A RGB-driver for LED display panels

Red-Green-Blue (RGB) light-emitting diodes display panels are finding widespread use due to recent advances in the light-emitting diodes (LEDs) and their driver technology. This paper investigates a digital microcontroller based RGB-driver for application in display panels. The RGB-driver uses three different voltage sources from switch-mode power converters (SMPCs) as each RGB color requires different drive voltages. The proposed driver selects the minimum drain voltage of the MOSFETs of the current controllers for each color and uses this voltage to control the duty cycle of the SMPCs, and thus, maintains the minimum output voltages required to keep the MOSFETs in the current controllers in regulation. With a 5-V supply voltage, the efficiencies of the RGB LEDs are 91.5%, 95.7%, and 95.7%, respectively. Even though the driver was experimentally verified in a 3 × 3 RGB pixels, the concept can be extended to a larger display matrix.