Description

This design idea provides a simple non-isolated AC/DC power supply for low power applications such assmart grid E-meter applications. The design uses a capacitive-dropper front-end combined with aLM46000 SIMPLE SWITCHER® buck regulator from Texas Instruments. The circuit provides 3.3 V at aminimum of 50 mA from a line supply of 90 VAC to 265 VAC. Theory of operation as well as designequa