Patent attributes
A capacitive fingerprint sensing device and method therein for noise detection are disclosed. The capacitive fingerprint sensing device comprises a plurality of sensing elements, each comprising a sensing structure and configured to sense a capacitive coupling between the sensing structure and a finger. The fingerprint sensing device further comprises sensing circuitry and timing circuitry configured to control a timing of a drive signal. The fingerprint sensing device is controllable to operate in a noise-detection mode and in a fingerprint mode. In the noise-detection mode, the fingerprint sensing device is configured to control the timing circuitry such that no drive signal is provided. The fingerprint sensing device senses a capacitive coupling between the finger and at least one sensing structure and provides a sensing signal indicative of the capacitive coupling between the finger and the sensing structures by means of said sensing circuitry.
