LED Backlight Driving Boost Switch

The FAN73402 is a single-channel boost controller that integrates an N-channel power MOSFET for PWM dimming using onsemi’s proprietary planar Double-diffused MOSFET (DMOS) technology. The IC operates as a constant-current source for driving high-current LEDs. It uses Current Mode control with programmable slope compensation to prevent subharmonic oscillation. The IC provides protections including: open-LED protection, over-voltage protection, and direct-short protection for high system reliability. The IC internally generates a FAULT signal with delay if an abnormal LED string condition occurs. PWM dimming and analog dimming functions can be implemented independently. Internal soft-start prevents inrush current flowing into output capacitor at startup.