SC441

SC441 High Efficiency Integrated Driver for 4-Strings of 150mA 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 150mA per string „ +/- 2% string-to-string current matching „ Up to 90% efficiency „ Wide 0.2% to 100% PWM dimming range www.DataSheet4U.com „ Possible analog dimming „ Integrated 2.5A power switch „ 800kHz 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 RoHS compliant „ 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 150mA 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 800kHz switching frequency enables the user to optimize the external component 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 ...