LM3643A

Product Folder Sample & Buy Technical Documents Tools & Software Support & Community LM3643, LM3643A SNVS967A – AUGUST 2014 – REVISED NOVEMBER 2014 LM3643 Synchronous Boost Dual LED Flash Driver with 1.5-A High-Side Current Sources 1 Features 1 1.5 A Total Allowed LED Current During Operation (ILED1 + ILED2 = 1.5 A) Dual Independent LED Current Source Programmability Accurate and Programmable LED Current Range from 1.4 mA to 1.5 A Optimized Flash LED Current During Low Battery Conditions (IVFM) > 85% Efficiency in Torch Mode (@ 100 mA) and Flash Mode (@1 A to 1.5 A) Grounded Cathode LED Operation for Improved Thermal Management Small Solution Size: < 16 mm2 Hardware Strobe Enable (STROBE) Synchronization Input for RF Power Amplifier Pulse Events (TX) Hardware Torch Enable (TORCH/TEMP) Remote NTC Monitoring (TORCH/TEMP) 400-kHz I2C-Compatible Interface – LM3643 (I2C Address = 0x63) – LM3643A (I2C Address = 0x67) 2 Applications Camera Phone White LED Flash 3 Description The LM3643 is a dual LED flash driver that provides a high level of adjustability within a small solution size. The LM3643 utilizes a 2-MHz or 4-MHz fixedfrequency synchronous boost converter to provide power to the dual 1.5-A constant current LED sources. The total LED current the LM3643 boost can deliver is 1.5 A (ILED1 + ILED2 ). The dual 128 level current sources provide the flexibility to adjust the current ratios between LED1 and LED2 with each driver capable of delivering a m...