LM3509

LM3509 www.ti.com SNVS495D – FEBRUARY 2007 – REVISED MAY 2013 LM3509 High Efficiency Boost for White LED's and/or OLED Displays with Dual Current Sinks and I2C Compatible Brightness Control Check for Samples: LM3509 FEATURES 1 2 Integrated OLED Display Power Supply and LED Driver Drives up to 10 LED’s at 30mA Drives up to 5 LED’s at 20mA and Delivers up to 21V at 40mA Over 90% Efficient 32 Exponential Dimming Steps 0.15% Accurate Current Matching Between Strings Internal Soft-Start Limits Inrush Current True Shutdown Isolation for LED’s Wide 2.7V to 5.5V Input Voltage Range 21V Over-Voltage Protection 1.27MHz Fixed Frequency Operation Low Profile 10-Pin WSON Package (3mm x 3mm x 0.8mm) General Purpose I/O Active Low Hardware Reset APPLICATIONS Dual Display LCD Backlighting for Portable Applications Large Format LCD Backlighting OLED Panel Power Supply DESCRIPTION The LM3509 current mode boost converter offers two separate outputs. The first output (MAIN) is a constant current sink for driving series white LED’s. The second output (SUB/FB) is configurable as a constant current sink for series white LED bias, or as a feedback pin to set a constant output voltage for powering OLED panels. Typical Application Circuits 10 PH 2.7V to 5.5V CIN 1 PF 10 k: 10 k: SW IN OVP LM3509 VIO SCL SDA MAIN SUB/FB RESET/GPIO SET GND 30 mA per string COUT 1 PF RSET 8 k: Dual White LED Bias Supply 1 Please be aware that an important notice conc...