Multi-path PD detection device

Abstract

The utility model provides a multi-path PD detection device which comprises a plurality of PD detection circuits and an MCU control chip, and each PD detection circuit is composed of a PD acquisition circuit, an analog switch circuit and an operational amplifier follower circuit. And the PD acquisition circuit sequentially comprises a capacitance limiting module, a PD input module, a resistance-capacitance module and a voltage following module, and is used for filtering, isolating and stabilizing the output signal of the photodiode. A plurality of PD signals are multiplexed by an analog switch and then are sequentially sent to an operational amplifier follower circuit, and finally efficient acquisition is realized through a small number of ADC (Analog to Digital Converter) interfaces. The device is modularized in structure, high in expandability, simple in structure, low in cost and excellent in real-time performance, has a large number of PD acquisition channels and a small number of ADC interfaces, and is suitable for realizing centralized acquisition of large-scale PD channels.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photoelectric detection, and particularly relates to a multi-channel PD detection device. BACKGROUND

[0002] In the existing photoelectric detection system, a photodiode (PD) acquisition circuit is usually composed of a reverse bias voltage source, a current limiting resistor, a PD device, a sampling resistor, a resistance-capacitance filter circuit and an operational amplifier following isolation circuit in series. When a reverse bias is applied to the PD to be detected, the output photocurrent is converted into a voltage signal through the sampling resistor, and then the interference harmonics are suppressed by a matching resistance-capacitance combination, and finally the operational amplifier following circuit is isolated to send the voltage signal into the ADC channel of the single-chip microcomputer for analog-digital conversion. This kind of scheme has simple structure and fast response speed, but each PD acquisition needs to occupy an ADC channel, and the expandability is limited.

[0003] With the increasing demand for real-time acquisition of hundreds of PD values, the number of ADC channels of the single-chip microcomputer has become a bottleneck for system expansion. If the detection mode of one PD-one ADC is still used, not only the parallel acquisition demand of more than one hundred channels cannot be met, but also a large amount of hardware resources will be wasted and the cost will rise sharply.

[0004] Therefore, there is an urgent need for a multi-channel PD detection solution that can not only collect a large number of channels in a centralized manner, but also effectively reduce the number of ADC interfaces and the overall cost. SUMMARY

[0005] The present application provides a multi-channel PD detection device to solve the problems of insufficient ADC channels, limited expansion and high cost in the traditional photoelectric detection system.

[0006] In a first aspect, the present application provides a multi-channel PD detection device, which comprises a plurality of PD detection circuits and an MCU control chip, the MCU control chip comprises a plurality of signal output ends and a plurality of ADC detection ends, each of the PD detection circuits comprises a plurality of PD acquisition circuits, an analog switch circuit and an operational amplifier following circuit.

[0007] The input end of the analog switch circuit comprises a plurality of PD value input ends and a plurality of control signal input ends.

[0008] The output end of each of the PD acquisition circuits is connected to the corresponding PD value input end of the analog switch circuit.

[0009] The signal output end of each of the MCU control chips is connected to the corresponding control signal input end of the analog switch circuit.

[0010] The output end of the analog switch circuit is connected to the input end of the operational amplifier following circuit.

[0011] An output end of the operational amplifier follower circuit is connected with an ADC detection end of the corresponding MCU control chip.

[0012] The PD acquisition circuit is used for acquiring a PD value of the to-be-tested photodiode, and the PD value is an efficiency of converting a light signal into an electric signal by the to-be-tested photodiode.

[0013] The analog switch circuit is used for connecting the corresponding PD acquisition channel and the ADC detection end of the corresponding MCU control chip in response to a control signal of the MCU control chip.

[0014] The operational amplifier follower circuit is used for isolating the analog switch circuit and the MCU control chip.

[0015] Optionally, each of the PD acquisition circuits comprises a capacitance limiting module, a PD input module, a resistance-capacitance module and a first voltage follower circuit module.

[0016] Therefore, an input end of the capacitance limiting module is connected with an output end of the bias voltage, and an output end of the capacitance limiting module is connected with an input end of the PD input module.

[0017] An output end of the PD input module is connected with an input end of the resistance-capacitance module.

[0018] An output end of the resistance-capacitance module is connected with an input end of the first voltage follower circuit module.

[0019] An output end of the first voltage follower circuit module is connected with the analog switch circuit.

[0020] The PD input module is used for converting a light signal into an electric signal by the to-be-tested photodiode and outputting a voltage value.

[0021] The capacitance limiting module is used for limiting a current passing through.

[0022] The bias voltage is used for providing a reverse bias voltage for the to-be-tested photodiode.

[0023] The resistance-capacitance module is used for suppressing interference harmonics.

[0024] The first voltage follower circuit module is used for isolating the PD input module and the analog switch circuit.

[0025] Optionally, the capacitance limiting module comprises a first filter capacitor, a current limiting resistor and a second filter capacitor.

[0026] An input end of the first filter capacitor is connected with an output end of the bias voltage, and an output end of the first filter capacitor is grounded.

[0027] The input end of the current limiting resistor is connected with the output end of the bias voltage, and the output end is connected with the input end of the second filter capacitor and the input end of the PD input module respectively;

[0028] The output end of the second filter capacitor is grounded.

[0029] Optionally, the PD input module comprises a to-be-measured photodiode and a sampling resistor;

[0030] The cathode of the to-be-measured photodiode is connected with the output end of the capacitance limiting module;

[0031] The anode of the to-be-measured photodiode is connected with the input end of the sampling resistor R2 and the input end of the resistance-capacitance module respectively;

[0032] The output end of the sampling resistor is grounded.

[0033] The to-be-measured photodiode is used for converting an optical signal into a photoelectric current;

[0034] The sampling resistor is used for obtaining a voltage signal according to the photoelectric current.

[0035] Optionally, the resistance-capacitance module comprises a matching resistor and a third filter capacitor;

[0036] The input end of the matching resistor is connected with the output end of the PD input module, and the output end is connected with the input end of the third filter capacitor and the input end of the first voltage follower circuit module respectively;

[0037] The output end of the third filter capacitor is grounded.

[0038] Optionally, the first voltage follower circuit module comprises a first voltage follower and a fourth filter capacitor;

[0039] The input end of the first voltage follower is connected with the output end of the resistance-capacitance module, and the output end is connected with the analog switch circuit;

[0040] The input end of the fourth filter capacitor is connected with the first voltage follower and a power supply input end respectively, and the output end is grounded.

[0041] Optionally, the analog switch circuit comprises an analog switch and a fifth filter capacitor, and the analog switch adopts a single-chip microcomputer control chip;

[0042] The input end of the fifth filter capacitor is connected with a power supply input end and the analog switch respectively, and the output end is grounded.

[0043] Optionally, the analog switch comprises a plurality of PD value input pins, a plurality of control signal input pins, an I / O pin, a VDD pin, an EN pin and a GND pin;

[0044] Each of the PD value input pins is connected with the output end of a corresponding PD acquisition circuit;

[0045] Each of the control signal input pins is connected with a signal output pin of the MCU control chip;

[0046] The input end of the fifth filter capacitor is connected with the VDD pin and the EN pin respectively, and the output end is grounded;

[0047] The VDD pin and the EN pin are respectively connected with a power input end, and the GND pin is grounded;

[0048] The I / O pin is connected with the input end of the op-amp follower circuit.

[0049] Optionally, the op-amp follower circuit comprises a voltage division module and the second voltage follower circuit module;

[0050] The input end of the voltage division module is connected with the output end of the analog switch circuit, and the output end is connected with the input end of the second voltage follower circuit module;

[0051] The output end of the second voltage follower circuit module is connected with a corresponding ADC detection end of the MCU control chip;

[0052] The second voltage follower circuit module is used for isolating the analog switch circuit and the MCU control chip.

[0053] Optionally, the voltage division module comprises a first voltage division resistor and a second voltage division resistor, and the second voltage follower circuit module comprises a second voltage follower and a sixth filter capacitor;

[0054] The input end of the first voltage division resistor is connected with the output end of the analog switch circuit, and the output end is respectively connected with the input end of the second voltage division resistor and the input end of the second voltage follower;

[0055] The output end of the second voltage division resistor is grounded;

[0056] The output end of the second voltage follower is connected with a corresponding ADC detection end of the MCU control chip;

[0057] The input end of the sixth filter capacitor is respectively connected with the second voltage follower and a power input end, and the output end is grounded.

[0058] The application realizes time division multiplexing centralized collection of hundreds of photoelectric diode signals by combining a plurality of analog switches with a plurality of voltage following isolation circuits, and only a small amount of ADC interfaces are needed to complete large-scale channel measurement, which not only greatly reduces the hardware cost, power consumption and I / O resource occupation, but also meets the real-time online monitoring demand of high refresh rate, and meanwhile, in cooperation with the capacitance limiting and capacitance resistance filtering circuit, interference is effectively suppressed to ensure the measurement accuracy, and the modular design makes the system structure simple, easy to expand and maintain. BRIEF DESCRIPTION OF DRAWINGS

[0059] The drawings incorporated into the specification and forming a part of the specification, show embodiments consistent with the present application, and together with the specification serve to explain the principles of the present application.

[0060] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows, and obviously, other drawings can be obtained by those skilled in the art without creative labor under the premise of not paying the creative labor.

[0061] One or more embodiments are exemplarily illustrated by the pictures in the drawings corresponding thereto, and these exemplary illustrations do not constitute a limitation on the embodiments, and the elements with the same reference numerals in the drawings represent similar elements, unless otherwise specified, and the drawings do not constitute a proportional limitation.

[0062] Figure 1 A module structure schematic diagram of a multi-channel PD detection device provided for the embodiments of the present application;

[0063] Figure 2 A specific implementation circuit schematic diagram of a multi-channel PD detection circuit provided for the embodiments of the present application. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application, and obviously, the described embodiments are a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0065] The disclosure below provides many different embodiments or examples for implementing various configurations of the present application. For the purpose of simplifying the present application, certain examples of components and arrangements are described herein. These are, of course, merely examples and are in no way limiting of the present application. Furthermore, the present application can be implemented in a variety of different examples and the reference numerals in different examples do not connote any type of relationship between the illustrated embodiments and / or configurations.

[0066] In combination Figure 1 And Figure 2 The names of the electronic components in the circuit of the present application are described. A plurality of PD value input terminals (S0-S15), control signal input terminals (A0-A3), to-be-measured light emitting diodes (PD1-PD304), a first filter capacitor (C1), a current-limiting resistor (R1), a second filter capacitor (C2), a bias voltage (Vr), a sampling resistor (R2), a matching resistor (R3), a third filter capacitor (C3), a first voltage follower (U1A), a fourth filter capacitor (C4), a power input terminal (+5V), a ground GND, an analog switch (U3), a fifth filter capacitor (C5), a first voltage dividing resistor (R4), a second voltage dividing resistor (R5), a second voltage follower (U2A), and a sixth filter capacitor (C6).

[0067] Figure 1 A module structure schematic diagram of a multi-channel PD detection device is provided for the embodiments of the present application. In the embodiments of the present application, the multi-channel PD detection device is suitable for detecting a detection device of a plurality of to-be-measured light emitting diodes. Each to-be-measured light emitting diode (PD1-PD304) corresponds to a PD collection circuit. A plurality of analog switch circuits are included in a multi-channel PD detection device. The analog switch circuit includes a plurality of PD value input terminals (S0-S15). Each PD value input terminal is connected to a corresponding PD collection circuit. That is, one analog switch circuit controls a plurality of PD collection paths, and is connected to a plurality of to-be-measured light emitting diodes, such as Figure 1As shown, one analog switch circuit has 16 PD value input ends, that is, 16 PD collection channels can be controlled, and PD values of 16 to-be-tested light emitting diodes are collected. The multi-channel PD detection device is provided with an MCU control chip for controlling all analog switch circuits. The analog switch circuit further includes a plurality of control signal input ends (A0-A3). The control signal input ends (A0-A3) are connected with signal output ends of the MCU control chip. The output end of each analog switch circuit is connected with an operational amplifier follow-up circuit. That is, each analog switch circuit can make a plurality of PD collection channels pass through an operational amplifier follow-up circuit and finally converge to an ADC detection interface of an analog chip for detection. In the utility model, the to-be-tested light emitting diodes in the plurality of PD collection channels connected with one analog switch circuit can be detected through one ADC detection interface.

[0068] Specifically, the MCU control chip sends control signals to the control signal input ends (A0-A3) of the analog switch circuits through the signal output ends, so as to control the analog switch circuits to turn on the corresponding PD collection circuits, and make the PD collection circuits connected with the operational amplifier follow-up circuit through the analog switch circuit. The output end of the operational amplifier follow-up circuit is connected with the ADC detection end of the MCU control chip.

[0069] For example, there are 19 analog switch circuits. The MCU control chip sends the same control instruction (when A0=0, A1=0, A2=0, A3=0) to the analog switch circuit 1 to the analog switch circuit 19 through the signal output end, so as to turn on the PD collection circuit connected with S0. Then, the 19 analog switch circuits turn on the PD collection circuit connected with S0. At this time, the 19 operational amplifier follow-up circuits connected with the 19 analog switch circuits are connected with the 19 ADC detection interfaces of the MCU control chip, and the 19 operational amplifier follow-up circuits also detect the to-be-tested light emitting diodes on the 19 S0 channels, respectively.

[0070] For example, there are 19 analog switch circuits. The MCU control chip sends the same control instruction (when A0=0, A1=0, A2=0, A3=0) to the analog switch circuit 1 to the analog switch circuit 19 through the signal output end, so as to turn on the PD collection circuit connected with S0. Then, the 19 analog switch circuits turn on the PD collection circuit connected with S0. At this time, the 19 operational amplifier follow-up circuits connected with the 19 analog switch circuits are connected with the 19 ADC detection interfaces of the MCU control chip, and the 19 operational amplifier follow-up circuits also detect the to-be-tested light emitting diodes on the 19 S0 channels, respectively.

[0071] The MCU control chip issues the next round of control commands (when A0 = 0, A1 = 0, A2 = 0, and A3 = 1) to analog switch circuits 1 through 19 via the signal output terminal. This turns on the PD acquisition circuit connected to S1. All 19 analog switch circuits then turn on the PD acquisition circuit connected to channel S1. At this point, the 19 op amp follower circuits connected to these 19 analog switch circuits are connected to the 19 ADC detection interfaces of the MCU control chip, and each of these 19 LEDs under test on channel S1 measures the data. Each round of control commands samples data from 19 LEDs under test. This continues in binary format until 16 rounds have been issued, with A0 = 1, A1 = 1, A2 = 1, and A3 = 1. Once all PD acquisition circuits connected to channels S0 through S15 are turned on, the ADCs detect a total of 16 × 19 = 304 LEDs under test. In actual application, after all the light-emitting diodes to be tested are tested, the cyclic test can be started. The signal output end of the MCU control chip will send a control instruction again. When A0=0, A1=0, A2=0, and A3=0, the PD acquisition circuit connected to the S0 channel will be turned on again, and then turned on to the S15 channel and the cycle will repeat.

[0072] In the prior art, each light-emitting diode to be tested must correspond to an ADC detection interface. If 304 light-emitting diodes to be tested are to be tested, 304 ADC detection interfaces are required. However, in this application, by combining an analog switch circuit with an op amp follower circuit, only 19 ADC detection interfaces are required. After multiplexing through the analog switch, multiple PD signals are sequentially sent to the op amp follower circuit, and finally efficient collection is achieved through a small number of ADC interfaces. It has the characteristics of a large number of PD collection channels and a small number of ADC interfaces, and is suitable for centralized collection of large-scale PD channels.

[0073] like Figure 2 As shown, Figure 2The specific implementation circuit schematic of a multi-path PD detection circuit provided by the embodiment of the application is shown. Each PD acquisition circuit comprises a capacity limiting module, a PD input module, a resistance-capacitance module and a first voltage follower circuit module. In the present application, the path corresponding to PD1 is taken as an example for description, and the principles of other to-be-detected photodiodes are equivalent. The capacity limiting module comprises a first filter capacitor (C1), a current limiting resistor (R1) and a second filter capacitor (C2). The input end of the first filter capacitor (C1) is connected to the output end of a bias voltage (Vr), and the output end is connected to the ground GND. The input end of the current limiting resistor (R1) is connected to the output end of the bias voltage (Vr), and the output end is connected to the input end of the second filter capacitor (C2) and the input end of the PD input module. The first filter capacitor (C1) and the second filter capacitor (C2) are used to suppress interference and improve circuit stability. The current limiting resistor (R1) is used to limit the current of the protection circuit. The bias voltage (Vr) is used to provide a reverse bias for the PD1, so that the photoelectric current output by the PD1 is more stable, and the responsivity is increased.

[0074] The PD input module comprises a to-be-detected photodiode (PD1) and a sampling resistor (R2). After the optical signal passes through the to-be-detected photodiode, it is converted into a voltage signal after flowing through the sampling resistor. A PN junction with a photosensitive feature is usually used in a die, so the to-be-detected photodiode (PD1) comprises a P pole (anode) and an N pole (cathode). The cathode of the to-be-detected photodiode (PD1) is connected to the output end of the capacity limiting module, and the anode of the to-be-detected photodiode (PD1) is connected to the input end of the sampling resistor (R2) and the input end of the resistance-capacitance module. The output end of the sampling resistor (R2) is connected to the ground GND. The to-be-detected photodiode (PD1) is used to convert the optical signal into a photoelectric current. The sampling resistor (R2) is used to obtain a voltage signal according to the photoelectric current.

[0075] The resistance-capacitance module comprises a matching resistor (R3) and a third filter capacitor (C3). The input end of the matching resistor (R3) is connected to the output end of the PD input module, and the output end is connected to the input end of the third filter capacitor (C3) and the input end of the first voltage follower circuit module. The matching resistor (R3) is used for impedance matching to prevent signal reflection and improve signal transmission quality. The third filter capacitor (C3) is used to suppress interference and improve circuit stability.

[0076] The first voltage follower (U1A) is connected with the output end of the resistance-capacitance module and the input end of the analog switch circuit; the input end of the fourth filter capacitor (C4) is connected with the first voltage follower and the power input end (+5V) respectively, and the output end is grounded GND. The first voltage follower adopts LM324, which is essentially an operational amplifier circuit, and is used for isolating the PD input module from the analog switch circuit to prevent the signal source from being affected by the subsequent load; the fourth filter capacitor (C4) is used for suppressing interference and improving circuit stability.

[0077] As shown in Figure 2 The analog switch circuit includes an analog switch (U3) and a fifth filter capacitor (C5), and the analog switch adopts a single-chip microcomputer control chip CD4067BM. The input end of the fifth filter capacitor C5 is connected with the power input end (+5V) and the analog switch (U3) respectively, and the output end is grounded GND. The analog switch (U3) is used for closing the corresponding PD acquisition circuit in response to the control signal, so that one ADC can detect multiple to-be-detected light-emitting diodes PD through one analog switch to control multiple PD acquisition paths; the fifth filter capacitor (C5) is used for suppressing interference and improving circuit stability.

[0078] Specifically, the analog switch includes a plurality of PD value input pins (S0-S15), a plurality of control signal input pins (A0-A3), an I / O pin, a VDD pin, an EN pin and a GND pin. Each PD value input pin is connected with the output end of the corresponding PD acquisition circuit; each control signal input pin is connected with the signal output pin of the MCU control chip; the input end of the fifth filter capacitor (C5) is connected with the VDD pin and the EN pin respectively, and the output end is grounded; the VDD pin and the EN pin are connected with the power input end (+5V) respectively, and the GND pin is grounded; the I / O pin is connected with the input end of the operational amplifier follower circuit.

[0079] The control signal input pin (A0-A3) is used for connecting the MCU control chip, and the MCU control chip sends a control signal to the analog switch (U3) through the control signal input pin (A0-A3). The PD value input pin (S0-S15) is used for connecting with a plurality of PD acquisition circuits, and the analog switch (U3) turns on the corresponding PD acquisition circuit through each PD value input pin and the line. The VDD pin is used for providing the voltage required by the chip. The EN pin is used for enabling the control chip to work or not, and the high level or low level enables, that is, the high level or low level is effective, depending on the chip specification. The GND pin is used for forming a current loop with the VDD to form a power supply path. The I / O pin is used for input / output multiplexing pin, which is connected with the input end of the operational amplifier follower circuit.

[0080] As shown in Figure 2As shown, the operational amplifier follower circuit includes a voltage division module and the second voltage follower circuit module. The voltage division module includes a first voltage division resistor (R4) and a second voltage division resistor (R5), the input end of the first voltage division resistor (R4) is connected with the output end of the analog switch circuit, the output end is connected with the input end of the second voltage division resistor (R5) and the input end of the second voltage follower (U2A) respectively; and the output end of the second voltage division resistor (R5) is grounded. The first voltage division resistor (R4) and the second voltage division resistor (R5) are used for voltage division in the circuit, and play a role in protecting the circuit.

[0081] The second voltage follower circuit module includes a second voltage follower (U2A) and a sixth filter capacitor (C6). The output end of the second voltage follower (U2A) is connected with the ADC detection end (ADC interface) of the corresponding MCU control chip; the input end of the sixth filter capacitor (C6) is connected with the second voltage follower (U2A) and the power input end (+5V) respectively, and the output end is grounded. The second voltage follower adopts LM324, which is used for isolating the analog switch circuit and the ADC detection end of the MCU control chip; and the sixth filter capacitor (C6) is used for suppressing interference and improving the stability of the circuit.

[0082] The utility model has the following beneficial effects:

[0083] (1) Large-scale channel centralized collection: time division multiplexing is carried out on hundreds of PD signals through a plurality of analog switches, and the centralized collection of more than 300 photodiodes is realized, and there is no need to equip each PD with an independent ADC channel.

[0084] (2) The number of ADC interfaces is significantly reduced: a small number of ADC ports (such as 19) can complete large-scale data acquisition, greatly reduce the I / O resource occupation of the single-chip microcomputer, and break the ADC channel bottleneck of the traditional scheme.

[0085] (3) Cost and power consumption are reduced: the number of ADC chips and external filter, voltage follower and other components is reduced, the PCB area is reduced, and the material cost and system power consumption are reduced.

[0086] (4) Real-time and response speed are excellent: the MCU switches the analog switch channel in sequence and quickly, which can meet the high refresh rate requirement of the real-time online monitoring of hundreds of PDs in the COS aging system.

[0087] (5) Anti-interference performance is improved: the limit capacity, resistance-capacitance filter and multi-stage voltage follower isolation circuit jointly suppress interference harmonics, and ensure the stability and measurement accuracy of the collected signals.

[0088] (6) Simple structure and easy expansion: modular design, consistent channel circuit and can be added, which is convenient for subsequent channel expansion and system upgrade and maintenance.

[0089] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above-mentioned division of each functional unit and module is exemplified, and in actual application, the above-mentioned functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or software.

[0090] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in detail in a certain embodiment can be referred to the related description of other embodiments.

[0091] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the present application can be realized in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0092] In the embodiments provided in the present application, it should be understood that the disclosed circuit can be implemented in other ways. For example, the above-described circuit is only schematic, for example, the division of the module or unit is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units or components shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0093] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or software.

[0094] The integrated module / unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by a computer program instructing related hardware, and the computer program can be stored in a computer readable storage medium. The computer program can implement the steps of each method embodiment described above when executed by a processor. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or some intermediate forms. The computer readable medium can include any entity or device, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. that can carry the computer program code. It should be noted that the contents included in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals.

[0095] The above-mentioned embodiment methods can also be completed by a computer program product, which, when running on a terminal device, causes the terminal device to execute the steps in the above-mentioned various method embodiments.

[0096] The above-mentioned embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalent replacements; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A multi-channel PD detection device, characterized in that: The multi-channel PD detection device includes multiple PD detection circuits and an MCU control chip, the MCU control chip includes multiple signal output terminals and multiple ADC detection terminals, and each of the PD detection circuits includes multiple PD acquisition circuits, analog switch circuits, and op amp follower circuits; The input end of the analog switch circuit includes a plurality of PD value input ends and a plurality of control signal input ends; The output end of each PD acquisition circuit is correspondingly connected to each PD value input end of the analog switch circuit; The signal output terminals of the MCU control chips are connected to the control signal input terminals of the analog switch circuits accordingly; The output end of the analog switch circuit is connected to the input end of the operational amplifier follower circuit; The output end of the operational amplifier follower circuit is connected to the ADC detection end of the corresponding MCU control chip; The PD acquisition circuit is used to acquire the PD value of the photodiode to be tested, and the PD value is the efficiency of the photodiode to be tested in converting the optical signal into the electrical signal; The analog switch circuit is used to connect the corresponding PD acquisition path and the corresponding ADC detection terminal of the MCU control chip in response to the control signal of the MCU control chip; The operational amplifier follower circuit is used to isolate the analog switch circuit from the MCU control chip.

2. The multi-channel PD detection device according to claim 1, characterized in that: Each of the PD acquisition circuits includes a capacitance limiting module, a PD input module, a resistance-capacitance module, and a first voltage follower circuit module; Therefore, the input end of the capacitance limiting module is connected to the output end of the bias voltage, and the output end is connected to the input end of the PD input module; The output end of the PD input module is connected to the input end of the resistance-capacitance module; The output end of the resistance-capacitance module is connected to the input end of the first voltage follower circuit module; The output end of the first voltage follower circuit module is connected to the analog switch circuit; The PD input module is used to convert the optical signal of the photodiode to be tested into an electrical signal and output a voltage value; The capacity limiting module is used to limit the current passing through; The bias voltage is used to provide a reverse bias voltage to the photodiode to be tested; The resistance-capacitance module is used to suppress interference harmonics; The first voltage follower circuit module is used to isolate the PD input module from the analog switch circuit.

3. The multi-channel PD detection device according to claim 2, characterized in that: The capacitance limiting module includes a first filter capacitor, a current limiting resistor and a second filter capacitor; The input end of the first filter capacitor is connected to the output end of the bias voltage, and the output end is grounded; The input end of the current limiting resistor is connected to the output end of the bias voltage, and the output end is connected to the input end of the second filter capacitor and the input end of the PD input module respectively; An output terminal of the second filter capacitor is grounded.

4. The multi-channel PD detection device according to claim 2, characterized in that: The PD input module includes a photodiode to be measured and a sampling resistor; The cathode of the photodiode to be tested is connected to the output end of the capacitance limiting module; The anode of the photodiode to be tested is connected to the input end of the sampling resistor R2 and the input end of the resistance-capacitance module respectively; The output end of the sampling resistor is grounded; The photodiode to be tested is used to convert the optical signal into a photocurrent; The sampling resistor is used to obtain a voltage signal according to the photocurrent.

5. The multi-channel PD detection device according to claim 2, characterized in that: The resistance-capacitance module includes a matching resistor and a third filter capacitor; The input end of the matching resistor is connected to the output end of the PD input module, and the output end is connected to the input end of the third filter capacitor and the input end of the first voltage follower circuit module respectively; An output terminal of the third filter capacitor is grounded.

6. The multi-channel PD detection device according to claim 2, characterized in that: The first voltage follower circuit module includes a first voltage follower and a fourth filter capacitor; The input end of the first voltage follower is connected to the output end of the resistance-capacitance module, and the output end is connected to the analog switch circuit; The input end of the fourth filter capacitor is connected to the first voltage follower and the power input end respectively, and the output end is grounded.

7. The multi-channel PD detection device according to claim 1, characterized in that: The analog switch circuit includes an analog switch and a fifth filter capacitor, and the analog switch adopts a single-chip microcomputer control chip; The input end of the fifth filter capacitor is connected to the power input end and the analog switch respectively, and the output end is grounded.

8. The multi-channel PD detection device according to claim 7, characterized in that: The analog switch includes a plurality of PD value input pins, a plurality of control signal input pins, an I / O pin, a VDD pin, an EN pin and a GND pin; Each of the PD value input pins is connected to the output end of each corresponding PD acquisition circuit; Each of the control signal input pins is connected to the signal output pin of the MCU control chip; The input end of the fifth filter capacitor is connected to the VDD pin and the EN pin respectively, and the output end is grounded; The VDD pin and the EN pin are respectively connected to the power input terminal, and the GND pin is grounded; The I / O pin is connected to the input end of the operational amplifier follower circuit.

9. The multi-channel PD detection device according to claim 1, characterized in that: The operational amplifier follower circuit includes a voltage divider module and a second voltage follower circuit module; The input end of the voltage divider module is connected to the output end of the analog switch circuit, and the output end is connected to the input end of the second voltage follower circuit module; The output end of the second voltage follower circuit module is connected to the ADC detection end of the corresponding MCU control chip; The second voltage follower circuit module is used to isolate the analog switch circuit and the MCU control chip.

10. The multi-channel PD detection device according to claim 9, characterized in that: The voltage dividing module includes a first voltage dividing resistor and a second voltage dividing resistor, and the second voltage follower circuit module includes a second voltage follower and a sixth filter capacitor; The input end of the first voltage-dividing resistor is connected to the output end of the analog switch circuit, and the output end is connected to the input end of the second voltage-dividing resistor and the input end of the second voltage follower respectively; The output end of the second voltage-dividing resistor is grounded; The output end of the second voltage follower is connected to the ADC detection end of the corresponding MCU control chip; The input end of the sixth filter capacitor is connected to the second voltage follower and the power input end respectively, and the output end is grounded.

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