10W non-isolated mains-to-dc converter

It has an internal 700V mosfet and works with mains from 85Vac to 300Vac, and typically with peak current up to 1.1A.

“A key differentiator of this switcher IC is that it supports conventional off-line non-isolated fly-back configurations, as well as more streamlined non-isolated buck configurations,” according to the company. “Peak current and switching frequency will continuously reduce as the load decreases, meaning that this device can achieve heightened degrees of efficiency in light load conditions. It is thereby suited for any form of equipment that spends prolonged time in sleep mode.”

Called AP3928, it comes in an SO-8 package and manages its own Vcc by turning on and off an internal regulator. A modified arrangement, where an auxiliary Vcc supply is implemented (right), can cut no-load power to 30mW.

Over-temperature, output short, over-load and open-loop protection is included, as well as under-voltage lock-out. It can operate at junction temperatures up to +150°C.