There are actually many LED dimming driver methods, which can be simply divided into digital dimming and analog dimming. PWM dimming belongs to digital dimming, which controls the brightness of the lamp by turning on and off the square wave to change the conduction time of the forward current.

It can be seen that the dimming principle of analog dimming and pwm dimming power supply is completely different. To sum up briefly, the former is the size of the current, and the latter is the duty cycle of the current to change the brightness of the light. I believe it will be easier for everyone to understand.

Let us first look at the problems of analog dimming. Analog dimming uses the magnitude of the adjustment current to change the brightness. When the current is reduced to a certain value, it is easy to produce color shift, that is, the color of the light drifts, and the pwm adjustment is used. When the light is on, the current is constant, so this problem will not occur.

Secondly, the analog dimming is within the adjustable current range, and the adjustable gear is limited; PWM wave dimming can arbitrarily change the turn-on time of the LED by changing the high and low duty cycle, thereby increasing the brightness adjustment gear.