Abstract: A fingerprint sensor includes an array of fingerprint sensing elements; analog-to-digital (A/D) converters having a controllable range; a scanner to perform sequential A/D conversions of predetermined ones of the array of fingerprint sensing elements; and a range determining and setting circuit for controlling the range of the A/D converters based upon prior A/D conversions to thereby provide enhanced conversion resolution. A plurality of A/D converters are preferably used for simultaneously converting analog signals from a corresponding plurality of fingerprint sensing elements. The A/D converters may include at least one reference voltage input for permitting setting of first and second points of the range. The range scale determining and setting circuit may generate a histogram based upon prior A/D conversions. In addition, the range scale determining and setting circuit may set a default range for initial ones of the fingerprint sensing elements.