Led driver using LM3492 IC
Using the LM3492 integrates a boost converter and a two-channel current regulator integrated circuit you can design a very simple high efficient and cost effective LED driver for driving two individually dimmable LED strings with a maximum power of 15W and an output voltage of up to 65V.
The boost converter employs a proprietary Projected-On-Time control method to give a fast transient response with no compensation required, and a nearly constant switching frequency programmable from 200 kHz to 1 MHz.
The programmable peak current limit and soft-start features reduce current surges at startup, and an integrated 190 mΩ, 3.9A N-Channel MOSFET switch minimizes the solution size.
The LED current is programmable from 50 mA to 200 mA by a single resistor.
The LM3492 comes with a versatile COMM pin which serves as a bi-directional I/O pin interfacing with an external MCU for the following functions: power-good, over-temperature, IOUT over- and under-voltage indications, switching frequency tuning, and channel 1 disabling. Other supervisory functions of the LM3492 include precise enable, VCC under-voltage lockout, current regulator over-power protection, and thermal shutdown protection.
The following circuit LED driver based on the LM3492 require an input voltage ranged from 9V to 24V and it has two LED strings consists of 10 LEDs each with a forward voltage of 3.8V for each LED when running at 200 mA. The output power is 15.2W. The switching frequency fSW is designed to be 300 kHz .