Emission Gate Driver With Five Low-Temperature Poly-Si Oxide TFTs Without Capacitor for Narrow-Bezel AMOLED Display

We report a highly simplified emission (EM) gate driver circuit for high resolution and narrow bezel active-matrix organic light emitting diode (AMOLED) display using low-temperature poly-Si oxide (LTPO) thin film transistors (TFTs). The proposed circuit consists of five TFTs, three low-temperature poly-Si (LTPS), and two oxide TFTs. The output signal can be controlled with variable pulse width by starting signal of different pulse width. The fabricated circuit operates well with depletion mode oxide TFTs having threshold voltage of–3.5 V. The output swing from 3 V to–7 V and peak-to-peak voltage of 10 V were used for the output measurement. The output signals with a different duty ratio of 10%, 50%, and 90% are demonstrated. The power consumption is only 41.5 mW when the duty ratio of EM signal is 90% at refresh rate of 120 Hz for a 4k (
$3840\times2160$
) AMOLED display.