SELF-CAPACITIVE FINGERPRINT SENSOR WITH ACTIVE AMPLIFIED PIXELS

摘要

A fingerprint sensor device (100) is provided. The fingerprint sensor device (100) includes a substrate (104) and a sensor chip (102) disposed over the substrate (104). The sensor chip (102) includes an array of sensor pixels (108) configured to generate fingerprint data by sensing ridges and valleys of a surface of a finger (101) contacting the fingerprint sensor device (100). Each sensor pixel (108) includes a single sensor electrode (112) and an amplifier (122) having an inverting terminal electrically connected to the sensor electrode (112) and a non-inverting terminal electrically connected to a drive signal. The drive signal generates electric fields between the sensor electrode (112) and at least one of the ridges and valleys of the surface of the finger contacting the fingerprint sensor device (100) to generate a variable capacitor (130) having a variable capacitance based at least partly on a distance between the sensor electrode (112) and the at least one of the ridges and valleys of the finger (101).