Differential signal amplitude detection circuit

Abstract

The invention discloses a differential signal amplitude detection circuit. Grid electrodes of a first NMOS tube and a second NMOS tube are connected with a negative input end and a positive input end. Source electrodes of the first NMOS tube and the second NMOS tube are connected and are grounded through a first constant current source. Grid electrodes of a third NMOS tube and a fourth NMOS tube are connected with the positive input end and the negative input end. Source electrodes of the third NMOS tube and the fourth NMOS tube are connected and are grounded through a second constant current source. Drain electrodes of the first NMOS tube and the third NMOS tube are connected and are connected with a power supply through a first resistor. Drain electrodes of the second NMOS tube and the fourth NMOS tube are connected to form a first connection point and are connected with the power supply through a second resistor. A connection point between a third resistor and a fourth resistor is connected with grid electrodes of a fifth NMOS tube and a sixth NMOS tube. Source electrodes of the fifth NMOS tube and the sixth NMOS tube are connected and are grounded through a third constant current source. Drain electrodes of the fifth NMOS tube and the sixth NMOS tube are connected with the power supply through a fifth resistor and a sixth resistor. The connection point between the sixth NMOS tube and the sixth resistor is a second connection point. The first connection point and the second connection point are connected with two input ends of a comparator, and VOUT is output. The differential signal amplitude detection circuit has the advantages that the structure is simple, the power consumption is low, a small differential signal of a millivolt level can be effectively detected, and the application range is wide.

Description

technical field [0001] The invention relates to the technical field of analog signal processing and communication, in particular to a differential signal amplitude detection circuit. Background technique [0002] As a basic analog circuit, the differential signal amplitude detection circuit is widely used in data sampling. In communication systems, it is often necessary to judge whether the normal transmission signal has been interrupted as a system alarm condition, or to turn on the sleep mode to save power consumption. [0003] When a high-speed signal is transmitted, it is generally a differential signal with a low differential amplitude. At this time, it is necessary to detect a small differential amplitude, sometimes even only a few millivolts. For example, the limiting amplifier in the 10GSFP+ optical module, the laser driver and In the 10G multiplexing and demultiplexing chips, it is necessary to detect whether the input signal is lost, and the differential amplitude ...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is that the conversion efficiency of the existing differential signal amplitude detection circuit is low. problem with signal detection

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