Fingerprint identification system and electronic device

An electronic device, comprising:

• an operating circuit;
• and
• a fingerprint identification system, which comprises:
• a first pixel circuit, including a contact layer and a shielding layer, wherein the contact layer is over the shielding layer and form a first parasitic capacitance;
• a first sensing circuit, coupled to the contact layer of the first pixel circuit, the first sensing circuit being used for sensing a contact capacitance due to finger contact and outputting a first output signal;
• a second pixel circuit, including, from top to bottom, a contact layer, a shielding layer, a first metal layer and a second metal layer, wherein the contact layer and the shielding layer of the second pixel circuit form a second parasitic capacitance, and the first metal and the second metal form a third parasitic capacitance;
• a second sensing circuit, coupled to the first metal layer of the second pixel circuit, the second sensing circuit being used for outputting a second output signal, wherein the first output signal is related to the first parasitic capacitance and unrelated to the third parasitic capacitance;
• and the second output signal is related to the third parasitic capacitance and unrelated to the second parasitic capacitance;
• and
• a differential amplifier circuit, coupled to the first sensing circuit and the second sensing circuit, the differential amplifier circuit being used for amplifying a difference between the first output signal and the second output signal to generate an amplified output signal.