MAX4952BCTP 데이터 시트보기 (PDF) - Maxim Integrated

부품명

상세내역

제조사

MAX4952BCTP

Dual 1.5/3.0/6.0Gbps SAS/SATA Redriver

Maxim Integrated 

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 SATA output levels. Drive BA or BB high to

boost the output or for standard SAS output levels.

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.

_______________________________________________________________________________________   9

Share Link: