The RT4533/A is a highly integrated LED driver IC capable of driving 10 WLEDs in series. It is composed of a current mode Boost converter integrated with a 36.5V/1.2A power switch.
The RT4533/A supports a wide input voltage range from 2.5V to 5.5V and runs at a fixed frequency of 1.1MHz. The LED current is set via an external resistor and the feedback voltage is regulated to 200mV / 300mV.
For brightness dimming, the RT4533/A supports PWM dimming which determines the feedback reference voltage.