. Always connect V
CC
as possible, or, as recommended, on each
Power-Supply Sequencing
Exposed-Pad Package
CC
Human Body Model
to a power plane. The
ESD Protection
CC
before apply-
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