Fingerprint detection circuit and method, electronic device

A fingerprint detection method, comprising:

• applying an excitation signal to a finger so as to generate ridge capacitors and valley capacitors;
• generating a first voltage or a second voltage by a collecting unit according to a regulation voltage, a capacitance value of one of the ridge capacitors and a capacitance value of one of the valley capacitors;
• amplifying the first voltage and the second voltage with a predetermined factor by a processing module;
• calculating a difference between an amplified first voltage and an amplified second voltage by the processing module;
• determining whether the difference is greater than or equal to a predetermined threshold by the processing module;
• when the difference is greater than or equal to the predetermined threshold, calculating the capacitance value of one of the ridge capacitors according to the first voltage and calculating the capacitance value of one of the valley capacitors according to the second voltage by the processing module;
• and
• when the difference is less than the predetermined threshold, adjusting at least one of an excitation voltage, the predetermined factor and the regulation voltage according to the predetermined threshold and the difference by the processing module, and configuring the collecting unit and the processing module with at least one adjusted parameter.

An electronic device, comprising a fingerprint detection circuit configured to apply an excitation signal to a finger so as to generate ride capacitors and valley capacitors, wherein the fingerprint detection circuit further comprises:

• a fingerprint collecting module comprising a plurality of collecting units, wherein each of the plurality of collecting units has a regulation voltage, and is configured to output a first voltage or a second voltage according to a capacitance value of one of the ridge capacitors, a capacitance value of one of the ridge capacitors, and the regulation voltage;
• and
• a processing module connected with the fingerprint collecting module, and configured to amplify the first voltage and the second voltage by a predetermined factor, to calculate a difference between an amplified first voltage and an amplified second voltage, and to determine whether the difference is greater than or equal to a predetermined threshold;
• wherein;
• where the difference is greater than or equal to the predetermined threshold, the processing module is further configured to calculate the capacitance value of one of the ridge capacitors according to the first voltage, and to calculate the capacitance value of one of the valley capacitors according to the second voltage;
• and
• when the difference is less than the predetermined threshold, the processing module is further configured to adjust at least one of an excitation voltage, the predetermined factor and the regulation voltage according to the predetermined threshold and the difference, and to configure the fingerprint collecting module and the processing module using at least one adjusted parameter, in which the excitation voltage is a voltage magnitude of the excitation signal,