The LM3492 integrates a boost converter and a two-channel
current regulator to implement a 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 application circuit is stable with ceramic capacitors and
produces no audible noise on dimming. 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 fast slew
rate current regulator allows high frequency and narrow pulse
width dimming signals to achieve a very high contrast ratio of
1000:1 at a dimming frequency of more than 3 kHz. The LED
current is programmable from 50 mA to 200 mA by a single resistor.