FAN50FC3 Datasheet, PDF (1/21 Pages) Fairchild Semiconductor – 8-Bit Programmable, 2- to 3-Phase FastvCore™ Buck Controller

June 2007
FAN50FC3 — 8-Bit Programmable, 2- to 3-Phase
FastvCore™ Buck Controller
Features
ƒ FastvCore™ nonlinear control for fast transient and
to minimizes the number of output caps required
ƒ Selectable 2- or 3-phase operation at up to
1MHz per phase
ƒ ±7.7mV worst-case differential sensing error over
temperature
ƒ Active current balancing between output phases
ƒ Power Good and Crowbar blanking supports
on-the-fly VID code changes
ƒ 0.5V to 1.6V output
ƒ Usable for Intel^® VR10 and VR11 designs
ƒ Selectable VR10 extended (7-bit) and VR11 (8-bit)
VID tables
ƒ Programmable soft-start ramp
ƒ Programmable short-circuit protection and latch-off
delay
Applications
ƒ Desktop PC/Server processor power supplies for
existing and next-generation Intel^® processors
ƒ VRM modules
Related Applications Notes
ƒ AN-6052 — Instructions for the Multi-Phase VR11
MathCad^® Design Tool
Description
The FAN50FC3 device is a multi-phase buck switching
regulator controller optimized to convert a 12V input
supply to the processor core voltage required by high-
performance Intel^® processors. It has an internal, 8-bit
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
PWM signals to external MOSFET drivers that 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
support 2- or 3-phase applications.
The FAN50FC3 also includes programmable no-load
offset and droop functions to adjust the output voltage
as a function of the load current, as required by the
Intel^® specifications. The FAN50FC3 also provides an
accurate and reliable short-circuit protection function
with an adjustable over-current set point.
FastvCore™ technology greatly improves the fast
transient response required by today’s high-performance
processors. This allows fewer output capacitors to be
used in the application.
The FAN50FC3 is specified over the commercial
temperature range of 0°C to +85°C and is available in a
32-lead MLP package.
Ordering Information
Part Number Pb-Free
Operating
Temperature Range
FAN50FC3MPX Yes
0 to 85°C
Package
32-Lead, Molded Leadless
Package (MLP)
Packing Method
Tape and Reel
© 2007 Fairchild Semiconductor Corporation
FAN50FC3 Rev. 1.0.0
www.fairchildsemi.com