Description

This 110-VAC to 5-VDC at 30-mA non-isolated power supply reference design uses a low-power: low-cost: off-line buck converter and a low-noise: low-dropout voltage regulator to generate a non-isolated 5-V/30-mA output directly from a 110-VAC line input with under 10-mV output ripple across no-load and full-load conditions. Off-line converters are powered directly from the AC line by using a rectifier and capacitive filter and do not require a large 60-Hz transformer: thereby eliminating the heaviest and costliest component of a typical transformer-based power supply. The entire reference design is implemented on a single-sided: double-layer board size of just 63.2 mm x 38.1 mm with a bill-of-material (BOM) count of 20 devices.