Fingerprint Detecting Circuit and Fingerprint Identification System

A fingerprint identification system, utilized for fingerprint identification, comprising:

• a plurality of fingerprint detecting circuits, each fingerprint detecting circuit comprising:
• a first conductive layer;
• a second conductive layer;
• an inverting amplifier, comprising:
• a single input terminal coupled to the first conductive layer;
• and an output terminal coupled to the second conductive layer;
• and
• a switching unit, configured for establishing a direct current (DC) operating point of the inverting amplifier, wherein a terminal of the switching unit is coupled to the input terminal of the inverting amplifier, and another terminal of the switching unit is coupled to the output terminal of the inverting amplifier;
• a fingerprint determining module, coupled to the plurality of fingerprint detecting circuit, configured to determine whether each fingerprint detecting circuit corresponds to a finger ridge or a finger valley.

A fingerprint detecting circuit, comprising:

• a first conductive layer for forming a sensing capacitance with a finger;
• a second conductive layer;
• an inverting amplifier, comprising an input terminal coupled to the first conductive layer;
• and an output terminal coupled to the second conductive layer;
• and
• a switching unit, wherein a terminal of the switching unit is coupled to the input terminal of the inverting amplifier, and another terminal of the switching unit is coupled to the output terminal of the inverting amplifier.