High-speed fully-differential noise reduction device for CMOS optical receivers

Abstract

The invention discloses a high-speed fully-differential noise reduction device for CMOS optical receivers. The noise reduction device comprises a low-noise trans-impedance amplifier which is used for converting a current signal output by a photoelectric detector into a voltage signal and preliminarily amplifying the voltage signal and has low equivalent input noise current, a single-ended to differential circuit which is used for realizing conversion from single-ended to differential output, increasing the circuit bandwidth, amplifying the voltage signal, effectively reducing equivalent input noise current introduced by a back-end circuit and eliminating common-mode noise introduced by a power supply and the like, a two-stage three-order differential limiting amplifier which adopts a staggered active feedback and capacitance degeneration circuit and is used for amplifying the voltage signal to a voltage level needed for a digital processing unit, and an output buffer stage which is used for converting an output differential voltage signal into a single-ended output voltage signal. On the premise of keeping the overall gain and bandwidth of the circuit, the introduced noise is reduced, and the sensitivity of optical receivers is improved.

Description

technical field [0001] The invention relates to the fields of optical fiber communication systems and optical interconnection, in particular to a high-speed full differential noise reduction device for CMOS optical receivers. Background technique [0002] In today's era of rapid development of network and information technology, the short-distance network communication technology with electrical interconnection as the main connection method gradually shows unavoidable shortcomings, mainly in low speed, large crosstalk, and high power consumption. Optical fiber communication technology can make up for this defect of electrical interconnection with its high speed, no crosstalk and good confidentiality. Therefore, in recent years, the application of optical fiber communication technology in short-distance and very short-distance network communication has attracted extensive attention. For example, between cabinets, between circuit boards and chips, and even between long-distan...

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Problems solved by technology

[0005] As one of the key parameters of the optical receiver, the sensitivity is closely related to the noise of the analog front-end circuit, so it is equally important to study the noise reduction technology of the high-speed optical receiver, but there is no good application in the CMOS optical receiver in the prior art The noise reduction device cannot meet the sensitivity requirements in practical applications

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