Voltage converting apparatus and fingerprint detecting system

Abstract

The embodiments of the invention provide a voltage converting apparatus and a fingerprint detecting system. The voltage converting apparatus includes three input ends, two capacitors and two output ends. The two output ends are respective disposed at two ends of one of the capacitor. At the first moment, the apparatus is in a charging state and charges the two capacitors. At a second moment after the first moment, the apparatus is in a first discharging state, the two capacitors are in series connection to an input end power supply. At a third moment after the first moment, the apparatus is at a second discharging moment, the two capacitors are in series connection and have one ends grounded. According to the embodiments of the invention, the voltage converting apparatus and the fingerprint detection system use less capacitors to achieve the floating ground of a power supplying voltage. The voltage converting apparatus can be better integrated to a circuit or be encapsulated inside a chip, can be used to provide a power supply voltage to the fingerprint chip, increases the performances of the entire fingerprint chip and at the same time reduces reliance on peripheral devices, and increases the reliability of the entire system.

Description

technical field [0001] The present application relates to the technical field of biometric identification, in particular to a voltage conversion device and a fingerprint detection system. Background technique [0002] As mobile phone manufacturers continue to increase the demand and reliability of fingerprint modules placed on the front, fingerprint chips need to support higher and higher cover thicknesses. Some mobile phone manufacturers require the fingerprint chip to support the hidden fingerprint (UnderGlass) for the sake of the appearance and waterproof of the mobile phone. Due to the limitation of mobile phone battery voltage, the power supply voltage of fingerprint chips is generally 2.8-3.3V. However, under this voltage, it is difficult to guarantee the performance of the capacitive fingerprint chip, and effectively increasing the coding voltage becomes a key factor in its performance. [0003] Capacitive fingerprint chips generally use an inductive boost circuit t...

AI Technical Summary

Problems solved by technology

However, because it uses an inductor as a boost device, it cannot be integrated into an integrated circuit. At the same time, due to the size limitation, the inductor is not conducive to packaging into the chip, and if more capacitors are used, the size of the integrated circuit will increase.

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