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a
ADP3153
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700 World Wide Web Site: http://www.analog.com
Fax: 781/326-8703 © Analog Devices, Inc., 1998
5-Bit Programmable Dual
Power Supply Controller
for Pentium
®
II Processor
FEATURES
5-Bit Digitally Programmable 1.8 V to 3.5 V Output
Voltage
Dual N-Channel Synchronous Driver
Total Output Accuracy 61% (08C to +708C)
High Efficiency
Current-Mode Operation
Short Circuit Protection
Power Good Output
Overvoltage Protection Crowbar
On-Board Linear Regulator Controller
VRM 8.2 Compatible
Narrow Body TSSOP 20-Lead Package
APPLICATIONS
Desktop PC Power Supply for:
Pentium II Processor
Deschutes Processor
Pentium Pro Processor
Pentium Processor
AMD–K6 Processor
VRM Modules
GENERAL DESCRIPTION
The ADP3153 is a highly efficient synchronous switching regu-
lator controller and a linear regulator controller. The switching
regulator controller is optimized for Pentium II and Deschutes
Processor applications where 5 V is stepped down to a digitally
controlled output voltage between 1.8 V and 3.5 V. Using a 5-bit
DAC to read a voltage identification (VID) code directly from
the processor, the ADP3153 uses a current mode constant off-
time architecture to generate its precise output voltage.
The ADP3153 drives two N-channel MOSFETS in a synchro-
nous rectified buck converter, at a maximum switching fre-
quency of 250 kHz. Using the recommended loop compensation
and guidelines, the ADP3153 provides a dc/dc converter that
meets Intel’s stringent transient specifications with a minimum
number of output capacitors and smallest footprint. Addition-
ally, the current mode architecture also provides guaranteed
short circuit protection and adjustable current limiting.
The ADP3153’s linear regulator controller drives an external
N-channel device. The output voltage is set by the ratio of the
external feedback resistors. The controller has been designed for
excellent load transient response.
V
CC
+12V
1mF22mF
R1
R2
150pF
5-BIT CODE
IRL3103
V
IN
+5V
+
C
IN
10BQ015
L
2.5mH
IRL3103
+
C
O
V
O
1.8V–3.5V
14A
R
SENSE
7mV
1nF
C
COMP
V
CC
SD
DRIVE1
SENSE+
SENSE–
DRIVE2
PGND
VID0–VID4
AGND
C
T
CMP
ADP3153
35kV
FB
20kV
VLDO
V
IN
+5V
1000mF
V
O2
+3.3V
1A
IRL2703
Figure 1. Typical Application
Pentium is a registered trademark of Intel Corporation.
All other trademarks are the property of their respective holders.