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www.fairchildsemi.com
Features
Programmable output from 1.3V to 3.5V
85% efficiency typical
1% output accuracy
Oscillator frequency adjustable from 80KHz to 1MHz
On-chip Power Good and Enable functions
Over-Voltage Protection
Foldback current limiting
Precision trimmed low TC voltage reference
20 pin SOIC package
Meets Intel Pentium
II specifications using minimum
number of external components
Applications
Programmable power supply for Pentium
Voltage Regulator Module (VRM) for Pentium II
processors
Programmable step-down power supply
II
Description
The RC5050 is a DC-DC controller IC which provides an
accurate, programmable output for all Pentium II CPU appli-
cations. The RC5050 uses a 5-bit D/A converter to program
the output voltage from 1.3V to 3.5V. The RC5050 uses a
high level of integration to deliver load currents in excess of
15A from a 5V source with minimal external circuitry. Non-
synchronous operation allows a low cost solution for most
CPU power supply applications. The internal oscillator can
be programmed from 80KHz to 1MHz for additional flexi-
bility in choosing external components. An on-board preci-
sion low TC reference achieves tight tolerance voltage
regulation without expensive external components. The
RC5050 also offers integrated functions including Power
Good, Output Enable, over-voltage protection and current
limiting.
Block Diagram
DIGITAL
CONTROL
–
+
1.24V
REFERENCE
5-BIT
DAC
65-5050-01
POWER
GOOD
OSC
PWRGD
VREF
VID0
VID1
VID2
VID4
VID3
ENABLE
–
+
–
+
–
+
+5V
VO
RC5050
+12V
RC5050
Programmable DC-DC Converter for Low Voltage
Mic roproc essors
Rev. 1.2.1
Pentium is a registered trademark of Intel Corporation.