ANALOG FRONT END CIRCUIT FOR USE WITH FINGERPRINT SENSOR, AND DEVICE HAVING THE SAME

摘要

A sensing read-out circuit includes an amplifier circuit that converts a charge output from a sensing line of a sensor into a first voltage, another amplifier circuit that converts a charge output from another sensing line into a second voltage, another amplifier circuit that generates a first amplified voltage by amplifying a difference between the first voltage and the second voltage, an analog-to-digital converter that converts the first amplified voltage into a digital signal, a first mixer that generates a second mixed signal by mixing the first digital signal and an in-phase clock signal, a second mixer that generates a second mixed signal by mixing the first digital signal and a quadrature-phase clock signal, a first filter that generates an in-phase signal by performing low-pass filtering on the first mixed signal, and a second filter that generates a quadrature-phase signal by performing low-pass filtering on the second mixed signal.