Thermal Sensor Using Poly-Si Thin-Film Transistor With Widened Detectable Temperature Range

We propose a thermal sensor using a poly-Si thin-film transistor (TFT) with widened detectable temperature range. The cell circuit is composed of one transistor and one capacitor. The cell capacitor is charged during initializing periods and discharged during holding periods, and the dropped voltages are measured during detecting periods. The temperature is detected because the discharge current is subject to the temperature dependence of the transistor characteristic. The detectable temperature is expanded to -10°C-140°C by adding multiple holding periods. We think that it is promising to integrate this thermal sensor in some applications using TFTs.