Off-Line Battery Charger Chip Has Wide Operating Range

The VIPer12A off-line battery charger integrates a dedicated current-mode PWM control circuit with an on-chip, high-voltage power MOSFET making a compact solution for off-line battery charger applications from 1W to 10W (1W to 5W for wide-range 115-230V input). The control circuit accepts a wide range of auxiliary supply voltages from 8V to 40V, and there is even an automatic under-voltage lockout, with hysteresis. The chip uses current feedback, which is compared to a sense current provided by the special structure of the output MOSFET. Current-mode control is ideal for opto-isolated feedback, which provides maximum flexibility in circuit configuration. Typical applications include dual voltage and current control for Li-ion batteries, and feed-forward conversion, where the wide operating voltage range minimizes the size of the auxiliary capacitor, and dramatically reduces start-up time. The control circuit includes built-in over-voltage, under-voltage and over-temperature protection, and the 50 kHz devices are rated up to 730V VDSS. The VIPer12A is available at $0.74 each/1,000 for the DIP8 package and $0.67 for SO8 package. STMICROELECTRONICS INC., Lexington, MA. (781) 861-2650.