Non-isolated buck switchers provide high voltage AC/DC conversion with low standby current

Diodes Incorporated has launched the AP3917 family of universal AC/DC, non-isolated buck (step-down) power switchers for low-power applications, including small appliances and IoT endpoints powered by an offline supply. Family members comprise the AP3917B (170mA nominal load), AP3917C (270mA), and AP3917D (370mA).

This family of buck switchers is intended to offer highly efficient, offline power conversion for light-load applications. Discontinuous and continuous conduction modes are also supported.

The buck switcher can convert a full-wave rectified, AC input voltage between 85VAC and 265VAC to a nominal 8VDC output. Its non-isolated design needs no external transformer and few external components, saving space and BOM cost.

With a no-load power consumption of lower than 30mW, these buck switchers are suitable for small appliances that work in standby mode for prolonged periods when connected to an AC outlet. Its low-power credentials and small solution size also make the devices ideal for IoT devices that are always connected but not constantly active.