Abstract
In recent years, high-power white LED (Light Emitting Diode) technology has been greatly developed. LED is a kind of solid light source. It has an enormous application prospect because of its advantages , such as energy conservation, environmental protection, firm structure, long life, short start-up time, small volume, low operating voltage.
The LED lighting system needs an AC/DC converter. In the past, the general use of AC / DC converter was made by separate devices as a power source, and using mains alternating current to power supply. As the loss of AC / DC circuit and current control circuit, resulting that it has no advantage of LED lighting compared to traditional incandescents and fluorescent lamps.
As semiconductor manufacturing technology development and high-voltage BCD process maturity, there 500V high-voltage capability of metal oxide semiconductor field effect transistor(MOSFET), making design and manufacture of high-voltage integrated circuits as possible.
In this paper, we adopt a 85V-265V AC input to support the constant current control chip, and design a small size, high efficiency, stable, inexpensive PWM (Pulse Width Modulation) switching power supply for high-power white LED constant current driver .The measured power efficiency up to 90%. As the chip has been over-temperature protection, output short circuit protection and output open-circuit protection design, so this design of the circuit is very safe and suitable for systems that require high efficiency, high safety requirements in the actual lighting.
Keywords: White LED , switching power supply , constant current drive
