Wideband and low-noise differential application circuit for measuring weak signal

Abstract

The invention relates to a wideband and low-noise differential application circuit for measuring a weak signal. The amplification circuit comprises a first-stage amplification circuit, a second-stage amplification circuit and a third-stage amplification circuit which are sequentially coupled and connected; both the first-stage amplification circuit and the third-stage amplification circuit are proportional differential amplification circuits; the second-stage amplification circuit is a high-pass filter differential amplification circuit; the first-stage amplification circuit comprises a first resistor, a second resistor, a third resistor, a first integrated operation amplifier and a second integrated operation amplifier; the second-stage amplification circuit comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, a second capacitor and a third integrated operation amplifier; the third-stage amplification circuit comprises an eighth resistor, a ninth resistor and a fourth integrated operation amplifier. The wideband and low-noise differential application circuit for measuring the weak signal is a wideband and low-noise amplification circuit provided for the shortages of a weak signal output detecting circuit of a marine sensor; the amplification circuit is capable of effectively amplifying nanometer-stage weak signals within the wideband range of 0.1Hz to 10MHz.

Description

Technical field [0001] The invention relates to a weak signal detection technology, in particular to a wide-band, low-noise differential amplifier circuit for weak signal measurement. The circuit can effectively amplify the weak signal output by the front sensor of an electromagnetic current meter, and can also be used It is used to measure the noise floor level in the frequency domain of a variety of sensor materials. Background technique [0002] At present, in the research and development of ocean current measuring instruments, the electromagnetic ocean current meter uses the geomagnetic field as the excitation field source, so the device does not need to design the emission source, making the front-end probe lighter. Compared with other ocean current measurement equipment, it is faster and more convenient, and is suitable for parameter measurement in a variety of marine environments. For example, the article "Development of a throwaway ocean current electric field profiler" ...

AI Technical Summary

Problems solved by technology

[0004] The invention mainly aims at the shortcomings of narrow frequency band and high noise in the detection circuit of the weak signal output by the marine sensor, and provides a wide-band and low-noise amplifying circuit. This amplifying circuit can perform nanoscale (nV) Effective amplification of weak signals with low self-noise level

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