Offline Triac Dimmable Isolated LED Driver Demonstration Board

The ISL1904DEMO1Z demo board converts a high line AC input voltage to an 18V, 700mA DC output. It is implemented with Renesas' critical conduction mode (CrCM) LED driver controller, the ISL1904. It demonstrates the fundamental functions of ISL1904, including soft-start, dimming, over-voltage protection, short circuit protection, etc.

The circuit operates in CrCM with variable frequency and allows near zero-voltage switching (ZVS). Typical efficiency is about 81% at full load. The ISL1904DEMO1Z demo board supports phase dimming and is compatible with a wide variety of leading and trailing edge dimmers available in the market. This application note covers the performance data, critical waveforms, extensive dimming data, schematics, layout, and bill of materials.