White-LED Drivers Up Efficiency Ante

With an eye on battery life, the SiP12401 boost controller and SiP12501 boost converter drive white LEDs with efficiencies up to 80% and 75%, respectively. The SiP12401 relies on dual-cell NiMH, alkaline, or Li-ion batteries to drive LEDs connected in series without the need for ballast resistors. It supports input voltages from 1.8V to 5V. Powering LEDs connected in parallel, the SiP12501 employs single- or double-cell NiMH or alkaline battery packs. The device integrates a low-threshold power MOSFET that allows it to start up with a minimum voltage of 0.65V. Input voltages range from 0.65V to 3.3V and output current is up to 60 mA at 0.9V. Both drivers feature a voltage-mode PWM design with frequency compensation, 600-kHz switching frequency, and standby current specified at 1 µA. The SiP12401 and SiP12501 come in lead-free, six-pin PowerPAK MLP33 packages with price tags of $0.60 and $0.65 each/1,000, respectively. VISHAY INTERTECHNOLOGY INC., Malvern, Pa. (619) 336-0860.