Design of Configurable CMOS Capacitive Fingerprint

Abstract

In this paper we propose a configurable CMOS capacitive fingerprint that has two configuration modes for charge detection in each cell pixel. The readout circuit can be configured to operate with/without analog-to-digital converter (ADC). One of the configuration modes utilize in-cell pixel comparator which provides an instant decision of the finger features (Ridge = 1 or Valley = 0). While, the other one uses a programmable gain amplifier (PGA) to provide the detected signal to an ADC. The simulation results show the difference between the output of both configurations.