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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
Pentium VREF; 2% accuracy
>85% Efficiency
350uA quiescent current in shutdown
Fast transient response
Soft control power-up
Over-Voltage Protection
Factory trimmed low TC reference voltage
Adjustable oscillator frequency
Drives N-Channel MOSFETs; to 1 MHz
16 pin SOIC package
Applications
3.3V power supply for Pentium based CPUs requiring
2% VRE specification motherboards
Description
The RC5034 is a synchronous mode DC-DC controller IC
dedicated to providing a 5V to 3.52V conversion for
Pentium CPUs that require the 2% VRE voltage specifica-
tion. It can be configured in both the synchronous and non-
synchronous modes and with the proper applications cir-
cuitry can be used to deliver load current greater than 10
Amps. The RC5034 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. An integrated Over-Voltage protection function
constantly monitors the output voltage and shuts down the
power to the CPU in the event of a out-of-tolerance voltage
situation, thereby protecting the CPU. 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
65-5034-01
OSC
VREF
–
+
+
–
I
–
+
+
–
I
–
+
+
–
I
VIN
VO
RC5034
High Ac c urac y S ync hronous DC-DC Converter
Rev. 0.9.6