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ISL6548

ACPI Regulator/Controller for

Dual Channel DDR Memory Systems

The ISL6548 provides a complete ACPI compliant power

solution for up to 4 DIMM dual channel DDR/DDR2 Memory

systems. Included are both a synchronous buck controller to

state, a fully integrated sink-source regulator generates an

need for a negative supply. Two LDO controllers are also

integrated for the GMCH core voltage regulation and for the

The switching PWM controller drives two N-Channel

MOSFETs in a synchronous-rectified buck converter

topology. The synchronous buck converter uses voltage-

mode control with fast transient response. The switching

regulator provides a maximum static regulation tolerance of

±

2% over line, load, and temperature ranges. The output is

user-adjustable by means of external resistors down to 0.8V.

An integrated soft-start feature brings all outputs into

regulation in a controlled manner when returning to S0/S1

state from any sleep state. During S0 the VIDPGD signal

within spec and operational.

Each output is monitored for undervoltage events. The

switching regulator also has overvoltage and overcurrent

protection. Thermal shutdown is integrated.

Pinout

ISL6548 (6x6 QFN)

TOP VIEW

Features

• Generates 4 Regulated Voltages

- 3A Integrated Sink/Source Linear Regulator with

- LDO Regulator for GMCH Core

Termination

• ACPI Compliant Sleep State Control

• Glitch-free Transitions During State Changes

• PWM Controller Drives Low Cost N-Channel MOSFETs

• 250kHz Constant Frequency Operation

• Tight Output Voltage Regulation

• Fully-Adjustable Outputs with Wide Voltage Range: Down

to 0.8V supports DDR and DDR2 Specifications

• Simple Single-Loop Voltage-Mode PWM Control Design

• Fast PWM Converter Transient Response

• Under and Overvoltage Monitoring on All Outputs

• OCP on the Switching Regulator

• Integrated Thermal Shutdown Protection

• Pb-Free Plus Anneal Available (RoHS Compliant)

Applications

• Single and Dual Channel DDR Memory Power Systems in

ACPI compliant PCs

• Graphics Cards - GPU and Memory Supplies

• ASIC Power Supplies

• Embedded Processor and I/O Supplies

• DSP Supplies

1

2

3

4

5

6

7

21

20

19

18

17

16

15

28

27

26

25

24

23

22

8

9

10

11

12

13

14

DRIVE4

REFADJ4

DRIVE3

FB3

FB4

COMP

FB

5VSBY

S3#

P12V

GND

DDR_VTT

DDR_VTT

VDDQ

GND

29

Ordering Information

PART NUMBER

PART

MARKING

TEMP.

RANGE

(°C)

PACKAGE

PKG.

DWG. #

ISL6548CRZA

(Note)

ISL6548CRZ

0 to 70

28 Ld 6x6 QFN

(Pb-free)

L28.6x6

ISL6548CRZA-T

(Note)

ISL6548CRZ

0 to 70

28 Ld 6x6 QFN

Tape and Reel

(Pb-free)

L28.6x6

NOTE: Intersil Pb-free plus anneal products employ special Pb-free

material sets; molding compounds/die attach materials and 100% matte

tin plate termination finish, which are RoHS compliant and compatible

with both SnPb and Pb-free soldering operations. Intersil Pb-free

products are MSL classified at Pb-free peak reflow temperatures that

meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.

Data Sheet

FN9188.2

January 3, 2006