Fingerprint detection circuit

Fingerprint detection circuit

  • CN 205,139,939 U
  • Filed: 09/25/2015
  • Issued: 04/06/2016
  • Est. Priority Date: 09/25/2015
  • Status: Active Grant
First Claim
Patent Images

1. a fingerprint sensing circuit, is characterized in that, comprising:

  • Fingerprint detection electric capacity, one end couples finger;

    Detecting electrode, one end couples described fingerprint detection electric capacity;

    First selection unit, is suitable for selectivity by the first voltage or the second voltage-drop loading extremely described detecting electrode;

    Amplifier;

    5th switch, is suitable for the inverting input that described detecting electrode is coupled to described amplifier by selectivity;

    Second selection unit, is suitable for the normal phase input end that tertiary voltage or the 4th voltage are inputed to described amplifier by selectivity;

    Wherein, described first voltage and the second voltage are the different driving voltage of level, and described driving voltage is internal voltage driver;

    Described tertiary voltage and the 4th voltage are the different internal reference voltage of level.

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