A new Polysilicon TFT capacitive fingerprint sensor with advanced mismatch compensation

Low temperature poly-silicon thin film transistors (LTPS TFT) technology is very suitable for low cost fingerprint sensor. In this paper, a new LTPS TFT capacitive sensor is presented. The proposed sensing scheme is based on charge sensitive amplifiers using correlated double sampling techniques (CDS) for offset voltage cancellation. Simulation results exhibit that the random offset voltage is successfully compensated.