A Low-Power Single-Input Level Shifter for Oxide Thin-Film Transistors

A new level shifter circuit suitable for implementation using n-channel oxide thin-film transistors (TFTs) is reported. This level shifter is designed to convert a single 10 V input signal into a 20 V output signal. In order to raise the output voltage up to
V
_DD
in spite of the large zero-
V
_GS
current of the oxide TFT, negative
V
_GS
is applied to the pull-down TFTs. Simulation and fabrication results show that the level shifter operates correctly with oxide TFTs and that the power consumption is as low as 0.2 mW at an input signal frequency of 10 kHz.