The ISL97678IRZ-TK is an 8-channel PWM dimming LED driver for LCD backlight applications. The ISL97678IRZ-TK is capable of driving up to 96 pieces of 3.4V/50mA LEDs but larger numbers of LEDs are possible if the LED forward voltage combined is less than 45V. The ISL97678IRZ-TK has 8 channels of voltage controlled current sources with typical currents matching to ±1%, which compensate for the non-uniformity effect of forward voltages variance in the LED strings. To minimize the voltage headroom and power loss in the typical multi-string operation, the ISL97678IRZ-TK features dynamic headroom control that monitors the highest LED forward voltage string and uses its feedback signal for output regulation.The ISL97678IRZ-TK features PWM dimming up to 30kHz with 0.4%~100% duty cycle and maintains ±1% current matching across all ranges. The PWM dimming frequency can be adjusted between 100Hz and 30kHz. The boost switching frequency can also be adjusted between 600kHz and 1.5MHz.The ISL97678IRZ-TK features extensive protection functions that include string open and short circuit detections, OVP, and OTP.The ISL97678IRZ-TK is available in the 32 Ld QFN 5mmx5mm and operates from -40°C to +85°C with input voltage ranges from 4.75V to 26V.

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