Buck Controllers Power LEDs Offline

From International Rectifier (www.irf.com), the IRS254x is a series of high-voltage, high-frequency buck regulator controllers for ac-dc offline, nonisolated applications requiring multiple LED circuits or requiring dc-dc color-mixing capabilities. Applications include indoor and outdoor signage as well as architectural, entertainment, design and decorative lighting.

Rated at 200 V or 600 V, the IRS254x series incorporates a continuous-mode, time-delayed hysteretic buck regulator to control the average load current within a tolerance of 5% . An external high-side bootstrap circuit drives the buck switching element at high frequencies up to 500 kHz. A low-side driver is also provided for synchronous rectifier designs. Offered in 8-pin DIP or SOICs, the controllers startup using less than 500 µA and feature a deadtime of 140 ns for continuous current regulation. In 10,000 unit quantities, unit pricing begins at $0.81.