High-sensitivity microphone voice-code-words circuit

Abstract

The invention discloses a high-sensitivity microphone voice-code-words circuit, the high-sensitivity microphone voice-code-words circuit comprises an automatic gain control circuit, a microphone levelconversion circuit and a microprocessor, wherein a microphone signal is subjected to signal amplification and buffering and then transmitted to the automatic gain control circuit, the automatic gaincontrol circuit attenuates the microphone signal and then transmits one path to the microprocessor through a conversion interface and transmits the other path to a device interface through a control handle, the conversion interface comprises one Dt-Ypout port, and the control handle comprises one VIN MIC port; the automatic gain control circuit comprises an IN port, an amplifier U1, an amplifier U2, a triode Q, a QUT1 port and an OUT2 port, and the microphone level conversion circuit comprises a capacitor C6, a capacitor C7, a resistor R9 and a resistor R10. The high-sensitivity microphone voice-code-words circuit has high logicality, thus, an input signal transmitted by the circuit is steadier and more accurate, overall response speed of the circuit is fast, and sensitivity of the circuitis higher, moreover, adjustability effects of automatic gain is excellent, gain width is relatively wide, and the circuit is more suitable for the requirements of audio equipment interfaces.

Description

technical field [0001] The invention belongs to the field of signal processing, and more specifically relates to a high-sensitivity microphone vocoder circuit. Background technique [0002] As we all know, an automatic gain control (Automatic Gain Control, AGC) circuit is usually set in audio equipment (such as speakers, radios, etc.) to amplify the input signal, and the AGC circuit can adjust the gain of the amplifier according to the voltage range of the input signal. Automatic adjustment, so that when the input signal amplitude changes greatly, the voltage amplitude of the output signal is stable or changes within a small range. [0003] The function of the automatic gain control and the circuit is to keep the output voltage of the receiver constant or basically unchanged when the input signal voltage changes greatly. Specifically, when the input signal is very weak, the gain of the receiver is large, and the automatic gain control circuit does not work; when the input s...

AI Technical Summary

Problems solved by technology

[0006] First, the adjustment effect of the automatic gain is not good, especially when the low-frequency small signal is input, there are poor adaptability, slow response speed of the circuit, low receiving sensitivity, and errors in the self-adjustment ability;

[0007] Second, the logic of the connection between the automatic gain and the microphone circuit is not strong, and the degree of automation is not high, so that the input signal is transmitted to the microphone circuit after automatic gain, and then the input signal transmitted from the microphone circuit to the microphone and the device interface is not stable and accurate enough. , the response speed becomes slower and the sensitivity is poor

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