High-power fault-tolerant and multiple independent loads LED driver

Abstract

Fault-tolerant LED drivers offer advantages of uninterrupted operation under fault conditions, lower repair cost and downtime. Low-loss hall-effect current sensors were used to detect current flow in each string, and are seamlessly integrated with the digital control system to achieve a high-efficiency fault-tolerant driver. Existing LED lighting systems require a driver for each LED load. For applications where numerous LED loads are needed, the complexity and cost of the lighting system are likely to increase. In this paper, a simple novel LED driver for multiple independent LED loads is proposed. A digitally controlled coupled inductor cuk converter is employed. The coupled inductors lower output current ripple ensuring >99% LED load efficacy, and helps eliminate the output filter capacitor. This results in a highly efficient and compact LED driver.