AP3156 HIGH EFFICIENCY 1X/1.5X/2X CHARGE PUMP FOR WHITE LED APPLICATIONS Features General Description The AP3156 is a low noise, constant frequency charge pump V Range: 2.7V to 5.5V IN DC/DC converter that uses a tri-mode load switch (1X), fractional Fully Programmable Current with Single Wire (1.5X), and doubling (2X) conversion to maximize efficiency for 32-Step Logarithmic Scale white LED applications. The AP3156 is capable of driving the 20/25mA Max Current per Channel LED channels at 120mA maximum from a 2.7V to 5.5V input. The Four Low Current Settings Down to 50A current sinks may be operated individually or in parallel for driving Low I (50A) for Low Current Mode Q higher-current LEDs. A low external parts count (two 1F flying Tri-Mode 1X, 1.5X, and 2X Charge Pump for Maximum capacitors and two small 1F capacitors at V and V ) make IN OUT Efficiency and V Coverage this part ideally suited for small, battery-powered applications. F Drives up to Six Channels of LEDs AP3156 serial digital input is used to enable, disable and set Individual Main/Sub-Group Control current for each LED with a 32-level logarithmic scale plus four No Inductors, Low Noise Operation low-current settings down to 50A for optimized efficiency, with a 0.5/1/2MHz Constant Switching Frequency low quiescent current of only 50A. Small Application Circuit Built-In Thermal Protection Each output of the AP3156 is equipped with built-in protection for V short circuit and auto-disable for LED failure conditions. Built-In Auto-Disable For Open Circuit OUT Built-in soft-start circuitry prevents excessive inrush current Automatic Soft Start during start-up. A low-current shutdown feature disconnects the I <1A in Shutdown Q load from V and reduces quiescent current to less than 1A. IN Thermally-Enhanced QFN4040-16 Package: Available in Green Molding Compound (No Br, Sb) The AP3156 is available in a lead-free, space-saving, thermally Lead Free Finish / RoHS Compliant (Note 1) enhanced 16-pin 4x4mm QFN package. Applications Color (RGB) Lighting Programmable Current Sinks White LED Backlighting White Photo Flash for Digital Still Cameras Typical Application Circuit 10 5 V V IN IN C2 P 1uF 1uF C 8 2 C IN C2 N 6 C1 P 1uF C 7 1 C1 N AP3156 4 V OUT 1uF D6 D5 D4 D3 D2 D1 C OUT LED LED LED LED LED LED 2 1 SDI SDI D6 16 D5 15 D4 14 D3 13 D2 12 D1 GND 9,11 AP3156 Rev. 1 1 of 15 SEPTEMBER 2009 www.diodes.com Diodes Incorporated AP3156 HIGH EFFICIENCY 1X/1.5X/2X CHARGE PUMP FOR WHITE LED APPLICATIONS Ordering Information AP 3156 FV G - 7 Package Lead Free Packing FV : QFN4040-16 7 : Tape & Reel G : Green Package Packaging 7 Tape and Reel Device Code (Note 2) Quantity Part Number Suffix AP3156FVG-7 FV QFN4040-16 1500/Tape & Reel -7 Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at