A new pre-bootstrapping method (PBM) using hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) for a gate driver that is used in high-frame-rate or high-resolution displays is presented in this article. The PBM utilizes the capacitive coupling effect to bootstrap the gate voltage of the driving TFT twice to improve the insufficient field-effect mobility of the a-Si:H TFT without the need to enlarge the driving TFT. To investigate the driving capability of an a-Si:H TFT varying with the gate bias, a simulation model, based on the measured transfer curves of an a-Si:H TFT, is developed. Based on the specifications of 5.9-in panel with full high-definition resolution and 60 Hz frame rate, gate drivers with different structures are fabricated and compared. The experimental results demonstrate that the rising and the falling time of the output waveform generated from the gate driver with PBM are 45.21% and 32.04% shorter than those of the conventional gate driver. Furthermore, under a doubling of loadings, a 50 kHz clock frequency, and operation at -20 °C, the proposed PBM improve the performance of a gate driver. During an accelerated lifetime test at 85 °C, the gate driver with PBM can generate stable output waveforms for 864 h, verifying its long-term reliability.
All Science Journal Classification (ASJC) codes
- Control and Systems Engineering
- Electrical and Electronic Engineering