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© Analog Devices, Inc., 2002

ADP3160/ADP3167

5-Bit Programmable 2-Phase

Synchronous Buck Controller

ADOPT is a trademark of Analog Devices, Inc.

Athlon is a trademark of Advanced Micro Devices, Inc.

Pentium is a registered trademark of Intel Corporation.

FEATURES

ADOPT™ Optimal Positioning Technology for Superior

Load Transient Response and Fewest Output Capacitors

Complies with VRM 9.0 with Lowest System Cost

Active Current Balancing between Both Output Phases

5-Bit Digitally Programmable 1.1 V to 1.85 V Output

Dual Logic-Level PWM Outputs for Interface to External

High Power Drivers

Total Output Accuracy

0.8% over Temperature

Current-Mode Operation

Short Circuit Protection

Power Good Output

Overvoltage Protection Crowbar Protects

Microprocessors with No Additional

External Components

APPLICATIONS

Desktop PC Power Supplies for:

Intel Pentium

AMD Athlon™ Processors

VRM Modules

GENERAL DESCRIPTION

The ADP3160 and ADP3167 are highly efficient, dual output,

synchronous buck switching regulator controllers optimized for

converting a 5 V or 12 V main supply into the core supply voltage

required by high-performance processors, such as Pentium 4 and

Athlon. The ADP3160 uses an internal 5-bit DAC to read a volt-

age identification (VID) code directly from the processor that is

used to set the output voltage between 1.1 V and 1.85 V. The

devices use a current-mode PWM architecture to drive two logic-

level outputs at a programmable switching frequency that can be

optimized for VRM size and efficiency. The output signals are

180 degrees out of phase, allowing for the construction of two

complementary buck switching stages. These two stages share the

dc output current to reduce overall output voltage ripple. An

active current balancing function ensures that both phases carry

equal portions of the total load current, even under large transient

loads, to minimize the size of the inductors. The ADP3160 control

FUNCTIONAL BLOCK DIAGRAM

2-PHASE

DRIVER

LOGIC

UVLO

AND

BIAS

3.0V

REFERENCE

OSCILLATOR

SET

RESET

CROWBAR

VCC

REF

GND

CT

COMP

PWM1

PWM2

PWRGD

CS–

CS+

FB

VID

DAC

VID4

VID3

VID2

VID1

VID0

CMP2

CMP1

DAC–18%

DAC+24%

ADP3160/ADP3167

CMP3

CMP

CMP

loop has been optimized for conversion from 12 V, while the

ADP3167 is designed for conversion from a 5 V supply.

The ADP3160 and ADP3167 also use a unique supplemental

regulation technique called active voltage positioning to enhance

load transient performance. Active voltage positioning results

in a dc/dc converter that meets the stringent output voltage

specifications 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. They also provide accurate and reliable short

circuit protection and adjustable current limiting.

The ADP3160 is specified over the commercial temperature

range of 0

∞C to 70∞C and is available in a 16-lead narrow body

SOIC package.