LED lighting power supplies come in many varieties. They can be as simple as a series resistor or as complicated as a switching power supply with 5000:1 dimming. Probably the most popular way to drive an LED is a constant current source, implemented by using a transistor as a linear element or a switching power supply, but there are many approaches using both voltage and current control. Linear supplies are often limited by the power dissipation but switching power supplies have excellent efficiency and can drive LEDs from a few hundred mW to a few hundred Watt.

Dimming plays a very important part in LED driving and may be implemented either by modulating the LED current or by PWM. Current dimming is simple but low driving currents may cause a color shift for the LED. PWM allows dimming down to a very low value with no color shifting but adds to complexity and difficulty. Low duty cycles and/or high PWM frequencies require precise tuning of the switching power supply.

Our team has a vast experience in LED lighting, having designed various power LED and RGB LED control boards.