A PWM Mini-LED Pixel Circuit with Source-Follower Compensation Structure

This paper proposes a novel mini-light-emitting diode (mini-LED) pixel circuit using the pulse width modulation (PWM) driving method. The circuit compensates for the variations in threshold voltage (V
TH
) of driving thin-film transistor (TFT) through a source-follower structure and current-resistance (I-R) drops in power lines to generate a stable driving current for mini-LED. The PWM driving method enables the operation of mini-LED at peak luminous efficacy, and the number of TFTs along the driving current path is reduced, effectively lowering power consumption. Furthermore, to precisely modulate the emission duration, V
TH
variations of the switching TFT are also compensated using source follower. Simulation results show current error rates below 5.48% and emission time shifts less than 3
$\mu \mathrm{s}$
.