Boost LED driver for LED backlight system

Introduction: in the surrounding environment can be higher brightness brightness, and in the surrounding environment is dark, you can reduce the brightness, in order to prevent the driver's eyes can not adapt to the sharp changes in brightness, driving safety.

In general application situation, we will use the boost constant current LED drive on a large number of more than LED, the LED backlight system this configuration can provide backlight for dashboard and display vehicle navigation system.

In addition, the automotive dashboard display must be equipped with dimming control function to control the brightness of the LED backlight. Such as in the surrounding environment can be higher brightness brightness, and in the surrounding environment is dark, you can reduce the brightness, in order to prevent the driver's eyes can not adapt to the sharp changes in brightness, driving safety.

Boost LED driver for LED backlight system

In addition, the controller with PWM dimming function must have a good contrast, which has a good linear adjustment. The PWM signal is on the pulse signal, we can switch to control the current through the switch pulse emission, LED issued more than 100Hz in the visual flash, so we feel the brightness has been reduced, because the human eye will filter / average brightness.

Dimming function is good or bad by dimming the duty cycle to achieve, if the duty cycle of the device is very small, then the scope of dimming will be larger, with better linearity. There are usually two ways: one is to simulate the signal dimming, and the other is the dimming of the PWM signal.

Because the analog dimming is achieved by changing the current of the LED, when the current of the LED changes, the color of the LED will also change, so we usually choose PWM dimming as the brightness control method. When this method is used, the LED can either be turned on or off, and will not change the color of the LED.