SC443 High Efficiency Integrated Boost Driver for 3-Strings of 30mA LEDs POWER MANAGEMENT Features Description Wide input voltage range from 4.5V to 27V The SC443 is a high-efficiency multiple string WLED driver 42V maximum operating output voltage with an integrated boost converter. It operates over a wide Programmable LED current for up to 30mA per input range from 4.5V to 27V with a maximum output string voltage of 42V and a 1A internal power switch. +/- 1% typical string-to-string current matching Greater than 90% efficiency It can drive 3 strings with current up to 30mA per string. Wide 0.4% to 100% PWM dimming range The string-to-string current matching is within, typically, Integrated 1A power switch 1% and the overall efficiency is greater than 90% due Programmable switching frequency for small size to the low current sense voltage and a low-impedance Low current sense voltage for high efficiency internal power switch. The wide PWM dimming range Adjustable OVP for cost- ef fective output cap boasts a ratio of 250: 1. selection LED open circuit protection The programmable switching frequency enables the Thermal protection with auto-recovery user to optimize the external component sizes for high 3mm 3mm 0.6mm MLP-UT-16 lead-free package efficiency. When there are fewer LEDs in each string, users (WEEE and RoHS compliant) can use a lower output voltage protection level which yields an allowable reduction in associated costs, size and voltage ratings of the output capacitor. Applications The SC443 also features an open circuit LED protection Small to Medium Size LCD Panel function. It disables the corresponding strings with LED Notebook Display open while keeping other strings under normal operation. White LED Power Supplies This feature allows LCD panels to remain viewable even Sub-Notebook and Tablet Computer Displays under LED failure and wire disconnectons. The internal Portable Media Players thermal shutdown protects the IC from overheating at LCD Monitors abnormal conditions. The SC443 is available in a 3mm Digital Video Cameras 3mm 0.6mm MLP-UT 16 Lead-free package. Typical Application Circuit V IN SW VIN VOUT OOVVPPIINN COMP AAGGNNDD SS SC443 3 IO1-3 FSET IOSET Enable EN IOGND Dimming PWM PGND January 21, 2009 www.semtech.com 1SC443 Pin Configuration Ordering Information Device Package (1)(2) SC443ULTRT 3 x 3 x 0.6mm MLP-UT 16 SC443EVB Evaluation Board 16 15 14 13 Notes: (1) Available in tape and reel only. A reel contains 3,000 devices. TOP VIEW 12 IOGND VOUT 1 (2) Available in lead-free package only. Device is WEEE and RoHS compliant. IO2 PGND 2 11 SW 3 10 IO3 9 COMP 4 VIN T 5 6 7 8 = 38C JA MLP-UT-16 5 4 3 2 1 Marking Information D D C C B B 2009 Semtech Corp. www.semtech.com 2 A A TTTiiitltltleee <<<TTTiiitltltle>e>e> SSSiiizzzeee DDDocococumumument Nent Nent Numumumberberber RRRevevev AAA <<<DDDocococ>>> <<<RRRevevevCCCode>ode>ode> DDDate:ate:ate: MMMondayondayonday, F, F, Febrebrebruaruaruaryyy 25, 2008 25, 2008 25, 2008 SSSheetheetheet 111 ofofof 111 5 4 3 2 1 EN FSET AGND IO1 PWM OVPIN SS IOSET