A Novel Gate Driver Working Under Depletion Mode Oxide TFTs Using Low-Temperature Poly-Si Oxide TFTs

We report a novel gate driver integrated by low-temperature poly-Si oxide (LTPO) thin-film transistors (TFTs). The proposed gate driver consists of four p-type low-temperature polycrystalline silicon (LTPS) TFTs and two n-type amorphous indium gallium zinc oxide (a-IGZO) TFTs. Dual-gate (DG) a-IGZO TFTs, having high drain currents and excellent reliability, are utilized. The fabricated gate driver operates with a pulse width of
$1~\mu \text{s}$
corresponding to operating speed of 500 kHz at voltage swing of 15 V. Also, the proposed LTPO gate driver works well without malfunction with strong depletion mode a-IGZO TFTs having threshold voltage of −5.5 V. It is exhibited that the ripples, which appear when a-IGZO TFTs have negative threshold voltage, are perfectly removed by regulating two input DC signals.