The RT8511A 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/1.2A power switch running at a fixed 1MHz 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 RT8511A is able to maintain steady control of the LED current. Therefore, no audible noises are generated on the output capacitor. The RT8511A also has programmable over voltage pin to prevent the output from exceeding absolute maximum ratings during open LED conditions. The RT8511A is available in WDFN-8L 2x2 and WDFN-8L 3x3 packages.


  • UMPC and Notebook Computer Backlight
  • GPS, Portable DVD Backlight
Key Spec.
Status Active
Vin (min) (V) 2.7
Vin (max) (V) 24
Vout (max) (V) 43
LED Channels 1
Topology Boost
SW Freq (typ) (kHz) 1000
Vcs (typ) (mV) 200
Dimming Control PWM-to-Analog
Features Backlight;Cycle-by-Cycle Current Limit;OCP;OVP;SCP
Package Type WDFN2x2-8;WDFN3x3-8
  • Wide Input Voltage Range : 2.7V to 24V
  • High Output Voltage : up to 43V
  • Direct PWM Dimming Control and Frequency from 100Hz to 1kHz
  • Internal Soft -Start and Compensation
  • 200mV Reference Voltage
  • PWM Dimming with Internal Filter
  • Programmable Over Voltage Protection
  • Over Temperature Protection
  • Current Limit Protection
  • Thin 8-Lead 2x2 and 8-Lead 3x3 WDFN Packages
  • RoHS Compliant and Halogen Free
TitleLast UpdateDownload
43V Asynchronous Boost WLED Driver2011/10/05