ISL97678 8 channel LED driver circuit

Intersil Technology has introduced the ISL97678 8-channel PWM dimming LED driver useful in LCD backlight applications. The ISL97678 LED Driver is capable of driving up to 96 pieces of 3.4V/50mA LEDs but is possible to drive larger numbers of LEDs if the LED forward voltage combined is less than 45V.

The ISL97678 contains 8 channels of voltage controlled current sources with typical currents matching to ±1%  .

The ISL97678 LED driver has many other features like : Drive Typically 96 LEDs (3.4V/50mA each) ,  External PWM Input up to 25kHz Dimming , Dimming range 0.8%~100% up to 30kHz , Current Matching ±0.7% , short circuit and open circuit detections, adjustable dimming frequency , adjustable switching frequency.

The Intersil ISL97678 allows two ways of controlling the LED current, and therefore, the brightness :

- DC current adjustment

- PWM chopping of the LED current

In both dimming controls the EN pin (high voltage pin ) must be high.