In-Panel 31.17dB 140kHz 87μW Unipolar Dual-Gate In-Ga-Zn-O Charge-Sense Amplifier for 500dpi Sensor Array on Flexible Displays

In this paper a charge sense amplifier (CSA) using a 5um In-Ga-Zn-O transistor technology on 15um thick flexible substrate is presented for readout of a 500dpi fingerprint sensor array targeting direct integration with active matrix organic light emitting displays (AMOLED). The CSA achieves a linear input range of 0.8V for rail to rail output at VDD=15V. The CSA comprises of a high gain and stable dual-ended output dual-stage amplifier. The n-type load is driven by a dual-stage buffer and start-up circuit to increase the performance and ensure stability. The amplifier operates down to 6V supply voltage. It achieves 31.17dB DC-gain, 140kHz gain-bandwidth, 53$°$ phase margin and dissipates 87uW at 15V. The footprint of the CSA is 0.3mm2and enables 1fps readout of 1 megapixel 500dpi sensor array.keywords: Thin film transistors,Logic gates,Resistance,amplifier,Dielectrics,igzo,Sensor arrays,Gain,metal-oxide,amoled,dual gate,csa,display,imager,in-panelstatus: publishe