AL3644CH12-7 Diodes Incorporated

AL3644 DUAL 1.5A CURRENT SOURCE CAMERA FLASH LED DRIVER Description Features The AL3644 is a dual LED flash driver that provides a high level of Dual Independent 1.5A LED Current Source Programmability adjustability within a small solution size. The AL3644 utilizes a 2MHz Accurate and Programmable LED Current Range from 1.4mA to or 4MHz fixed frequency synchronous boost converter to provide 1.5A power to the dual 1.5A constant current LED sources. The dual 128 Torch Currents up to 360mA (AL3644TT) level current sources provide the flexibility to adjust the current ratios Flash Timeout Values up to 1.6 seconds (AL3644TT) between LED1 and LED2. An adaptive regulation method ensures the Optimized Flash LED Current During Low Battery Conditions current sources remain in regulation and maximizes efficiency. (Input Voltage Flash Monitor) > 85% Efficiency in Torch Mode (at 100mA) and Flash Mode (at 2 Features of the AL3644 are controlled via an I C-compatible 1A to 1.5A) interface. These features include: hardware flash and hardware torch Grounded Cathode LED Operation for Improved Thermal pins (STROBE and TORCH/TEMP), a TX interrupt, and an NTC Management 2 thermistor monitor. The device offers independently programmable Small Solution Size: < 16mm currents in each output leg to drive the LEDs in a Flash or Movie Hardware Strobe Enable (STROBE) Mode (Torch) condition. Synchronization Input for RF Power Amplifier Pulse Events (TX) Hardware Torch Enable (TORCH/TEMP) The 2MHz or 4MHz switching frequency options, overvoltage Remote NTC Monitoring (TORCH/TEMP) 2 protection (OVP), and adjustable current limit allow for the use of tiny, 400kHz I C-Compatible Interface 2 AL3644 (I C Address = 0x63) low-profile inductors and (10F) ceramic capacitors. The device Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) operates over a 40C to +85C ambient temperature range. Halogen and Antimony Free. Green Device (Note 3) Applications Camera Phone White LED Flash Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant. 2. See AL3644 Typical Applications Circuit 1mH 2.5V to 5V SW IN OUT 10mF 10 mF AL3644 LED1 TORCH/ TEMP Flash STROBE LED HWEN LED2 TX SDA Flash SCL LED GND Pin Descriptions Pin Number Pin Name Type Function A1 GND Ground Ground. Input voltage connection. Connect IN to the input supply and bypass to GND with a 10F or A2 IN Power larger ceramic capacitor. 2 A3 SDA I/O Serial data input/output in the I C Mode on AL3644. B1 SW Power Drain Connection for Internal NMOS and Synchronous PMOS Switches. Active high hardware flash to enable. Drive STROBE high to turn on Flash pulse. Internal B2 STROBE I/O pulldown resistor of 300k between STROBE and GND. B3 SCL I/O Serial clock input for AL3644. Step-up DC-DC converter output. Connect a 10F ceramic capacitor between this pin and C1 OUT Power GND. Active high enable pin. High = Standby, Low = Shutdown/Reset. Internal pulldown resistor of C2 HWEN I/O 300k between HWEN and GND. C3 TORCH/TEMP I/O Torch terminal input or threshold detector for NTC temperature sensing and current scale back. D1 LED2 Power High-side current source output for flash LED. Configurable dual polarity power amplifier synchronization input. Internal pulldown resistor of D2 TX I/O 300k between TX and GND. D3 LED1 Power High-side current source output for flash LED. 2 of 23 AL3644 July 2019 Diodes Incorporated www.diodes.com Document number: DS41558 Rev. 1 - 2 NEW PRODUCT