The LM3645 is a quad LED flash driver that provides a high level of adjustability within a small solution size. The LM3645 utilizes a synchronous boost converter to provide power to the quad 2A constant current LED sources. The quad 256 level current sources provide the flexibility to adjust the current ratios between LED1, LED2, LED3 and LED4 with each driver capable of delivering a maximum of 2A. An adaptive regulation method ensures the current sources remain in regulation and maximizes efficiency.

Features of the LM3645 are controlled via an I2C-compatible interface. These features include: dual hardware flash pins and a hardware torch or Tx interrupt pin (STR1, STR2 and TORCH/TX), and dual NTC thermistor monitors. The device offers independently programmable currents in each output leg to drive the LEDs in a flash or movie mode (Torch) condition as well as a fast turn-on and turn-off IR Mode.

Two switching frequency options, overvoltage protection (OVP), and adjustable current limit allow for the use of tiny, low-profile inductors and 10µF ceramic capacitors. The device operates over a –40°C to +85°C ambient temperature range.Read more