1.2-MHz Boost Converter Operates From A Single Cell

Delivering up to 150 mA of output current at 3.3V, the AS1322 synchronous, step-up dc/dc converter in a 6-pin TSOT package derives power from a single AA cell and provides output voltages from 2.5 to 5V from an input voltage between 0.85V and 5.5V. The device's 1.2-MHz switching frequency minimizes PCB space by allowing the use of low-profile inductors and ceramic capacitors. It is available in two versions: the lower-power AS1322A and fixed frequency AS1322B. The AS1322A offers an automatic power-save function in cases of light loads, reducing consumption down to 30 µA. Anti-ringing circuitry reduces EMI by damping the inductor in discontinuous mode. The AS1322B maintains fixed-frequency operation at lighter loads, making it suitable for applications requiring predictable and easy to filter output noise, i.e., mobile communications. AUSTRIAMICROSYSTEMS USA INC., Raleigh, NC. (919) 676-5292.