The ISL97635 is a digitally controlled LED driver that controls 8 channels of LED current for LCD backlight applications. The ISL97635 is capable of driving typically 72 (8x9) pieces of 3.5V/30mA or 80 (8x10) pieces of

3.2V/20mA LEDs. The ISL97635’s 8 channels of voltage controlled current sources with typical currents matching of ±1, which compensate for the non-uniformity effect of forward voltages variance in the LED stacks. To minimize the voltage headroom and power loss in the typical multi-strings operation, the ISL97635 features a dynamic headroom control that monitors the highest LED forward voltage string and uses its feedback signal for output regulation.

Features

• 8 Channels

• 6V to 24V Input

• 34.5V Output Max

• Drive Maximally 72 (3.5V/30mA each) or 80 (3.2V/20mA each) LEDs

• Current Matching ±1 Typ

• Dynamic Headroom Control

• Dimming Controls

- SMBus 8-Bit PWM Current Control

- SMBus 8-Bit DC Current Control

- External PWM Input up to 20kHz Dimming

- SMBus and External PWM DPST Dimming Control

- DC-to-PWM Dimming Control

• Protections

- String Open Circuit Detection

- String Short Circuit Detection with Selectable Thresholds

- Over-Temperature Protection

- Overvoltage Protection

- Input Overcurrent Protection with Disconnect Switch

• 600kHz/1.2MHz Selectable fSW

• Selectable Channels Allows Scrolling Backlight

• 24 Ld (4mmx4mm) QFN Package

• Pb-Free (RoHS compliant)

Applications

• Notebook Displays WLED or RGB LED Backlighting

• LCD Monitor LED Backlighting

• Automotive Displays LED Backlighting

• Automotive or Traffic Lighting