Bandwidth product trans-impedance amplifier and current-voltage conversion method

Abstract

The invention discloses a bandwidth product trans-impedance amplifier and a current-voltage conversion method, relates to the technical field of weak current signal detection, and solves the problem that in order to increase the value of gm, an existing trans-impedance amplifier inevitably causes increase of an input-stage bias current and increase of power consumption. The bandwidth product trans-impedance amplifier comprises a first-stage amplification circuit, a second-stage amplification circuit and an output circuit. The first-stage amplification circuit is used for amplifying and converting an input current under the action of negative feedback input impedance to obtain first output voltage. The second-stage amplifying circuit is electrically connected with the first-stage amplifyingcircuit. The second-stage amplification circuit is used for carrying out gain amplification on the first output voltage to obtain a second output voltage. The output circuit is electrically connectedwith the second-stage amplification circuit and is used for outputting target voltage. The bandwidth product trans-impedance amplifier provided by the invention is used for realizing high gain, highbandwidth and low input noise.

Description

technical field [0001] The invention relates to the technical field of weak current signal detection, in particular to a bandwidth product transimpedance amplifier and a current-voltage conversion method. Background technique [0002] The transimpedance amplifier is used as the first-stage amplification circuit for weak current signal detection, which requires high gain-bandwidth product and low input noise current spectral density. The performance of the transimpedance amplifier affects the sensitivity of the entire weak current signal detection system. At present, most of the commonly used broadband current amplifiers use diode-connected input transistors. To further expand the bandwidth of the amplifier, the only way to increase the transconductance g of the input transistor is m to lower the input impedance and push the dominant pole to higher frequencies. And in order to increase g m The value of the input stage will inevitably lead to an increase in the bias current...

AI Technical Summary

Problems solved by technology

[0003] The object of the present invention is to provide a kind of bandwidth transimpedance amplifier and current-voltage conversion method that can realize high gain, high bandwidth and low input noise, for solving existing transimpedance amplifier in order to improve g m The value of the input stage will inevitably lead to an increase in the bias current of the input stage, which will cause a problem of greater power consumption.

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