Capacitive fingerprint sensor

Embodiments of the present disclosure hereinafter provide a capacitive fingerprint sensor. The capacitive fingerprint sensor includes: an integrator, a trigger and a base cancelling circuit; where the integrator is configured to store charges from a fingerprint capacitor to generate an output signal...

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Bibliographic Details
Main Authors Zhan, Chang, Pi, Tao, Li, Zhouqun, Zhang, Mengwen
Format Patent
LanguageEnglish
Published 23.07.2019
Subjects
CALCULATING
COMPUTING
COUNTING
PHYSICS
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Summary:Embodiments of the present disclosure hereinafter provide a capacitive fingerprint sensor. The capacitive fingerprint sensor includes: an integrator, a trigger and a base cancelling circuit; where the integrator is configured to store charges from a fingerprint capacitor to generate an output signal and transfer the output signal to the trigger, the trigger is configured to trigger the base cancelling circuit to generate a base cancelling signal and output the base cancelling signal to the integrator if the output signal exceeds a predetermined threshold, and the base cancelling signal is used to adjust the output signal of the integrator to fall within the predetermined threshold. In this way, the integrator is prevented from simply coming to saturation, and thus a dynamic range of the integrator is increased.
Bibliography:Application Number: US201715694755