A Sweeping Mode CMOS Capacitive Fingerprint Sensor Chip

Abstract

In this paper, a sweeping mode capacitive sensor chip for fingerprint acquisition is presented. Based on capacitive fingerprint sensing, sweep capacitive sensor structure and readout circuit are proposed to grab the induced capacitance by the finger directly touched on the sensor plate. A test chip of 8×128 capacitive fingerprint sensor array is implemented in a standard 0.35-μm CMOS technology. Including the sensor array and peripheral digital control circuit, the chip area is 7307.1μm×748μm.