The RT8511B is an LED driver IC that can support up to 10 WLED in series. It is composed of a current mode boost converter integrated with a 43V/2.2A power switch running at a fixed 500kHz frequency and covering a wide VIN range from 2.7V to 24V.
The white LED current is set with an external resistor, and the feedback voltage is regulated to 200mV (typ.). During operation, the LED current can be controlled by the PWM input signal in which the duty cycle determines the feedback reference voltage.
For brightness dimming, the RT8511B is able to maintain steady control of the LED current. Therefore, no audible noises are generated on the output capacitor. The RT8511B also has programmable over voltage pin to prevent the output from exceeding absolute maximum ratings during open LED conditions. The RT8511B is available in WDFN-8L 2x2 package.