VFM STEP-UP DC/DC

CONVERTER CONTROLLER

RN5RY202

NO.EA-042-0006

1

OUTLINE

The RN5RY202 Series are VFM (chopper) Control ICs for step-up DC/DC converter with an external power transis-

tor featuring high output voltage accuracy and low supply current by CMOS process. Each of the RN5RY202

Series ICs consists of a voltage reference unit, an error amplifier, an oscillator, a VFM control circuit and feed back

resistors.

Output voltage is fixed at 2V in the IC.

A low ripple, high efficiency step-up DC/DC converter can be constructed by simply adding an inductor, a diode, a

capacitor, and a drive transistor and feed back resistors.

Although the series have no CE pins unlike RN5RY

external feed back resistors.

FEATURES

• Low Supply Current............................................................................TYP. 3µA

• Low Temperature-Drift Coefficient of Output Voltage ...................TYP. ±50ppm/˚C

• High Accuracy Output Voltage .........................................................±2.5%

• Low Oscillation Start-up Voltage (no load) ......................................MAX. 0.8V

• Any output voltage can be set with external resistors

• Small Package SOT-23-5 (Mini-Mold)

APPLICATIONS

• Constant voltage power source for battery-powered instruments.

• Constant power source for cameras, camcorders, pagers, and other hand-held communication tools.

• Constant power source for devices that require higher voltages than battery voltages.

BLOCK DIAGRAM

+

–

2

3

1

5

Vref

Oscillator

Output

Buffer

GND

EXT