The Limitation of Threshold-Voltage Compensation Range for Internal Compensation Circuit in the AM-MiniLED Pixel Structure

Internal compensation circuit cannot effectively compensate for the threshold-voltage shift of the driving thin-film transistor especially in the field of small pitch and low gray scale in Active Matrix Mini& Micro-LED display. Through the simulation of a mature internal circuit with source follow structure, we simulate and calculate the compensation range, threshold-voltage shift value and the current of LED. According to the result, the root cause for threshold-voltage shift compensation limitation lies in the inaccuracy of threshold-voltage detection in the period of detecting period, which is owing to the different status among driving TFT under different threshold-voltage shift conditions. To some extent, increasing the detecting time can decrease the loss value of detecting threshold-voltage and improve the compensation range of the threshold-voltage.