Amplifying circuit, photoelectric signal detection circuit, detection chip circuit and chip

Abstract

The invention discloses an amplifying circuit, a photoelectric signal detection circuit, a detection chip circuit and a chip. An adjustable RC circuit network is adopted to obtain the amplifying circuit, a transimpedance resistor converts a photocurrent signal into a voltage signal, the voltage signal is amplified by the variable gain amplifying circuit and then is subjected to secondary detectionby the envelope detection circuit, when an optical signal is relatively strong, envelope output of primary detection can be adopted, and when the optical signal is relatively weak, the envelope output of secondary detection is amplified again in the detection circuit, and the envelope output of secondary detection can be adopted. Through amplification of the variable gain amplifying circuit, band-pass filtering and variable gain are realized, and the size of an external optical signal is judged according to the amplitude of secondary detection. Different gains are achieved by adjusting the numerical value through RC, the stability of the gains and the linearity of current-voltage conversion are improved, band-pass filtering and low-frequency band-pass amplification are achieved, it is guaranteed that the system has high small signal gains and a large dynamic range, the circuit structure is simplified, and the cost is reduced.

Description

technical field [0001] The invention relates to the technical field of photoelectric detection, in particular to a photoelectric signal detection circuit with high sensitivity and wide dynamic range, a detection chip and a chip circuit. Background technique [0002] At present, the elevator light curtain is composed of four parts: the infrared transmitter and receiver installed on both sides of the elevator car door, the power box installed on the car top and the special flexible cable. There are multiple infrared emitting tubes in the transmitter, the number of infrared emitting tubes is 8, or 16, or 32; under the control of the microprocessor at the transmitting end, the transmitting and receiving tubes are opened in sequence, and the car door is scanned continuously from top to bottom area, when any beam of light is blocked, the control system immediately outputs a door-opening signal, the car door stops closing and opens in reverse, and the elevator door can be closed no...

AI Technical Summary

Problems solved by technology

At the receiving end, the receiving circuit designed by the linear amplification method is susceptible to the interference of ambient light and noise, and the circuit designed by the limiting amplifier method cannot detect the specific strength of the signal to judge the position of the gate.

[0004] When the data rate is very low, if the closed-loop automatic gain control is used, it will be difficult to adapt due to the inherent lower limit cut-off frequency; when the external optical signal changes quickly, and the system needs to respond quickly in real time, the closed-loop automatic gain control Due to the inherent loop settling time it is also difficult to accommodate

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