Operating method for a fingerprint sensing device and fingerprint sensing system

A fingerprint sensing system comprising:

• a fingerprint sensing device comprising, a high-voltage input terminal and a low-voltage input terminal;
• and
• a power supply circuit coupled to the high-voltage input terminal and the low-voltage input terminal of the fingerprint sensing device, and supplying a first voltage, a second voltage, a third voltage and a fourth voltage, wherein the first voltage is greater than the second voltage, and the third voltage is greater than the fourth voltage;
• wherein in a scan phase of the fingerprint sensing device, the power supply circuit provides the first voltage to the high-voltage input terminal and provides the second voltage to the low-voltage input terminal to cause a first voltage difference between the high-voltage input terminal and the low-voltage input terminal;
• in a read phase of the fingerprint sensing device, the power supply circuit provides the third voltage to the high-voltage input terminal and provides the fourth voltage to the low-voltage input terminal to cause a second voltage difference between the high-voltage input terminal and the low-voltage input terminal;
• and
• the first voltage difference is greater than the second voltage difference.

A fingerprint sensing device comprising:

• multiple sensors;
• and
• a high-voltage input terminal and a low-voltage input terminal, wherein the high-voltage input terminal and the low-voltage input terminal are for coupling to a power supply circuit that supplies power to the fingerprint sensing device for sensing a fingerprint by the multiple sensors;
• wherein the fingerprint sensing device comprises a scan phase and a read phase while sensing the multiple sensors, a first voltage difference is between the high-voltage input terminal and the low-voltage input terminal during the scan phase, and a second voltage difference is between the high-voltage input terminal and the low-voltage input terminal during the read phase;
• wherein the first voltage difference is greater than the second voltage difference.