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PRELIMINARY INFORMATION
describes products that are not in full production at the time of printing. Specifications are based on design goals
and limited characterization. They may change without notice. Contact Fairchild Semiconductor for current information.
P
www.fairchildsemi.com
Features
>85% Efficiency
Fast transient response
Soft control power-up
Short circuit protection
Output voltage fixed 3.3V
Low TC reference voltage
Adjustable oscillator frequency
Drives N-Channel MOSFET
8 pin SOIC, 8 pin DIP package
Applications
3.3V power supply for Pentium based desktop CPU
motherboards
Minimum component DC-DC converters
Description
The RC5032 is a step-down DC-DC controller IC dedicated
to providing a 5V to 3.3V conversion for various types of
CPU power. It can be configured with the proper applications
circuitry to deliver load currents greater than 10 Amps. The
RC5032 is designed to operate in a standard PWM control
mode under heavy load conditions and as a PFM controller
in light load conditions. Its highly accurate low TC reference
eliminates the need for precision external components in
order to achieve tight tolerance voltage regulation.
The programmable oscillator can operate from 200KHz to
greater than 1MHz to provide for flexibility in choosing
external components such as inductors, capacitors, and
Power MOSFETs.
Block Diagram
DIGITAL
CONTROL
–
+
+
–
I
VREF
65-5032-01
OSC
–
+
+
–
I
–
+
+
–
I
–
+
+
–
I
VIN
+12V
VO
RC5032
5V to 3.3V S tep-Down DC-DC Converter
Rev. 0.9.6