Current comparator with hysteresis function

Abstract

The invention discloses a current comparator with a hysteresis function, belongs to the technical field of the current comparator under an integrated circuit and solves the problem that according a traditional current comparator, a uniform threshold current is employed, a response speed is too fast, so the sensitivity to noise mixed up with a peak current is caused, unnecessary overturn occurs in an output level and a final judgment result is influenced is solved. The current comparator comprises a threshold current control unit 1, a phase inverter INV0, a phase inverter INV1, NMOS transistors MN1-MN5, NMOS transistors MN9-MN10, a PMOS transistor MP3 and a current source Ipeak _current. When the peak current is mixed up with the noise, according to the traditional current comparator, the level is overturned relatively fast, while according to the current comparator with the hysteresis function, a response to the change of the peak current is relatively slow. A current threshold value is adaptively switched each time after the level is overturned.

Description

technical field [0001] The invention belongs to the technical field of current comparators under integrated circuits. Background technique [0002] At the receiving end of the optical fiber communication integrated circuit, it is necessary to convert the optical signal into a current signal through a photodiode, and then convert the current signal into a voltage signal through a transimpedance amplifier. The performance requirements of the transimpedance amplifier are high bandwidth, low noise, medium gain and fast response speed, and its output signal mixed with noise will be passed to the high-gain limiting amplifier. In order to make the limiting amplifier amplify the electrical signal that meets the level standard, a judgment circuit for input signal noise is added to the limiting amplifier. The judgment circuit will include a current comparator to accurately judge whether the input is noise or meets the level standard. The electrical signal realizes the closing and ope...

AI Technical Summary

Problems solved by technology

[0010]The purpose of the present invention is to solve the problem that the traditional current comparator adopts a unified threshold current, and because of the fast response speed, it is sensitive to the noise carried by the peak current, resulting in the output current Unnecessary inversion of the level will affect the final judgment result, and a current comparator with hysteresis function is provided

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