OUTLINE

The RH5RI××1B/××2B/××3B Series are VFM (Chopper) Step-up DC/DC converter ICs with ultra low supply

current by CMOS process. The RH5RI××1B IC consists of an oscillator, a VFM control circuit, a driver transistor (Lx switch), a reference voltage unit, an error amplifier, resistors for voltage detection, and an Lx switch protection circuit. A low ripple, high efficiency step-up DC/DC converter can be constructed of this RH5RI××1B IC with only three external components, that is, an inductor, a diode and a capacitor.

FEATURES

• Small Number of External Components.......... Only an inductor, a diode and a capacitor (RH5RI××1B)

• Ultra Low Input Current................................... TYP. 4µA (RH5RI301B/303B at no load,with 1.5V input)

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

• Low Ripple and Low Noise

• Low Start-up Voltage (When the output current is 1mA)......................MAX. 0.9V

• High Efficiency...................................................TYP.80

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

• Small Packages................................................... SOT-89 (RH5RI××1B, RH5RI××2B)

SOT-89-5 (RH5RI××3B)

APPLICATIONS

• Power source for battery-powered equipment.

• Power source for cameras, camcorders, VCRs, PDAs, electronic data banks,and hand-held communication

equipment.

• Power source for appliances which require higher cell voltage than that of batteries used in the appliances.