Apparatus and method for reducing noise in fingerprint sensing circuits

Abstract

An apparatus for reducing noise in fingerprint sensing circuits is disclosed in one embodiment of the invention as including a fingerprint sensing area onto which a user can apply a fingerprint. An analog front end is coupled to the fingerprint sensing area and is configured to generate an analog response signal. An analog-to-digital converter (ADC) samples the analog response signal and converts the sample to a digital value, which may be received by a digital device such as a processor or CPU. To reduce the amount of the noise that is present in the analog response signal and therefore reflected in the digital value, the digital device may be shut down while the ADC is sampling the analog response signal.

1 . An apparatus for reducing noise in fingerprint sensing circuits, the apparatus comprising:
 a fingerprint sensing area onto which a user can apply a fingerprint;   an analog front end coupled to the fingerprint sensing area to generate an analog response signal;   an analog-to-digital converter (ADC) to sample the analog response signal and convert the sample to a digital value; and   a digital device to receive the digital value from the ADC, the digital device further configured to shut down while the ADC is sampling the analog response signal.