The ISL97635A is a digitally controlled LED driver that controls 6 channels of LED current for LCD backlight applications. The ISL97635A can drive typically 54 (6x9) pieces of 3.5V/30mA or 60 (6x10) pieces of 3.2V/20mA LEDs. The ISL97635A contains 6 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 ISL97635A features a dynamic headroom control that monitors the highest LED forward voltage string and uses its feedback signal for output regulation. The LED dimming control can be achieved through a SMBus, an external PWM, or a variable DC (analog light sensor) input. SMBus controlled dimming allows 256 levels each of PWM and DC current adjustments. The SMBus PWM dimming frequency can be adjusted from 100Hz to 5kHz by an external capacitor. External PWM input allows up to 20kHz audio noise free PWM dimming. The SMBus PWM setting and an external PWMI signal can be synchronized for dimming.
The ISL97635A LED driver provides six independent current‑controlled channels, each capable of driving up to 30 mA LED strings. It features dynamic headroom control, 1 % channel‑to‑channel current matching, and protection functions such as open/short detection, OVP, OTP and thermal shutdown.
The device operates from a 6 V to 24 V supply, supports SMBus, external PWM and analog dimming, and is offered in a 24‑lead 4 mm × 4 mm QFN package suitable for notebook, monitor and automotive displays.
| Input voltage range | 6 V to 24 V |
|---|---|
| Output voltage (max) | 34.5 V |
| Number of LED channels | 6 |
| Package type | 24‑lead QFN (4 mm × 4 mm) |
The ISL97635A provides six independent LED channels.
Dimming can be performed via SMBus, an external PWM input, or a variable DC (analog light sensor) input.
The driver operates from 6 V up to 24 V.