CN-224202565-U - High-linearity wide-range low-light detection circuit and device

Abstract

The utility model discloses a high-linearity wide-range micro-light detection circuit and a device, wherein the circuit comprises a micro-light detection sub-circuit, a logarithmic amplification sub-circuit and a linear amplification sub-circuit, the micro-light detection sub-circuit converts a detected micro-light signal into a logarithmic change current signal, the logarithmic amplification sub-circuit converts the logarithmic change current signal into a linear change voltage signal after current-voltage conversion and differential amplification, the linear amplification sub-circuit regulates the range of the voltage signal and outputs the voltage signal, and an external circuit or device obtains the light power of the detected micro-light signal according to the output voltage signal. The circuit realizes the detection of low light level with high linearity, wide range and high precision.

Inventors

• CHEN WEI
• GUO LEI
• TU WEI
• LUO HUI
• SHAO ZHEMING
• WANG HONGYONG
• WU YINGRUI
• XI WENQIANG
• HUANG XIONG
• DENG DAIZHU
• LV XINGJIE
• ZHENG JIAFENG

Assignees

• 中船泓洋科技(武汉)有限责任公司

Dates

Publication Date

20260505

Application Date

20250507

Claims (10)

1. 1. The high-linearity wide-range low-light detection circuit is characterized by comprising a low-light detection sub-circuit, a logarithmic amplifier sub-circuit and a linear amplifier sub-circuit; The micro-light detection sub-circuit converts the detected micro-light signal into a logarithmically-changed current signal, the logarithmically-changed current signal is converted into a linearly-changed voltage signal by the logarithmic amplification sub-circuit after current-voltage conversion and differential amplification, the range of the voltage signal is regulated by the linear amplification sub-circuit and output, and an external circuit or device obtains the light power of the detected micro-light signal according to the output voltage signal.
2. 2. The high linearity, wide range micro light detection circuit of claim 1, wherein the micro light detection sub-circuit comprises a photodiode PD; the logarithmic amplifying sub-circuit comprises a signal processing module and a biasing module; the signal processing module comprises an operational amplifier U1A, an operational amplifier U1B and an operational amplifier U2A, wherein the operational amplifier U1B provides bias voltage for the micro-light detector circuit, the operational amplifier U1A is differentially connected with the operational amplifier U2A, and the operational amplifier U1A and the operational amplifier U2A perform differential processing according to a current signal output by the micro-light detector circuit and an introduced reference current IREF to obtain two paths of linearly transformed voltage signals VBE1 and VBE2; The bias module provides bias voltage for the signal processing module.
3. 3. The high linearity wide range micro light detecting circuit according to claim 2, wherein the linear amplifying sub-circuit comprises an operational amplifier U2B, a resistor R6, a resistor R7 and a resistor R12, wherein the non-inverting input end of the operational amplifier U2B is connected with the voltage signal VBE1 through the resistor R6, the inverting input end of the operational amplifier U2B is connected with the voltage signal VBE2 through the resistor R7, the output end of the operational amplifier U2B outputs the regulated voltage signal, and the two ends of the resistor R12 are respectively connected with the inverting input end and the output end of the operational amplifier U2B.
4. 4. The high linearity wide range micro light detection circuit according to claim 3, wherein the circuit comprises a bias sub-circuit, the bias sub-circuit provides bias voltage for the linear amplifier sub-circuit, the bias sub-circuit comprises a resistor R8, a resistor R9, a resistor R10 and a resistor R11, the non-inverting input end of the operational amplifier U2B is connected with the reference voltage REF after passing through the resistor R9, the inverting input end of the operational amplifier U2B is grounded after passing through the resistor R10, two ends of the resistor R10 are grounded and connected with the non-inverting input end of the operational amplifier U2B respectively, and two ends of the resistor R11 are grounded and connected with the non-inverting input end of the operational amplifier U2B respectively.
5. 5. The high linearity wide range micro light detecting circuit according to claim 3, comprising a slope control sub-circuit for controlling the detecting precision of the output voltage signal relative to the detected micro light signal, wherein the slope control sub-circuit comprises a resistor R13, and two ends of the resistor R13 are respectively grounded and connected with the output end of the operational amplifier U2B.
6. 6. A high linearity wide range low light level detection device comprising the high linearity wide range low light level detection circuit of claim 1.
7. 7. The high linearity wide range micro light detection device of claim 6, wherein the micro light detection sub-circuit comprises a photodiode PD; the logarithmic amplifying sub-circuit comprises a signal processing module and a biasing module; the signal processing module comprises an operational amplifier U1A, an operational amplifier U1B and an operational amplifier U2A, wherein the operational amplifier U1B provides bias voltage for the micro-light detector circuit, the operational amplifier U1A is differentially connected with the operational amplifier U2A, and the operational amplifier U1A and the operational amplifier U2A perform differential processing according to a current signal output by the micro-light detector circuit and an introduced reference current IREF to obtain two paths of linearly transformed voltage signals VBE1 and VBE2; The bias module provides bias voltage for the signal processing module.
8. 8. The device of claim 7, wherein the linear amplifying sub-circuit comprises an operational amplifier U2B, a resistor R6, a resistor R7 and a resistor R12, wherein the non-inverting input end of the operational amplifier U2B is connected with the voltage signal VBE1 through the resistor R6, the inverting input end of the operational amplifier U2B is connected with the voltage signal VBE2 through the resistor R7, the output end of the operational amplifier U2B outputs the regulated voltage signal, and the two ends of the resistor R12 are respectively connected with the inverting input end and the output end of the operational amplifier U2B.
9. 9. The high linearity wide range micro light detecting device according to claim 8, wherein the high linearity wide range micro light detecting device comprises a bias sub-circuit, the bias sub-circuit provides bias voltage for the linear amplifying sub-circuit, the bias sub-circuit comprises a resistor R8, a resistor R9, a resistor R10 and a resistor R11, the non-inverting input end of the operational amplifier U2B is connected with a reference voltage REF after passing through the resistor R9, the inverting input end of the operational amplifier U2B is grounded after passing through the resistor R10, two ends of the resistor R10 are grounded and connected with the non-inverting input end of the operational amplifier U2B respectively, and two ends of the resistor R11 are grounded and connected with the non-inverting input end of the operational amplifier U2B respectively.
10. 10. The high linearity wide range micro light detecting device according to claim 8, comprising a slope control sub-circuit for controlling the detection precision of the output voltage signal relative to the detected micro light signal, wherein the slope control sub-circuit comprises a resistor R13, and both ends of the resistor R13 are respectively grounded and connected with the output end of the operational amplifier U2B.

Description

High-linearity wide-range low-light detection circuit and device Technical Field The utility model relates to the technical field of low-light level detection electronics, in particular to a high-linearity wide-range low-light level detection circuit and a device. Background The micro-light detection technology is a very important content in the field of micro-signal measurement, and is also one of key technologies in an optical communication network. Current common micro-light detection techniques include transimpedance amplification techniques and logarithmic micro-current amplification techniques. The transimpedance amplification technology has a narrow measurement range, a plurality of large resistors are required to be connected in parallel to realize range switching, switching errors are introduced in the range switching process, and measurement accuracy is affected. The logarithmic micro-current amplification technology does not need to perform range switching in the full range, so that the current measurement continuity is good, and the method is suitable for occasions where the current changes rapidly, but the accuracy of measuring extremely small current (below 10 －9 A) by the logarithmic micro-current amplification technology is difficult to meet the requirement. Therefore, the existing low-light detection technology is difficult to achieve both a wide measurement range and high precision. Disclosure of utility model The utility model aims to provide a high-linearity wide-range low-light detection circuit and a device thereof, so as to realize wide-range and high-precision detection of low light. In order to solve the technical problems, the utility model provides a high-linearity wide-range low-light detection circuit, which comprises a low-light detection sub-circuit, a logarithmic amplifier sub-circuit and a linear amplifier sub-circuit; The micro-light detection sub-circuit converts the detected micro-light signal into a logarithmically-changed current signal, the logarithmically-changed current signal is converted into a linearly-changed voltage signal by the logarithmic amplification sub-circuit after current-voltage conversion and differential amplification, the range of the voltage signal is regulated by the linear amplification sub-circuit and output, and an external circuit or device obtains the light power of the detected micro-light signal according to the output voltage signal. According to the above scheme, the micro-light detector circuit includes a photodiode PD; the logarithmic amplifying sub-circuit comprises a signal processing module and a biasing module; the signal processing module comprises an operational amplifier U1A, an operational amplifier U1B and an operational amplifier U2A, wherein the operational amplifier U1B provides bias voltage for the micro-light detector circuit, the operational amplifier U1A is differentially connected with the operational amplifier U2A, and the operational amplifier U1A and the operational amplifier U2A perform differential processing according to a current signal output by the micro-light detector circuit and an introduced reference current IREF to obtain two paths of linearly transformed voltage signals VBE1 and VBE2; The bias module provides bias voltage for the signal processing module. According to the scheme, the linear amplifying sub-circuit comprises an operational amplifier U2B, a resistor R6, a resistor R7 and a resistor R12, wherein the non-inverting input end of the operational amplifier U2B is connected with a voltage signal VBE1 through the resistor R6, the inverting input end of the operational amplifier U2B is connected with the voltage signal VBE2 through the resistor R7, the output end of the operational amplifier U2B outputs an adjusted voltage signal, and the two ends of the resistor R12 are respectively connected with the inverting input end and the output end of the operational amplifier U2B. According to the scheme, the bias circuit comprises a bias sub-circuit, wherein the bias sub-circuit provides bias voltage for the linear amplifier sub-circuit, the bias sub-circuit comprises a resistor R8, a resistor R9, a resistor R10 and a resistor R11, the non-inverting input end of the operational amplifier U2B is connected with a reference voltage REF after passing through the resistor R9, the inverting input end of the operational amplifier U2B is grounded after passing through the resistor R10, two ends of the resistor R10 are respectively grounded and connected with the inverting input end of the operational amplifier U2B, and two ends of the resistor R11 are respectively grounded and connected with the non-inverting input end of the operational amplifier U2B. According to the scheme, the micro-optical signal detection circuit comprises a slope control sub-circuit, wherein the slope control sub-circuit controls the detection precision of an output voltage signal relative to a detected micro-optical signal, and comprises a