DATASHEET
ISL97635 FN6434
Rev.3.00
Sep 26, 2017 SMBus 8-Channel LED Driver
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 В±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.
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 …