Voice sensing device

Abstract

A voice sensing device is provided, comprising a circuit board, a bias voltage source deployed on the circuit board, and a system on chip. The system on chip is deployed on the circuit board, comprising a first module, a second module and a third module. The first module comprises a first sensor coupled to the first input end and the bias voltage source for sensing a first physical parameter and a second physical parameter. The second module comprises a second sensor coupled to the second input end for sensing the first physical parameter, wherein the second sensor is insensitive to the second physical parameter. The third module comprises an amplifier having a first input end, a second input end, and an output end, wherein the output end of the amplifier outputs a difference of the first and second input ends.

Description

technical field [0001] The invention relates to a microphone preamplifier, in particular to a circuit structure capable of eliminating self-interference. Background technique [0002] figure 1 Represents a traditional microphone amplifier circuit. An amplifier 150 is implemented on an integrated circuit 160 and has a first input (+), a second input (-) and an output. The integrated circuit 160 has a contact 102 for coupling external signals to the amplifier 150 . At the same time, the first input terminal is biased by a bias resistor 130 and a reference voltage source 140 located in the integrated circuit. A microphone box 120 is coupled between a bias voltage source 110 and the contact 102 . The output terminal of the amplifier 150 is connected to the second input terminal (−), and outputs the preamplified result (represented as Vout) of the microphone box 120 . The microphone box 120 can be an electret condenser microphone (ECM), which includes a movable film and a fi...

AI Technical Summary

Problems solved by technology

Due to the circuit structure, the quality of the microphone preamplifier will be seriously affected

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