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 μm LTPS and 2 μm a-IGZO TFTs, were used, with the LTPS TFT exhibiting field-effect mobility of 101 cm²/V·s and the a-IGZO TFT exhibiting 7.5 cm²/V·s, respectively. This 8-bit LTPO DAC occupies only 0.023 mm² and demonstrates a minimal power consumption of 9.27 μW at the supply voltage of 3 V.