Converter Eases Implementation Of ISDN Power Supply Designs

Compared to typical solutions, the Si9121DY buck/boost converter IC is claimed to reduce component count by 20% in ISDN power-supply designs. The device operates across the entire input range of -10V to -60V and provides efficiencies of greater than 70% when converting a -48V input voltage to +3.3V at 400 mA. When converting a -60V input to +5V at 35 mA, under light-load conditions, the device can achieve efficiencies in excess of 60%. Other features include thermal shutdown, cycle-by-cycle current limiting, and a built-in hiccup mode timer that allows the device to handle a continuous output short-circuit and to automatically restart when the short circuit is removed. Lead times are 10 weeks for larger order, with pricing starting at $1.55 each/100,000.