5-Bit Programmable 2-/3-Phase
Synchronous Buck Controller
a
ADP3163
FEATURES
FUNCTIO NAL BLO CK D IAGRAM
ADOPT™ Optimal Positioning Technology for Superior
Load Transient Response and Fewest Output
Capacitors
Complies with VRM 9.0 and Intel VR Down Guideline
with Lowest System Cost
PC
VCC
ADP3163
SET
RESET
PWM1
PWM2
PWM3
UVLO
& BIAS
2-/3-PHASE
DRIVER
LOGIC
Digitally Selectable 2- or 3-Phase Operation
at up to 500 kHz per Phase
CROWBAR
Quad Logic-level PWM Outputs for Interface to
External High-Power Drivers
3.0V
REFERENCE
REF
PGND
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
GND
DAC+20%
OSCILLATOR
CT
POWER
GOOD
PWRGD
SHARE
CMP
Overvoltage Protection Crowbar Protects Microprocessors
with No Additional External Components
DAC+20%
CS–
CS+
FB
CMP
APPLICATIONS
Desktop PC Power Supplies for:
Intel Pentium® 4 Processors
AMD Athlon Processors
VRM Modules
g
COMP
m
SOFT
START
VID
DAC
VID4 VID3 VID2 VID1 VID0
GENERAL D ESCRIP TIO N
The ADP3163 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 ADP3163 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 ADP3163 is a highly efficient multiphase synchronous buck
switching regulator controller optimized for converting a 5 V or
12 V main supply into the core supply voltage required by high
performance Intel processors. The ADP3163 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 ADP3163 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 phase relationship of the output signals can be
programmed to provide 2- or 3-phase operation, allowing for
the construction of up to three complementary buck switching
stages. These stages share the dc output current to reduce
overall output voltage ripple. An active current balancing func-
tion ensures that all phases carry equal portions of the total load
current, even under large transient loads, to minimize the size of
the inductors.
The ADP3163 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.
REV. 0
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reliable. However, no responsibility is assumed by Analog Devices for its
use, norforanyinfringementsofpatentsorotherrightsofthirdpartiesthat
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
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© Analog Devices, Inc., 2001