Design and Implementation of 160×192 Pixel Array Capacitive-Type Fingerprint Sensor

Abstract

The application specific integrated circuit implementation of a capacitive fingerprint sensor system-on-chip (SOC), which embeds a 32-bit microcontroller for performing an identification algorithm, is described for user authentication on small, thin, and portable equipment. The SOC is composed of 160 × 192 array cells with a sensor detection circuit and an embedded 32-bit reduced instruction set computer (RISC) microcontroller. The proposed sensor detection circuit increases the voltage difference between a ridge and valley about 80% more than conventional circuits and minimizes an electrostatic discharge influence by applying an effective isolation structure. The 32-bit RISC microcontroller is embedded by a latch base for low power and low complexity. The test chip was fabricated on a 0.35 μm standard complementary metal oxide semiconductor 1-poly 4-metal process.