Press Release Summary:
Capable of driving 96 pieces of 3.4 V/50 mA LEDs, 8-channel Model ISL97677 is suited for notebook and monitor LCD backlight applications with PWM dimming and fault reporting functions. Unit has multiple channels of voltage controlled current sources with typical currents matching Â±0.7%, which compensate for non-uniformity effect of forward voltage variance in LED strings. Housed in 5 x 5 mm QFN package, Model ISL97677 operates from -40 to +85Â°C with input voltages from 4.75-26 V.
Original Press Release:
ISL97677 SMBus/I2C 8-Channel LED Driver
The ISL97677 is an SMBus/I2C controlled multi-channel LED driver for notebook and monitor LCD backlight applications with PWM dimming and fault reporting functions. The ISL97677 is capable of driving typically 96 pieces of 3.4V/50mA LEDs. The ISL97677 has multiple channels of voltage controlled current sources with typical currents matching to ±0.7%, 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 ISL97677 features dynamic headroom control that monitors the highest LED forward voltage string and uses its feedback signal for output regulation.
The ISL97677 can operate in multiple modes of operations. It can be controlled by SMBus/I2C communications and an external PWM dimming signal with currents matching of ±1% across all ranges.
The ISL97677 features extensive protection functions that include string open and short circuit detections, OVP, and OTP. The fault conditions will be recorded in the Fault/Status register. There are selectable short-circuit thresholds and the switching frequency can be programmed between 500kHz and 1.5MHz.
ISL97677 is available in the 32 Leads QFN 5mmx5mm and operate from -40°C to +85°C with input voltage ranges from 4.75V to 26V.