LM3644

Product Folder Sample & Buy Technical Documents Tools & Software Support & Community LM3644, LM3644TT SNVSA52E – AUGUST 2014 – REVISED SEPTEMBER 2016 LM3644 Dual 1.5-A Current Source Camera Flash LED Driver 1 Features 1 Dual Independent 1.5-A LED Current Source Programmability Accurate and Programmable LED Current Range from 1.4 mA to 1.5 A Torch Currents up to 360 mA (LM3644TT) Flash Timeout Values up to 1.6 seconds (LM3644TT) Optimized Flash LED Current During Low Battery Conditions (IVFM) > 85% Efficiency in Torch Mode (at 100 mA) and Flash Mode (at 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 – LM3644 (I2C Address = 0x63) 2 Applications Camera Phone White LED Flash Digital Still Cameras Fire-Alarm Notification Emergency Strobe Lighting Intruder Alert Notification Barcode Scanners Handheld Data Terminals 3 Description The LM3644 is a dual LED flash driver that provides a high level of adjustability within a small solution size. The LM3644 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 dual 128 level current sources provide the flexibility to adjust the current ratios between LED1 and...