REV. 0

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under any patent or patent rights of Analog Devices.

a

ADP3164

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781/329-4700

www.analog.com

Fax: 781/326-8703

© Analog Devices, Inc., 2001

5-Bit Programmable 4-Phase

Synchronous Buck Controller

FUNCTIONAL BLOCK DIAGRAM

FEATURES

ADOPT™ Optimal Positioning Technology for Superior

Load Transient Response and Fewest Output

Capacitors

Complies with VRM 9.1 with Lowest System Cost

4-Phase Operation at up to 500 kHz per Phase

Quad Logic-Level PWM Outputs for Interface to

External High-Power Drivers

Active Current Balancing between All Output Phases

Accurate Multiple VRM Module Current Sharing

5-Bit Digitally Programmable 1.1 V to 1.85 V Output

Total Output Accuracy

0.8% Over Temperature

Current-Mode Operation

Short Circuit Protection

Enhanced Power Good Output Detects Open Outputs

in Multi-VRM Power Systems

Overvoltage Protection Crowbar Protects

Microprocessors with No Additional

External Components

APPLICATIONS

Desktop PC Power Supplies for:

VRM Modules

DAC + 20%

CMP

CS–

CS+

COMP

FB

PWM3

PWM1

SET

RESET

CROWBAR

PGND

PWM2

VID

DAC

VID4

VID3

VID2

VID1

VCC

REF

GND

CT

VID0

SHARE

POWER

GOOD

CMP

DAC – 20%

PWRGD

PWM4

3.0V

REFERENCE

UVLO

& BIAS

OSCILLATOR

4-PHASE

DRIVER

LOGIC

ADP3164

SOFT

START

GENERAL DESCRIPTION

The ADP3164 is a highly efficient 4-phase synchronous buck

switching regulator controller optimized for converting a 12 V

main supply into the core supply voltage required by high per-

formance Intel processors. The ADP3164 uses an internal 5-bit

DAC to read a voltage identification (VID) code directly from

the processor, which is used to set the output voltage between

1.1 V and 1.85 V. The ADP3164 uses a current mode PWM

architecture to drive the logic-level outputs at a programmable

switching frequency that can be optimized for VRM size and

efficiency. The four output phases share the dc output current

to reduce overall output voltage ripple. An active current bal-

ancing function ensures that all phases carry equal portions of

the total load current, even under large transient loads, to mini-

mize the size of the inductors.

The ADP3164 also uses a unique supplemental regulation tech-

nique called active voltage positioning (ADOPT) to enhance

load transient performance. Active voltage positioning results in

a dc/dc converter that meets the stringent output voltage specifi-

cations for high-performance processors, with the minimum

number of output capacitors and smallest footprint. Unlike

voltage-mode and standard current-mode architectures, active

voltage positioning adjusts the output voltage as a function of the

load current so that it is always optimally positioned for a system

transient. The ADP3164 also provides accurate and reliable short

circuit protection, adjustable current limiting, and an enhanced

Power Good output that can detect open outputs in any phase for

single or multi-VRM systems.

The ADP3164 is specified over the commercial temperature

range of 0

°C to 70°C and is available in a 20-lead TSSOP package.

ADOPT is a trademark of Analog Devices, Inc.

Pentium is a registered trademark of Intel Corporation.