SC441 Datasheet | SEMTECH

High Efficiency Integrated Driver for 4-Strings of 150m A LEDs POWER MANAGEMENT Features Wide input voltage range from 4.5V to 21V - 36V maximum output voltage - Drives up to 40 WLEDs in 4 strings - Programmable LED current for up to 150m A per string - +/- 2% string-to-string current matching - Up to 90% efficiency - Wide 0.2% to 100% PWM dimming range .. - Possible analog dimming - Integrated 2.5A power switch - 800k Hz switching frequency for small size - Adjustable OVP for cost-effective output cap selection - Open/short LED protection - Thermal protection with auto-recovery - Thermally enhanced TSSOP-20 EDP package - Fully WEEE and Ro HS pliant - Description The SC441 is a high-efficiency multiple string WLED driver with an integrated boost converter. It operates over a wide input range from 4.5V to 21V with a maximum output voltage of 36V and a 2.5A internal power switch. It can drive up to forty WLEDs in 4 strings with current up to 150m A per string. The string-to-string current matching is 2% typical, 3% maximum. The overall efficiency is greater than 90% due to the low current sense voltage and a low-impedance internal power switch. The wide PWM dimming range boasts a ratio of 500: 1. The 800k Hz switching frequency enables the user to optimize the external ponent sizes for efficiency. When there are fewer than 10 LEDs in each string, users can adjust the output voltage protection yielding an allowable reduction in associated costs, size and voltage ratings of the output capacitor. The SC441 also Features prehensive open and shortcircuit LED protection functions. It disables the corresponding strings with LED open or LED short conditions while maintaining normal operation of other, unaffected LED strings. This feature allows LCD panels to remain viewable even under LED failure, wire disconnect, or short-circuit conditions. The internal thermal shutdown protects the IC from overheating at abnormal conditions. The SC441 is...