Dual LED Flash Driver Capable of up to 1.5A - LM3643

LM3643 (ACTIVE)

Dual LED Flash Driver Capable of up to 1.5A

 

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 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.

Features

  • 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)

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Parametrics Compare all products in Strobe & Flash LED Driver

 
Vin (Min) (V)
Vin (Max) (V)
LED (#)
Iout (Max) (A)
Iq (Typ) (mA)
Features
Operating Temperature Range (C)
Pin/Package
Rating
LM3643 LM3559 LM36010 LM36011 LM3642 LM3644 LM3648
2.5    2.5    2.5    2.5    2.5    2.5    2.5   
5.5    5.5    5.5    5.5    5.5    5.5    5.5   
2    2    1    1    1    2    1   
1.5    1.8    1.5    1.5    1.5    2.5    1.5   
0.3    0.65    0.3    0.3    0.75    0.3    0.3   
I2C Control
LED Thermal Monitor
OVP
Over Current Protection
Synchronous Rectification   
I2C Control
Input/Output Isolation
LED Thermal Monitor
Load Disconnect During Shutdown
OVP
Over Current Protection
Synchronous Rectification   
I2C Control
IR Mode
OVP
Synchronous Rectification   
I2C Control    Input/Output Isolation
Over Current Protection
OVP
Synchronous Rectification   
I2C Control
IR Mode
LED Thermal Monitor
OVP
Over Current Protection
Synchronous Rectification   
I2C Control
IR Mode
LED Thermal Monitor
OVP
Over Current Protection
Synchronous Rectification   
-40 to 85    -40 to 85    -40 to 85    -40 to 85    -40 to 85    -40 to 85    -40 to 85   
12DSBGA    16DSBGA    8DSBGA    8DSBGA    9DSBGA    12DSBGA    12DSBGA   
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