Catalog
Dual LED flash driver Capable of up to 1.5A
Key Features
• 1.5 A Total Allowed LED Current During Operation(ILED1+ ILED2= 1.5 A)Dual Independent LED Current Source ProgrammabilityAccurate and Programmable LED Current Range from1.4 mA to 1.5 AOptimized Flash LED Current During Low BatteryConditions (IVFM)> 85% Efficiency in Torch Mode (@ 100 mA) andFlash Mode (@1 A to 1.5 A)Grounded Cathode LED Operation for Improved ThermalManagementSmall Solution Size: < 16 mm2Hardware Strobe Enable (STROBE)Synchronization Input for RF Power Amplifier PulseEvents (TX)Hardware Torch Enable (TORCH/TEMP)Remote NTC Monitoring (TORCH/TEMP)400-kHz I2C-Compatible InterfaceLM3643 (I2C Address = 0x63)LM3643A (I2C Address = 0x67)1.5 A Total Allowed LED Current During Operation(ILED1+ ILED2= 1.5 A)Dual Independent LED Current Source ProgrammabilityAccurate and Programmable LED Current Range from1.4 mA to 1.5 AOptimized Flash LED Current During Low BatteryConditions (IVFM)> 85% Efficiency in Torch Mode (@ 100 mA) andFlash Mode (@1 A to 1.5 A)Grounded Cathode LED Operation for Improved ThermalManagementSmall Solution Size: < 16 mm2Hardware Strobe Enable (STROBE)Synchronization Input for RF Power Amplifier PulseEvents (TX)Hardware Torch Enable (TORCH/TEMP)Remote NTC Monitoring (TORCH/TEMP)400-kHz I2C-Compatible InterfaceLM3643 (I2C Address = 0x63)LM3643A (I2C Address = 0x67)
Description
AI
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 fixed-frequency 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 maximum of 1.5 A (ex: ILED1= 1.5 A and ILED2= 0FF, ILED1= 0FF and ILED2= 1.5 A, or a current configuration with a current less than 1.5 A , ILED1= 950 mA and ILED2= 250 mA). An adaptive regulation method ensures the current sources remain in regulation and maximizes efficiency.
Features of the LM3643 are controlled via an I2C-compatible interface. These features include: hardware flash and hardware torch pins (STROBE and TORCH/TEMP), a TX interrupt, and an NTC thermistor monitor. The device offers independently programmable currents in each output leg to drive the LEDs in a Flash or Movie Mode (Torch) condition.
The 2-MHz or 4-MHz switching frequency options, overvoltage protection (OVP), and adjustable current limit allow for the use of tiny, low-profile inductors and (10-µF) ceramic capacitors. The device operates over a –40°C to 85°C ambient temperature range.
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 fixed-frequency 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 maximum of 1.5 A (ex: ILED1= 1.5 A and ILED2= 0FF, ILED1= 0FF and ILED2= 1.5 A, or a current configuration with a current less than 1.5 A , ILED1= 950 mA and ILED2= 250 mA). An adaptive regulation method ensures the current sources remain in regulation and maximizes efficiency.
Features of the LM3643 are controlled via an I2C-compatible interface. These features include: hardware flash and hardware torch pins (STROBE and TORCH/TEMP), a TX interrupt, and an NTC thermistor monitor. The device offers independently programmable currents in each output leg to drive the LEDs in a Flash or Movie Mode (Torch) condition.
The 2-MHz or 4-MHz switching frequency options, overvoltage protection (OVP), and adjustable current limit allow for the use of tiny, low-profile inductors and (10-µF) ceramic capacitors. The device operates over a –40°C to 85°C ambient temperature range.
