Reconfigurable Gaussian filtering TSP readout circuit for Flexible AMOLED Display

With the rising demand for new form-factor displays, mobile devices with flexible panels have been increasingly commercialized. These flexible displays introduce significant parasitic capacitance, leading to substantial external noise coupling into the touch screen panel (TSP). This paper presents a reconfigureble Gaussian filtering TSP readout circuit, designed to adaptively attenuate external noises. It operates with a discrete-time analog processing architecture where a 2<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup>-generation current conveyor (CCII) is employed to sense the TSP capacitance as well as implement Gaussian filter coefficients. The operating clock for generating Gaussian coefficients is effectively implemented using a circular shift register with reconfigurable length. The readout circuit, designed using 350-nm process technology, achieves an out-of-band noise attenuation of 33dB.