DER-357: 170mA @ 75V Max, 90 ~ 132VAC in

This document is an engineering report describing a non-isolated buck-boost configured LED driver (power supply) utilizing a LYT4313E from the LYTSwitch family of devices. The DER-357 provides a single 12 W TRIAC dimmable constant current output.

The key design goals were high efficiency to maximize efficacy and small size. This allowed the driver to fit into BR40 sized lamps and be as close to a production design as possible.

The board was optimized to operate across a low-line AC input voltage range (90 VAC to 132 VAC, 47 Hz to 63 Hz). LYTSwitch IC based designs provide a high power factor (>0.95) meeting all current international requirements.

The form factor of the board was chosen to fit into a standard BR40 LED replacement lamp. The output is non-isolated and requires the mechanical design of the enclosure to isolate the output of the supply and the LED load from the user.

The document contains the power supply specification, schematic, bill of materials, transformer documentation, printed circuit layout, design spreadsheet and performance data.