Inverter-Based MicroLED Pixel Circuit Using LTPO TFTs Achieving Submicrosecond Pulse-Width Modulation With Low Power Consumption Through Dynamic SWEEP Generation

In this paper, we propose a pixel circuit for micro light-emitting diode displays based on low-temperature poly-Si oxide thin-film transistors. The proposed pixel circuit employs a dynamic SWEEP generation (DSG) scheme with an inverter, which steepens the slope of the internally generated SWEEP signal as the gray level decreases. Simulation results demonstrate that the proposed circuit achieves pulse-width modulation (PWM) down to a submicrosecond level, approximately $0.6~\mu $ s, with a falling time of $0.05~\mu $ s. This nearly ideal PWM operation enables the accurate expression of the lowest gray level down to 3 G. The proposed circuit also exhibited enhanced current uniformity and reduced inverter power consumption in low-gray levels. The average current error rate was less than 0.5% at 3 G, and the average inverter power in the mid- to low-gray levels was significantly reduced. This operational advancement was attributed to the adoption of a DSG scheme in the pixel circuit.