Digital preamplifier for MEMS microphone

Abstract

The invention relates to a digital preamplifier for an MEMS microphone, which comprises an Sigma Delta modulator and an MEMS polarization voltage generation module, wherein a first-stage integrator ofthe Sigma Delta modulator adopts a structure of a continuous time integrator, and various stages of integrators after the second stage adopt a structure of a switched-capacitor integrator; an input end of the continuous time integrator adopts a gate differential input circuit; and a wake source of the gate differential input circuit is connected with an integrating resistor and a feedback currentof the continuous time integrator respectively. The digital preamplifier meets the requirement of a new-generation advanced audio system on the input end, greatly promotes the anti-jamming ability ofthe conventional analog signal transmission path, improves the transmission quality of analog signals, and reduces physical space and design cost.

Description

technical field [0001] The invention relates to the field of MEMS audio sensors, in particular to a digital preamplifier used for MEMS microphones. Background technique [0002] An audio sensor (also known as a microphone) is a device that converts an external audio signal into a weak electrical signal. The design of traditional microphones is analog. A series of analog devices complete the amplification, modulation and synthesis of electrical signals. In most cases, the analog signals are converted into digital signals through analog-to-digital conversion for subsequent processing. In analog technology, due to the poor anti-interference ability of analog signal itself, it is inevitably affected by radio frequency, electromagnetic interference and power supply noise, which makes the quality of the signal degrade on the transmission path. In order to ensure qualified signal quality, a lot of additional design costs are required , physical space and design time. [0003] The...

AI Technical Summary

Problems solved by technology

In analog technology, due to the poor anti-interference ability of analog signal itself, it is inevitably affected by radio frequency, electromagnetic interference and power supply noise, which makes the quality of the signal degrade on the transmission path. In order to ensure qualified signal quality, a lot of additional design costs are required , physical space and design time

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