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Alpha is a trademark of Digital Equipment Corporation. Pentium is a registered trademark of Intel Corporation. PowerPC is a trademark of IBM
Corporation.
www.fairchildsemi.com
Rev. 1.0.2
Features
Drives Two N-Channel MOSFETs
Operates from +5V Power Input
Simple Single-Loop Control Design
- Voltage-Mode PWM Control
Fast Transient Response
- High-Bandwidth Error Amplifier
- Full 0% to 100% Duty Ratio
Excellent Output Voltage Regulation
TTL Compatible 5 Bit Digital-to-Analog Output Voltage
Selection
- Wide Range - 1.3V
DC
to 3.5V
- 0.1V Binary Steps from 2.1V
- 0.05V Binary Steps from 1.3V
Power-Good Output Voltage Monitor
Over-Voltage and Over-Current Fault Monitors
- Does Not Require Extra Current Sensing Element, Uses
MOSFET’s R
DS(ON)
Small Converter Size
- Constant Frequency Operation
- 200kHz Free-Running Oscillator Programmable from
50kHz to 1MHz
DC
DC
DC
to 3.5V
to 2.1V
DC
DC
Applications
Power Supply for Pentium
and Alpha Microprocessors
High-Power 5V to 3.xV DC-DC Regulators
Low-Voltage Distributed Power Supplies
, Pentium Pro, PowerPC
Description
The RC5054A provides complete control and protection for
a DC-DC converter optimized for high-performance micro-
processor applications. It is designed to drive two N-Channel
MOSFETs in a synchronous-rectified buck topology. The
RC5054A integrates all of the control, output adjustment,
monitoring and protection functions into a single package.
The output voltage of the converter is easily adjusted and
precisely regulated. The RC5054A includes a 5-input digital-
to-analog converter (DAC) that adjusts the output voltage
from 2.1V
DC
to 3.5V
DC
in 0.1V increments and from
1.3V
DC
to 2.1V
DC
in 0.05V steps.
The RC5054A provides simple, single feedback loop, volt-
RC5054A
Programmable S ync hronous DC-DC Converter
Controller for Low Voltage Mic roproc essors
Block Diagram
D/A
CONVERTER
(DAC)
OSCILLATOR
SOFT-
REFERENCE
POWER-ON
RESET (POR)
115%
110%
90%
INHIBIT
PWM
COMPARATOR
EAMP
VCC
PGOOD
SS
PWM
OVP
RT
GND
VSEN
OCSET
VID0
VID1
VID2
VID3
VID4
FB
COMP
DACOUT
OVER-
VOLTAGE
OVER-
CURRENT
GATE
CONTROL
LOGIC
BOOT
UGATE
PHASE
200
μ
A
10
μ
A
4V
+
-
+
-
+
-
+
-
+
-
+
-
LGATE
PGND