Fingerprint Sensors and Terminal Devices

Abstract

The present application discloses a fingerprint sensor and a terminal device, including: the first driving circuit, configured to generate a periodic driving signal according to a periodic first input signal, and the first input signal and the driving signal The period is the same as the predetermined period; each second driving circuit corresponds to a column voltage integrator, and each second driving circuit is used to generate a column selection signal according to the second input signal, and the column selection signal is used to control the corresponding The working state of a column voltage integrator; wherein, when the second input signal is at a low level, the column selection signal is the second voltage, and when the second input signal is at a high level, the column The selection signal is the first voltage; each voltage integrator of the N column voltage integrators is used to receive the drive signal and the column selection signal generated by the corresponding second drive circuit, according to the drive signal and the column selection signal The selection signal charges or integrates the fingerprint capacitor.

Description

technical field [0001] The embodiments of the present application relate to the field of fingerprint detection, and more specifically, to a fingerprint sensor and a terminal device. Background technique [0002] Existing fingerprint detection schemes include capacitive fingerprint detection schemes, which can be divided into mutual-capacity coding and self-capacity coding according to the type of coding. Among them, the self-capacitance coding scheme has great advantages in cost and power consumption compared with the mutual capacitance coding scheme. However, since the switch of the self-capacity coding is a Metal Oxide Semiconductor (MOS) tube inside the chip , because the withstand voltage of the MOS tube is not high, so the size of the input signal is limited, and the signal-to-noise ratio (Signal-to-Noise Ratio, SNR) cannot be improved by increasing the input voltage. Therefore, a fingerprint sensor is needed. It can improve the SNR of the self-contained coding method....

AI Technical Summary

Problems solved by technology

Among them, the self-capacitance coding scheme has greater advantages in cost and power consumption than the mutual-capacity coding scheme. However, since the switch of the self-capacity coding is a Metal Oxide Semiconductor (MOS) tube , because the withstand voltage of the MOS tube is not high, so the size of the input signal is limited, and the signal-to-noise ratio (Signal-to-Noise Ratio, SNR) cannot be improved by increasing the input voltage. Therefore, a fingerprint sensor is needed. Can improve the SNR of the self-contained coding method

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