April 2006
FAN5032
8-Bit Programmable 2 to 4 Phase Synchronous Buck
Controller
Features
Description
■ Selectable 2, 3, or 4 phase operation at up to 1MHz
The FAN5032 is a controller for a multi-phase buck
switching regulator optimized to convert a 12V input
supply to the processor core voltage required by high-
performance Intel processors. It has an internal 8-bit
digital to analog converter (DAC) that converts a digital
voltage identification (VID) code, sent from the processor
to set the output voltage between 0.5V and 1.6V in
6.25mV steps. It outputs a pulse-width modulated (PWM)
signal to external MOSFET drivers that, in turn, drive the
switching power MOSFETs. The switching frequency of
the design is programmable by a single resistor value
and the number of phases can be programmed to sup-
port 2, 3, or 4 phase applications.
per phase
■ ±7.7mV worst-case differential sensing error over
temperature
■ Active current balancing between the output phases
■ Power good and crowbar blanking supports on-the-fly
VID code changes
■ 0.5V to 1.6V output
®
■ Fully compliant to Intel VR10 and VR11
specifications
■ Selectable VR10 extended (7 bit) and VR11 (8 bit)
VID tables
■ Programmable soft-start ramp
The FAN5032 also includes programmable no-load off-
set and droop functions to adjust the output voltage as a
function of the load current, as required by the Intel spec-
ifications. The FAN5032 also provides an accurate and
reliable short-circuit protection function with an adjust-
able over-current set point.
■ Programmable short-circuit protection and latch-off
delay
Special Features
■ 300mV OVP and crowbar threshold
The FAN5032 is specified over the commercial tempera-
ture range of 0°C to 85°C and is available in a 40-lead
MLP package.
Applications
■ Desktop PC/server processor power supplies for
existing and next-generation Intel processors
■ VRM modules
Ordering Information
Product
Number
Operating
Package Type Pb-Free Temperature Range Packing Meathod
Quantity
per Reel
FAN5032MPX
MLP-40
Yes
0°C to 85°C
Tape and Reel
3,000
©2006 Fairchild Semiconductor Corporation
FAN5032 Rev. 1.0.0
1
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