This disclosure provides systems, methods and apparatus for a controller configured to switch operation of a fingerprint sensor among operational modes. In one aspect, a fingerprint sensor may switch from operating in a first operational mode to a second operational mode based on one or more characteristics of fingerprint image data generated with the fingerprint sensor operating in the first operational mode. One of the first operational mode or the second operational mode may be a capacitive sensing mode, and the other may be an ultrasonic sensing mode.