Compact 8-bit Digital-to-Analog Converter Using Low-Temperature Poly-Si Oxide Thin-Film Transistors

We propose an 8-bit digital-to-analog converter (DAC) using only thin-film transistors (TFTs), eliminating resistors and capacitors to reduce size and power consumption. The proposed DAC is designed using low-temperature poly-Si oxide (LTPO) TFTs based on an inverter concept. Short channel length LTPO TFTs, incorporating $1.5~\mu $ m LTPS and $2~\mu $ m a-IGZO TFTs, were used, with the LTPS TFT exhibiting field-effect mobility of 101 cm2/V $\cdot $ s and the a-IGZO TFT exhibiting 7.5 cm2/V $\cdot $ s, respectively. This 8-bit LTPO DAC occupies only 0.023 mm2 and demonstrates a minimal power consumption of $9.27~\mu $ W at the supply voltage of 3 V.