Amplifier for measuring 1MHz common mode rejection ratios of high-resistance high-voltage differential probe

Abstract

Disclosed is an amplifier for measuring 1MHz common mode rejection ratios of a high-resistance high-voltage differential probe. The amplifier comprises a pre-amplification unit, a frequency-selective amplification unit and two independent direct current supply voltage, wherein the two independent direct current supply voltage is connected with the pre-amplification unit and the frequency-selective amplification unit respectively and used for independently supplying power for the pre-amplification unit and the frequency-selective amplification unit respectively; the pre-amplification unit is used for providing preceding stage amplification times with preset ranges and amplifying signals and noises which are buried in noises; the frequency-selective amplification unit is connected with the pre-amplification unit and comprises an LC frequency-selective network and an amplification unit, the resonance centre frequency of the LC frequency-selective network is designed to be 1MHz, the amplification unit is composed of triodes, and the frequency-selective amplification unit is used for further amplifying 1MHz useful signals obtained by filtering. According to the amplifier for measuring the 1MHz common mode rejection ratios of the high-resistance high-voltage differential probe, the technical problem that common mode output voltage at high attenuation stage 1MHz frequency points of the high-resistance high-voltage differential probe can not be directly measured in prior art is solved.

Description

technical field [0001] The invention relates to an amplifier, in particular to an amplifier for measuring the 1MHz common-mode rejection ratio of a high-resistance high-voltage differential probe. Background technique [0002] Common mode rejection ratio is one of the key parameters reflecting the performance of high-impedance high-voltage differential probes. , ×1000), according to the requirements of the technical specification, it is necessary to give the measurement results of the common mode rejection ratio of the high-impedance high-voltage differential probe at 50Hz (60Hz), 1kHz, 10kHz, 100kHz, and 1MHz frequency points. At present, the high-impedance standard source can output sine wave frequency up to 1MHz and the output amplitude is the largest, only FLUKE5700A, and its output level capabilities at different frequency points are shown in Table 1. When measuring the common-mode rejection ratio of the high-impedance high-voltage differential probe at the high-attenu...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide an amplifier for measuring the 1MHz common-mode rejection ratio of a high-impedance high-voltage differential probe, so as to solve the technical problem in the prior art that the high-attenuation level 1MHz common-mode output voltage of a high-impedance high-voltage differential probe cannot be directly measured

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