POWER MANAGEMENT

1

www.semtech.com

SC2516

Complete Three-in-One DDR

Power Solution With BF_CUT

Features

Applications

Revision 8, May. 2005

Typical Application Circuit

Description

The SC2516 is a fully integrated, Three-in-One DDR Con-

troller supplying power to the VDDQ, VTT and GMCH

rails. Two synchronous buck controller provide the VDDQ

and GMCH at high efficiency, while an internal linear regu-

lator supplies the termination voltage with 1.8A(min)

Source/Sink capability.

signal to comply with motherboard state transitions. The

regulator uses the 5VDUAL rail to supply VDDQ under all

motherboard states, via the VDDQ switcher. The GMCH

regulator is slaved off the 5V main regulator, using a sepa-

rate UVLO on that rail. Additional logic and supervisory

circuitry complete the functionality of this single chip DDR

power solution in compliance with ACPI requirements.

The MLP package with a copper pad provides excellent

thermal impedance while keeping small footprint. VDDQ

short circuit protection along with VTT current limit as

well as two independent thermal shutdown circuits as-

sure safe operation under all fault conditions.

Power Solution for DDR memory per Intel

motherboard specification

High speed data line termination

Uses Latched BF_Cut from Intel Glue Chip to

control regulators

External VDDQ divider allows DDRI or DDRII Com-

patibility

High efficiency VDDQ switcher

External GMCH divider allows 1.5V or 1.25V pro-

gramming

High efficiency GMCH switcher supplies pro-

grammed output from the 5V or 3.3V rail

Single chip solution complies fully with ACPI power

sequencing specifications

1.8A (min) VTT Source/Sink capability

High current 1Amp gate driver for VDDQ switcher

Independent thermal shutdown for VTT

Fast transient response

Space saving 22-pin MLP package with copper

thermal pad for heatsinking to PC Board

VDDQ

3VCC

5VSBY

GMCH

VTT

12VCC

FB_GMCH

FBVDDQ

FBVDDQ

VDDQ

Latched BF_CUT

SC2516

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

COMP

FBVDDQ

SS/EN

VTTGND

VTT

VDDQ

AGND

VTTFB

REFSENS

FB_GMCH

SS_GMCH

POK

GND_GMCH

BG_GMCH

TG_GMCH

BF_CUT

COMP_GMCH

5VSBY

BST

TG

BG

PGND

ATXPWR_OK

VDDQ

FB_GMCH

5Vdual

SS/EN