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SC2596

PRELIMINARY

POWER MANAGEMENT

Block Diagram

+

-

Error Am p.

AVCC

GND

UVLO +

Thermal

Shutdown

VDDQ

Vsense

VTT

Anti-

Shoot-

thru

+

Driver

Circuit

PVCC

EN

VREF

Vref Buffer

Description

Description

Description

Description

Description

SC2596 is a low-voltage, low-dropout DDR termination

regulator with separate power supply to support both

DDR1 and DDR2 applications. AVCC and PVCC can be

tied together for DDR1 and can also be separated for

DDR2.

SC2596 regulates VTT to the voltage of VREF. VTT will

sink or source upto 2.5A. Internal shoot-through protec-

tion ensure both top and bottom MOSFET will not con-

duct while maintaining fast source-to-sink load transient.

Thermal shut-down and internal current limit protect

SC2596 from shorted load or over-heated

VREF BUFF

VREF BUFF

VREF BUFF

VREF BUFF

VREF BUFF

VREF is derived from VDDQ with an accurate divide by

op-amps(VREF Buffer). It is capable to sink and source

30uA. It is used as the reference voltage to the Error

amp. A 100nF or higher capacitor is recommended for

VREF pin to ground; To enhance the noise immunity from

board, an additional pull-down resistor (1M

Ω) is

recomanded as well from VREF pin to ground.

ERROR AMP

ERROR AMP

ERROR AMP

ERROR AMP

ERROR AMP

Low input offset op-amp for the main linear regulator. It

controls the VTT output voltage and which side of the

MOSFET to turn on (or turn off) to achieve zero shoot

through current.

ANTI-Shoot Thought Driver

ANTI-Shoot Thought Driver

ANTI-Shoot Thought Driver

ANTI-Shoot Thought Driver

ANTI-Shoot Thought Driver

Buffer stage takes the error voltage to control MOSFET.

Internal current limit is incorporated to protect from

shorted load.

THERMAL SHUTDOWN & UVLO

THERMAL SHUTDOWN & UVLO

THERMAL SHUTDOWN & UVLO

THERMAL SHUTDOWN & UVLO

THERMAL SHUTDOWN & UVLO

The Thermal shutdown block prevent the junction tem-

power is available for correct operation of the IC.