Small signal amplification device

Abstract

The invention discloses a small signal amplification device, which solves the problem that an existing small signal amplification device is loud in noise, complex in circuit and high in cost. The device comprises a power processing unit and a signal amplification filter unit, wherein the signal amplification filter unit comprises first and second emitter followers, a first-stage amplifier, a second-stage amplifier, a third-stage amplifier, a band-pass filter and first and second wave traps; the first emitter follower receives a small signal and outputs the small signal to the first-stage amplifier, the band-pass filter filters the signal output by the first-stage amplifier, the second-stage amplifier receives a filtered output signal, the first wave trap filters interference of the signaloutput by the second-stage amplifier, the second wave trap filters the interference of the signal output by the first wave trap, the third-stage amplifier receives the signal output by the second wavetrap, and the second emitter follower receives the signal output by the third-stage amplifier and outputs an amplified signal; and the power processing unit supplies power to the signal amplificationfilter unit. The small signal amplification device achieved by the invention is good in cost performance, high in signal-to-noise ratio and strong in portability.

Description

technical field [0001] The invention relates to the electrical field, in particular to a small signal amplifying device. Background technique [0002] With the wide application of sensors, various weak and small signals output by sensors, such as weak light detection, small displacement detection, micro temperature difference detection, etc., have attracted more and more attention. The control signals obtained from various sensors are generally only a few mV or less, and any small vibration or electromagnetic interference around and ground noise may cause large fluctuations in the measurement results, resulting in reduced measurement accuracy. Because the signal is very weak, it must be amplified before it is measured. The noise introduced by the existing operational amplifier and sampling device may be dozens or even hundreds of times of the signal to be detected, so ordinary amplifiers cannot be directly selected, otherwise The noise of the amplifier itself can swamp the ...

AI Technical Summary

Problems solved by technology

[0003] The invention provides a small signal amplifying device, which solves the problems of the existing small signal amplifying device such as large noise, complex circuit, difficult debugging and high cost

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