RT9261

Preliminary RT9261/A VFM Step-up DC/DC Converter General Description The RT9261 Series are VFM Step-up DC/DC ICs with ultra low supply current by CMOS process and suitable for use with battery-powered instruments. The RT9261 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 a LX switch protection circuit. A low ripple and high efficiency step-up DC/DC converter can be constructed of this RT9261 IC with only three external components. The RT9261A IC provides with a drive pin (EXT) for an external transistor, so that a power transistor can be externally applied. Therefore, the RT9261A IC is recommended for applications where large currents are required. CE pin enables circuit to set the standby supply current at a maximum of 0.5µA. Features Minimal Number of External Components ( Only an Inductor, a Diode, and a Capacitor) Ultra Low Input Current ( 5µA at Switch Off) ± 2% High Output Voltage Accuracy Low Ripple and Low Noise Low Start-up Voltage, 0.85V at 1mA 75% Efficiency with Low Cost Inductor +50 ppm/ °C Low Temperature-Drift SOT-89 and SOT-25 Small Packages Applications Power source for battery-powered equipment Power source for cameras, camcorders, VCRs, PDAs, pagers, electronic data banks, and hand-held communication equipment Power source for applications, which require higher voltage than that of batteries used in the appliances Ordering Informati...