Signal acquisition circuit and control method of signal acquisition circuit

Abstract

The invention discloses a signal acquisition circuit and a control method of the signal acquisition circuit, and relates to the technical field of signal acquisition. The signal acquisition circuit comprises a photoelectric detector, a first amplification module and at least one leakage current sampling module, wherein the leakage current sampling module is arranged on an electric signal transmission path where the photoelectric detector and the first amplification module are located; any leakage current sampling module is used for sampling a target electric signal in an electric signal transmission path connected with a first end of the leakage current sampling module when a voltage in a corresponding target power supply voltage range is used for supplying power to a photoelectric detection device in at least part of time periods in a leakage current sampling stage, a leakage current sampling electric signal is obtained; and in the working stage, when the target power supply voltage is adopted to supply power to the photoelectric detector, electric signal compensation is carried out based on the leakage current sampling electric signal. According to the embodiment of the invention, leakage current compensation of the photoelectric detector can be effectively realized.

Description

Technical Field

[0001] This application belongs to the field of signal acquisition technology, and in particular relates to a signal acquisition circuit and a control method for the signal acquisition circuit. Background Technology

[0002] Currently, weak light signal detection plays a crucial role in various fields. For example, in the field of image sensors, weak light signal detection technology is used to achieve high-quality image capture. In the field of optical sensors, it is used for ambient light intensity measurement and spectral analysis. In industrial automated production lines, it can be used to detect information such as the position, size, and even appearance defects of objects. Currently, these weak light signal detection technologies are typically implemented using photoelectric signal acquisition circuits. These circuits include photodetectors and operational amplifiers, enabling the conversion of optical signals into electrical signals.

[0003] However, in photoelectric signal acquisition circuits, for example, a photomultiplier tube (PMT) is a photoelectric detection device. Due to the inherent physical characteristics of the PMT, it is prone to leakage current during operation. This leakage current acts as noise and is superimposed on the photocurrent generated by the optical signal, thus affecting the sensitivity and accuracy of the detection. This negatively impacts the overall noise and signal-to-noise ratio of the acquisition circuit, hindering the improvement of the signal acquisition dynamic range and linearity. Summary of the Invention

[0004] This application provides a signal acquisition circuit and a control method for the signal acquisition circuit, which can effectively compensate for the leakage current of the photodetector device, thereby improving the signal acquisition accuracy of the overall acquisition circuit and enhancing the dynamic range and linearity of the signal acquisition.

[0005] In a first aspect, embodiments of this application provide a signal acquisition circuit, which includes:

[0006] A photoelectric detection device is used to detect optical signals under the power supply voltage provided at the power supply terminal and output the detection current corresponding to the optical signal;

[0007] The first amplification module has its first input terminal electrically connected to the output terminal of the photodetector. The first amplification module is used to amplify the electrical signal received at its first input terminal and then output it.

[0008] At least one leakage current sampling module, the first and second ends of the leakage current sampling module are set on the electrical signal transmission path where the photodetector and the first amplification module are located, and the third end of the leakage current sampling module is electrically connected to the ground terminal.

[0009] Any leakage current sampling module is used to: during at least a portion of the leakage current sampling period, when powering the photodetector with a voltage within the corresponding target power supply voltage range, sample the target electrical signal in the electrical signal transmission path connected to the first terminal of the leakage current sampling module to obtain a leakage current sampling electrical signal.

[0010] During the working phase, when the target supply voltage is used to supply power to the photodetector, the electrical signal in the electrical signal transmission path connected to the second terminal of the leakage current sampling module is compensated based on the leakage current sampling electrical signal. The target supply voltage range is different for different leakage current sampling modules, and the target supply voltage corresponds to the target supply voltage range.

[0011] In some possible implementations, at least one leakage current sampling module includes a first leakage current sampling module; a first terminal of the first leakage current sampling module is electrically connected to the output terminal of the photodetector, and a second terminal of the first leakage current sampling module is electrically connected to the second input terminal of the first amplification module.

[0012] Any first leakage current sampling module is used to: during at least a portion of the leakage current sampling period, when powering the photodetector with a voltage within the corresponding target power supply voltage range, sample the first target electrical signal output by the photodetector to obtain a leakage current sampling electrical signal.

[0013] And / or, the signal acquisition circuit further includes a second amplification module, and at least one leakage current sampling module includes a second leakage current sampling module; the first input terminal of the second amplification module is electrically connected to the output terminal of the first amplification module, the first terminal of the second leakage current sampling module is electrically connected to the output terminal of the first amplification module, and the second terminal of the second leakage current sampling module is electrically connected to the second input terminal of the second amplification module.

[0014] The second amplification module is used to amplify the electrical signal difference between its first input terminal and its second input terminal, and output the amplified electrical signal.

[0015] Any second leakage current sampling module is used to: sample the second target electrical signal output by the first amplification module to obtain a leakage current sampling electrical signal during at least a portion of the leakage current sampling period, while supplying power to the photodetector device with a voltage within the corresponding target power supply voltage range.

[0016] In some possible implementations, the leakage current sampling module includes:

[0017] The first switching unit, the first end of the first switching unit is the first end of the leakage current sampling module;

[0018] The sampling unit has a first terminal electrically connected to the second terminal of the first switching unit, and the second terminal of the sampling unit is electrically connected to the ground terminal.

[0019] The second switching unit has its first end electrically connected to the first end of the sampling unit, and its second end is the second end of the leakage current sampling module.

[0020] During at least a portion of the leakage current sampling phase, when the photodetector is powered by a voltage within the corresponding target supply voltage range, the first switching unit is turned on and the second switching unit is turned off. The sampling unit is used to sample the target electrical signal transmitted by the first switching unit to obtain the leakage current sampling electrical signal.

[0021] During the working phase, the first switching unit is turned off, the second switching unit is turned on, and the sampling unit is used to compensate for the leakage current in the detection current of the photodetector based on the leakage current sampling electrical signal.

[0022] In some possible implementations, at least one leakage current sampling module includes a second leakage current sampling module, the second leakage current sampling module further including:

[0023] The first isolation unit has its first input terminal electrically connected to its output terminal, and its second input terminal electrically connected to the second terminal of the first switching unit and the first terminal of the leakage current sampling module, respectively.

[0024] The signal acquisition circuit also includes:

[0025] The second isolation unit has its first input terminal electrically connected to its output terminal, and its second input terminal electrically connected to the output terminal of the first amplification module.

[0026] In some possible implementations, the second leakage current sampling module further includes:

[0027] The third switching unit has its first terminal electrically connected to the first input terminal of the first isolation unit, and its second terminal electrically connected to the output terminal of the first isolation unit.

[0028] During the working phase, the third switch unit is turned on, connecting the first input terminal of the first isolation unit with the output terminal of the first isolation unit.

[0029] In some possible implementations, the signal acquisition circuit may also include a third amplification module;

[0030] In the case that the signal acquisition circuit does not include the second amplification module, the input terminal of the third amplification module is electrically connected to the output terminal of the first amplification module, and the output terminal of the third amplification module is electrically connected to the acquisition signal output terminal.

[0031] Alternatively, if the signal acquisition circuit includes a second amplification module, the input terminal of the third amplification module is electrically connected to the output terminal of the second amplification module, and the output terminal of the third amplification module is electrically connected to the acquired signal output terminal.

[0032] The third amplification module is used to amplify the voltage signal received at its input terminal and then output it.

[0033] In some possible implementations, the number of leakage current sampling modules in at least one leakage current sampling module is n, where n is a positive integer;

[0034] During the leakage current sampling stage, n leakage current sampling modules are used to sample the target electrical signal of the photodetector device under n power supply voltage ranges in a time-division manner, so as to obtain n leakage current sampling electrical signals corresponding to the n power supply voltage ranges. The n power supply voltage ranges correspond one-to-one with the n leakage current sampling modules, and the n power supply voltage ranges include the target power supply voltage range.

[0035] During the working phase, when the photodetector is powered by the target supply voltage, the leakage current in the detection current of the photodetector is compensated based on the leakage current sampling signal in the leakage current sampling module corresponding to the target supply voltage range.

[0036] In some possible implementations, the number of leakage current sampling modules in at least one leakage current sampling module is n, where n is a positive integer;

[0037] During the leakage current sampling stage, the first switching unit in the n leakage current sampling modules is turned on in a time-division manner, and the second switching unit in the n leakage current sampling modules is turned off. The sampling units in the n leakage current sampling modules are used to sample the target electrical signal of the photodetector device under the n power supply voltage range in a time-division manner, so as to obtain n leakage current sampling electrical signals corresponding to the n power supply voltage ranges. The n power supply voltage ranges correspond one-to-one with the n leakage current sampling modules, and the n power supply voltage ranges include the target power supply voltage range.

[0038] During the working phase, when the photodetector is powered by the target supply voltage, the first switch unit in the leakage current sampling module corresponding to the target supply voltage range is turned off and the second switch unit is turned on. The sampling unit is used to compensate for the leakage current in the detection current of the photodetector based on the corresponding leakage current sampling electrical signal.

[0039] In some possible implementations, the signal acquisition circuit further includes:

[0040] The current regulation module has its control terminal electrically connected to the drive voltage terminal, its first terminal electrically connected to the reference voltage terminal, and its second terminal electrically connected to the output terminal of the photodetector.

[0041] The current regulation module is used to regulate the current signal received at the first input terminal of the first amplification module under the control of the adjustable voltage provided at the drive voltage terminal and / or the reference voltage terminal.

[0042] In some possible implementations, the current regulation module includes transistors;

[0043] The gate of the transistor is electrically connected to the driving voltage terminal, the source of the transistor is electrically connected to the reference voltage terminal, and the drain of the transistor is electrically connected to the output terminal of the photodetector.

[0044] In some possible implementations, the signal acquisition circuit further includes a switch control module, which includes at least one comparator and a target encoder;

[0045] At least one comparator’s first input terminal is electrically connected to the target node, and at least one comparator’s second input terminal is electrically connected to at least one reference voltage terminal. The target node is a node between two resistors connected in series between the power supply terminal and the ground terminal. At least one reference voltage terminal provides a different reference voltage.

[0046] The output of at least one comparator is electrically connected to at least one input pin of the target encoder, or at least some of the comparators are electrically connected to the input pins of the target encoder via inverters.

[0047] At least one output pin of the target encoder is electrically connected to the control terminal of the first or second switching unit in at least one leakage current sampling module. The target encoder is used to provide a corresponding turn-on signal or turn-off signal to the control terminal of the first or second switching unit in at least one leakage current sampling module according to the level signal received by at least one input pin.

[0048] In some possible implementations, the first amplification module includes a transimpedance amplifier;

[0049] The second amplification module includes a differential amplifier circuit or a fully differential amplifier circuit.

[0050] Based on the same inventive concept, in a second aspect, embodiments of this application provide a control method for a signal acquisition circuit, applied to a signal acquisition circuit as described in any embodiment of the first aspect of this application. The control method for the signal acquisition circuit includes:

[0051] During at least a portion of the leakage current sampling phase, when power is supplied to the photodetector using a voltage within the target supply voltage range, the leakage current sampling module corresponding to the target supply voltage range is controlled to sample the target electrical signal in the electrical signal transmission path connected to the first terminal of the leakage current sampling module to obtain the leakage current sampling electrical signal.

[0052] During the working phase, when the target supply voltage is used to supply power to the photodetector, the leakage current sampling module corresponding to the target supply voltage range is controlled to compensate for the leakage current in the detection current of the photodetector based on the leakage current sampling signal. The target supply voltage range is different for different leakage current sampling modules, and the target supply voltage corresponds to the target supply voltage range.

[0053] Thirdly, embodiments of this application provide a control device for a signal acquisition circuit, the control device for the signal acquisition circuit comprising:

[0054] Processor and memory storing computer program instructions;

[0055] When the processor executes the computer program instructions, it implements the control method for the signal acquisition circuit provided in any of the above embodiments of this application.

[0056] Fourthly, embodiments of this application provide a computer storage medium storing computer program instructions, which, when executed by a processor, implement the control method of the signal acquisition circuit provided in any of the above embodiments of this application.

[0057] Fifthly, embodiments of this application provide a computer program product in which instructions, when executed by a processor of an electronic device, cause the electronic device to perform a control method for a signal acquisition circuit as provided in any of the embodiments of this application described above.

[0058] This application provides a signal acquisition circuit and a control method for the signal acquisition circuit. At least one leakage current sampling module is set on the electrical signal transmission path where the photodetector and the first amplification module are located, and a correspondence is established between different target supply voltage ranges and different leakage current sampling modules. Thus, during at least a portion of the leakage current sampling phase, the power supply terminal supplies power to the photodetector using a voltage within the corresponding target supply voltage range. In this case, the leakage current sampling module corresponding to the target supply voltage range samples the target electrical signal in the electrical signal transmission path connected to its first terminal. After sampling the aforementioned target electrical signal related to leakage current, a leakage current sampling signal is obtained. This leakage current sampling signal is stored in the leakage current sampling module and can be used for subsequent leakage current compensation.

[0059] Next, during the operation of the photodetector, the leakage current sampling module corresponding to the target supply voltage range corresponding to the current target supply voltage of the photodetector is determined. The corresponding leakage current sampling module transmits its pre-stored leakage current sampling signal to the signal transmission path connected to its second terminal, effectively adjusting the final output signal of the signal acquisition circuit based on the current supply voltage. Therefore, the signal acquisition circuit and its control method provided in this application can effectively compensate for the leakage current of the photodetector under different supply voltages based on at least one leakage current sampling module, thereby improving the overall signal acquisition accuracy of the acquisition circuit and enhancing the dynamic range and linearity of the signal acquisition. Attached Figure Description

[0060] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0061] Figure 1 This is a schematic diagram of the relationship between the power supply voltage and leakage current of a photomultiplier tube provided in an embodiment of this application;

[0062] Figure 2 This is a schematic diagram of the structure of a signal acquisition circuit in a related art provided in an embodiment of this application;

[0063] Figure 3 This is a schematic diagram of the structure of a signal acquisition circuit provided in an embodiment of this application;

[0064] Figure 4 This is a schematic diagram of the signal acquisition circuit provided in another embodiment of this application;

[0065] Figure 5 This is a schematic diagram of the signal acquisition circuit provided in another embodiment of this application;

[0066] Figure 6 This is a schematic diagram of the signal acquisition circuit provided in another embodiment of this application;

[0067] Figure 7 This is a schematic diagram of the signal acquisition circuit provided in another embodiment of this application;

[0068] Figure 8 This is a schematic diagram of the signal acquisition circuit provided in another embodiment of this application;

[0069] Figure 9 This is a schematic diagram of the signal acquisition circuit provided in another embodiment of this application;

[0070] Figure 10 This is a schematic diagram of the signal acquisition circuit provided in another embodiment of this application;

[0071] Figure 11 This is a schematic diagram of the signal acquisition circuit provided in another embodiment of this application;

[0072] Figure 12 This is a timing diagram of a leakage current sampling module provided in an embodiment of this application;

[0073] Figure 13 This is a timing diagram of a leakage current sampling module provided in another embodiment of this application;

[0074] Figure 14 This is a timing diagram of a leakage current sampling module provided in another embodiment of this application;

[0075] Figure 15 This is a schematic diagram of the signal acquisition circuit provided in another embodiment of this application;

[0076] Figure 16 This is a schematic diagram of the signal acquisition circuit provided in another embodiment of this application;

[0077] Figure 17 This is a schematic diagram of the signal acquisition circuit provided in another embodiment of this application;

[0078] Figure 18 This is a schematic flowchart of a control method for a signal acquisition circuit provided in an embodiment of this application;

[0079] Figure 19 This is a schematic diagram of the structure of a control device for a signal acquisition circuit provided in an embodiment of this application.

[0080] In the attached image:

[0081] 10. Photodetector; 20. First amplification module; 30. Leakage current sampling module; 31. First leakage current sampling module; 32. Second leakage current sampling module; 101 / SW1_1~SW1_n, First switching unit; 102 / SW2_1~SW2_n, Second switching unit; 103 / C1~Cn, Sampling unit; 104 / A1~An, First isolation unit; 105 / A0, Second isolation unit; 106 / SW3_1~SW3_n, First... Three-switch unit; 40, second amplification module; 50, third amplification module; 60, current regulation module; 70, switch control module; Q1, transistor; Vcon, drive voltage terminal; Vref, reference voltage terminal; Vpmt, power supply terminal; GND, ground terminal; Vcmp1~Vcmpn, reference voltage terminal; CMP1~CMPn, comparator; INV1~INVn, inverter; ENC, encoder; N, target node; 100, signal acquisition circuit. Detailed Implementation

[0082] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0083] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0084] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0085] It should be noted that the transistors in the embodiments of this application can be either N-type or P-type transistors. For N-type transistors, the on-state level is high and the off-state level is low. That is, when the gate of an N-type transistor is high, its first and second terminals are connected; when the gate of an N-type transistor is low, its first and second terminals are off. For P-type transistors, the on-state level is low and the off-state level is high. That is, when the control terminal of a P-type transistor is low, its first and second terminals are connected; when the control terminal of a P-type transistor is high, its first and second terminals are off. In specific implementations, the gate of each transistor is used as its control terminal. Furthermore, depending on the signal and type of the gate of each transistor, its first terminal can be used as the source and its second terminal as the drain, or vice versa. No distinction is made here. Additionally, the on-state and off-state levels in the embodiments of this invention are general terms. The on-state level refers to any level that enables the transistor to conduct, and the off-state level refers to any level that enables the transistor to turn off / become off.

[0086] In the embodiments of this application, the term "electrical connection" can refer to a direct electrical connection between two components, or it can refer to an electrical connection between two components via one or more other components.

[0087] Various modifications and variations can be made to this application without departing from its spirit or scope, which will be apparent to those skilled in the art. Therefore, this application is intended to cover modifications and variations falling within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the embodiments provided in this application can be combined with each other without contradiction.

[0088] Before describing the technical solutions provided in the embodiments of this application, in order to facilitate understanding of the embodiments of this application, this application first specifically explains the problems existing in the related technologies:

[0089] As mentioned earlier, in photoelectric signal acquisition circuits, photoelectric detection devices such as photomultiplier tubes are prone to leakage current during operation. Specifically, taking a photomultiplier tube as an example, a photomultiplier tube currently mainly consists of two parts: a cathode chamber and a secondary emission multiplication system composed of several electrodes. In practical applications, a DC voltage needs to be applied sequentially to each electrode and the anode to provide a current source for secondary electron multiplication.

[0090] However, in practical applications, due to factors such as dark current within the photomultiplier tube and defects in its electrode material, the photomultiplier tube will still output a certain leakage current even when there is no light illumination. The presence of leakage current affects the detection current output by the photomultiplier tube during light detection. The mixing of the leakage current signal and the photocurrent signal leads to deviations in the measurement results during actual light signal measurement, limiting the detection capability of the photoelectric signal acquisition circuit under different light signal input intensities, thus affecting signal acquisition accuracy and making it difficult to improve the dynamic range of the circuit's signal acquisition.

[0091] Please see below. Figure 1 , Figure 1 This is a schematic diagram showing the relationship between the supply voltage and leakage current of a photomultiplier tube provided in one embodiment of this application. Figure 1 As shown, the inventors of this application further discovered that the leakage current of the photomultiplier tube varies under different supply voltage conditions, which exacerbates the adverse effects of leakage current on the dynamic range and linearity of the photomultiplier tube. Therefore, this dynamically changing leakage current of the photomultiplier tube also poses a challenge to leakage current correction in practical signal acquisition circuits.

[0092] also, Figure 2 This is a schematic diagram of the signal acquisition circuit in a related technology provided in an embodiment of this application. For example... Figure 2 As shown, in current photoelectric signal acquisition circuits, taking a photomultiplier tube (PMT) as an example, the current signal output by the PMT is typically acquired and amplified using a subsequent operational amplifier (op-amp) 20. This op-amp 20 is usually a transimpedance amplifier (TIA), which includes amplifier OP1 and feedback resistor Rf. The inventors of this application have also discovered that the noise of the op-amp TIA itself can affect the overall noise and signal-to-noise ratio of the acquisition circuit.

[0093] Therefore, the industry still urgently needs a new type of signal acquisition circuit to effectively correct the leakage current of photodetectors, thereby improving the signal acquisition accuracy of the overall acquisition circuit and enhancing the dynamic range and linearity of signal acquisition.

[0094] To address the problems of the prior art, embodiments of this application provide a signal acquisition circuit and a control method for the signal acquisition circuit. It should be noted that the embodiments provided in this application are not intended to limit the scope of this application.

[0095] The signal acquisition circuit provided in the embodiments of this application will be described below. Please refer to... Figure 3 , Figure 3This is a schematic diagram of the signal acquisition circuit provided in one embodiment of this application. Figure 3 As shown, the signal acquisition circuit 100 includes:

[0096] The photodetector 10 is used to detect optical signals under the power supply voltage provided by the power supply terminal Vpmt and output the detection current corresponding to the optical signal.

[0097] The first amplification module 20 has its first input terminal electrically connected to the output terminal of the photodetector device 10. The first amplification module 20 is used to amplify the electrical signal received at its first input terminal and then output it.

[0098] At least one leakage current sampling module 30, the first and second ends of the leakage current sampling module 30 are disposed on the electrical signal transmission path between the photodetector and the first amplification module 20, and the third end of the leakage current sampling module 30 is electrically connected to the ground terminal GND.

[0099] Any leakage current sampling module 30 is used to: during at least a portion of the leakage current sampling period, when powering the photodetector device 10 with a voltage within the corresponding target power supply voltage range, sample the target electrical signal in the electrical signal transmission path connected to the first terminal of the leakage current sampling module 30 to obtain a leakage current sampling electrical signal.

[0100] During the working phase, when the photodetector 10 is powered by the target supply voltage, the electrical signal in the electrical signal transmission path connected to the second terminal of the leakage current sampling module 30 is compensated based on the leakage current sampling electrical signal, and the leakage current in the detection current of the photodetector is compensated. The target supply voltage range is different for different leakage current sampling modules 30, and the target supply voltage corresponds to the target supply voltage range.

[0101] In this application, the photodetector 10 is a device that can convert optical signals into electrical signals, such as a photomultiplier tube, photodiode, or phototransistor. The specific type of photodetector 10 can be flexibly selected according to the actual needs of the signal acquisition circuit 100 and the optical detection scenario, and is not strictly limited here. Figure 3 In the accompanying drawings, the photodetector device 10 is mainly illustrated using a photomultiplier tube (PMT) as an example.

[0102] The first input terminal of the first amplification module 20 is electrically connected to the output terminal of the photodetector device 10. The first amplification module 20 is used to amplify the electrical signal received at its first input terminal and then output it. In one example, the first amplification module 20 can be implemented using a transimpedance amplifier TIA, which consists of an operational amplifier OP1 and a feedback resistor Rf.

[0103] The first input terminal of the first amplification module 20 is the inverting input terminal of operational amplifier OP1, and the output current of photodetector 10 is directly input to the inverting input terminal of operational amplifier OP1. A feedback resistor is connected between the inverting input terminal OP1 and the output terminal of the operational amplifier. The first amplification module 20 has the characteristics of input differential amplification, and the output voltage of the first amplification module 20 is the sum of the voltage drop across the feedback resistor Rf due to the current received at the first input terminal and the voltage at the second input terminal.

[0104] In this application, at least one leakage current sampling module 30 is also provided in the signal acquisition circuit 100. For example... Figure 3 As shown, the number of leakage current sampling modules 30 is, for example, n, where n is a positive integer. Among the n leakage current sampling modules 30, i.e., leakage current sampling modules 1 to n, the first and second ends of any leakage current sampling module 30 are positioned on the electrical signal transmission path between the photodetector 10 and the first amplification module 20, and the third end of the leakage current sampling module 30 is electrically connected to the ground terminal GND. More specifically, the first end of the leakage current sampling module 30 is positioned closer to the photodetector 10 on the electrical signal transmission path than its second end.

[0105] In the at least one leakage current sampling module 30 described above, the target supply voltage range corresponding to different leakage current sampling modules 30 is different. For example, the target supply voltage range corresponding to the first leakage current sampling module 30 is -50V to -150V, the target supply voltage range corresponding to the second leakage current sampling module 30 is -150V to -250V, and the target supply voltage range corresponding to the nth leakage current sampling module 30 is -850V to -950V.

[0106] The specific working process of the leakage current sampling module 30 is described in detail below. During at least a portion of the leakage current sampling phase, the power supply terminal Vpmt supplies power to the photodetector device 10 using a voltage within the corresponding target supply voltage range. In this case, the leakage current sampling module 30, corresponding to the target supply voltage range, samples the target electrical signal in the electrical signal transmission path connected to its first terminal. After sampling the target electrical signal, a leakage current sampling signal is obtained and stored in the leakage current sampling module 30, which can be used for subsequent leakage current compensation.

[0107] For example, if the current target supply voltage range is -150V to -250V, the leakage current sampling module 2 samples the target electrical signal related to the leakage current to obtain the leakage current sampling electrical signal under the target supply voltage range of -150V to -250V, and the leakage current sampling electrical signal is stored in the leakage current sampling module 30.

[0108] It should be noted that during this period, the photodetector 10 is in a dark state and does not receive light signals. Therefore, the validity and accuracy of the sampled leakage current can be guaranteed.

[0109] Furthermore, the target electrical signal sampled above is related to the leakage current of the photodetector 10. In one example, the target electrical signal can be the leakage current output by the photodetector 10 during at least a portion of the leakage current sampling phase. In another example, the target electrical signal can also be the amplified voltage obtained after the leakage current is amplified by the first amplification module 20; this application does not impose strict limitations on this.

[0110] In one example, the leakage current sampling module 30 includes a storage device, such as a storage capacitor. The leakage current sampling electrical signal is stored in the storage device in the leakage current sampling module 30. When the leakage current sampling module 30 includes a storage capacitor, the aforementioned leakage current sampling electrical signal can be understood as the voltage signal of the storage capacitor after it has been charged by the target electrical signal.

[0111] During the operation phase following the leakage current sampling phase, the photodetector 10 operates under illumination, and the power supply terminal Vpmt supplies power to the photodetector 10 using the target supply voltage. The target supply voltage corresponds to a target supply voltage range. For example, if the current target supply voltage is -200V, the corresponding target supply voltage range is -150V to -250V, and the leakage current sampling module 30 corresponding to this target supply voltage range is the leakage current sampling module 2.

[0112] During this operating phase, the leakage current sampling module 30, corresponding to the target supply voltage range, compensates for the electrical signal in the electrical signal transmission path connected to its second terminal based on the pre-stored leakage current sampling electrical signal. Thus, based on the leakage current sampling module 30 corresponding to the current supply voltage, the output signal of the signal acquisition circuit 100 is calibrated, thereby achieving targeted compensation for leakage current in the detection current of the photodetector 10. More specifically, in one example, taking a voltage signal as an example during the operating phase, by transmitting the voltage signal from the leakage current sampling module 30 to the electrical signal transmission path at its second terminal, this voltage signal adjusts the output signal of the signal acquisition circuit 100, thereby achieving leakage current compensation for the photodetector 10 under different supply voltages.

[0113] It should be noted that the target supply voltage mentioned above corresponds to the target supply voltage range. By selecting the leakage current sampling electrical signal in the leakage current sampling module 30 corresponding to the supply voltage range for different supply voltages, leakage current compensation for the photodetector device 10 under different supply voltages can be achieved.

[0114] The correspondence here can be, for example, that the target supply voltage is within the target supply voltage range. In other examples, there are pre-set mapping rules between supply voltage and supply voltage range. The mapping interval corresponding to the target supply voltage is determined according to the mapping rules as the target supply voltage range, but the target supply voltage may not be within the target supply voltage range.

[0115] The leakage current compensation principle of the above-mentioned leakage current acquisition module will be explained below with a specific example. As an example, during the leakage current sampling stage, n leakage current sampling modules 30 correspond one-to-one with n target supply voltage ranges. When the photodetector device 10 is powered by voltages within the n target supply voltage ranges, leakage current sampling modules 1 to n sample the target electrical signals in the electrical signal transmission path connected to their first terminals, obtaining n leakage current sampling electrical signals corresponding one-to-one with the n target supply voltage ranges. Each of the leakage current sampling modules 1 to n stores a different leakage current sampling electrical signal. The leakage current sampling signal is, for example, a voltage signal.

[0116] Next, during the operation of the photodetector 10, the leakage current sampling module 30 corresponding to the target supply voltage range corresponding to the current target supply voltage of the photodetector 10 is determined, for example, leakage current sampling module n. The leakage current sampling module n transmits its pre-stored leakage current sampling electrical signal to the electrical signal transmission path connected to its second terminal. This is equivalent to making targeted adjustments to the final output signal of the signal acquisition circuit 100 based on the current supply voltage. Therefore, it can effectively achieve leakage current compensation for the photodetector 10 under different supply voltages, thereby improving the signal acquisition accuracy of the overall acquisition circuit, as well as enhancing the dynamic range and linearity of signal acquisition.

[0117] Please see below. Figure 4 and Figure 5 , Figure 4 This is a schematic diagram of the structure of a signal acquisition circuit 100 provided in another embodiment of this application. Figure 5 This is a schematic diagram of the signal acquisition circuit 100 provided in another embodiment of this application. As an optional embodiment, at least one leakage current sampling module 30 includes a first leakage current sampling module 31; the first end of the first leakage current sampling module 31 is electrically connected to the output end of the photodetector device 10, and the second end of the first leakage current sampling module 31 is electrically connected to the second input end of the first amplification module 20;

[0118] Any first leakage current sampling module 31 is used to: during at least a portion of the leakage current sampling period, when powering the photodetector 10 with a voltage within the corresponding target power supply voltage range, sample the first target electrical signal output by the photodetector 10 to obtain a leakage current sampling electrical signal.

[0119] And / or, the signal acquisition circuit 100 further includes a second amplification module 40, and at least one leakage current sampling module 30 includes a second leakage current sampling module 32; the first input terminal of the second amplification module 40 is electrically connected to the output terminal of the first amplification module 20, the first terminal of the second leakage current sampling module 32 is electrically connected to the output terminal of the first amplification module 20, and the second terminal of the second leakage current sampling module 32 is electrically connected to the second input terminal of the second amplification module 40;

[0120] The second amplification module 40 is used to amplify the electrical signal difference between its first input terminal and its second input terminal, and output the amplified electrical signal.

[0121] Any second leakage current sampling module 32 is used to: sample the second target electrical signal output by the first amplification module 20 to obtain a leakage current sampling electrical signal during at least a portion of the leakage current sampling period, when powering the photodetector device 10 with a voltage within the corresponding target power supply voltage range.

[0122] In this embodiment, at least one leakage current sampling module 30 includes a first leakage current sampling module 31. For example... Figure 4 As shown, taking at least one leakage current sampling module 30 including n first leakage current sampling modules 31 as an example. The first leakage current sampling modules 1 to n are all disposed between the input terminal of the photodetector device 10 and the second input terminal of the first amplification module 20, and the n first leakage current sampling modules 31 are connected in parallel.

[0123] In this way, during at least a portion of the leakage current sampling phase, when the photodetector 10 is powered by a voltage within the corresponding target supply voltage range, the first leakage current sampling module 31 samples the first target electrical signal (leakage current output by the photodetector 10) output by the photodetector 10 to obtain the leakage current sampling electrical signal.

[0124] During operation, when the power supply terminal Vpmt supplies power to the photodetector 10 using the target supply voltage, the photodetector 10 outputs a detection current, which includes the actual photocurrent and leakage current. The output terminal of the photodetector 10 is electrically connected to the first input terminal of the first amplification module 20, and the second terminal of the first leakage current sampling module 31 corresponding to the target supply voltage range is electrically connected to the second input terminal of the first amplification module 20.

[0125] In this way, the first amplification module 20 combines the detection current received at its first input terminal and the leakage current sampling signal received at its second input terminal, and outputs a voltage signal after leakage current compensation after amplification and conversion processing. That is to say, in this embodiment, the leakage current sampling signal provided to the second input terminal of the first amplification module 20 by the corresponding first leakage current sampling module 31 realizes the voltage adjustment of the output terminal of the first amplification module 20, thereby realizing the compensation for the leakage current generated by the photodetector device 10 in the signal acquisition circuit 100 under different supply voltages.

[0126] In other embodiments, such as Figure 5 As shown, the signal acquisition circuit 100 further includes a second amplification module 40, and at least one leakage current sampling module 30 includes a second leakage current sampling module 32. In one example, the second amplification module 40 can be as follows: Figure 5 The differential amplifier circuit shown implements differential amplification. The differential amplifier circuit includes resistors R1, R2, R3, and R4, as well as operational amplifier OP2.

[0127] Taking at least one leakage current sampling module 30 including n second leakage current sampling modules 32 as an example, the first input terminal of the second amplification module 40 is electrically connected to the output terminal of the first amplification module 20, and the second leakage current sampling modules 1 to n are all set between the output terminal of the first amplification module 20 and the second input terminal of the second amplification module 40, and the n second leakage current sampling modules 32 are connected in parallel.

[0128] In this way, during at least a portion of the leakage current sampling phase, when power is supplied to the photodetector 10 using a voltage within the corresponding target supply voltage range, the first amplification module 20 first amplifies the leakage current output by the photodetector 10 and converts it into a voltage output. Then, the second leakage current sampling module 32, corresponding to the target supply voltage range, samples the second target electrical signal (the output voltage of the first amplification module 20) output from the output terminal of the first amplification module 20, thereby obtaining the leakage current sampling electrical signal.

[0129] During operation, when the power supply terminal Vpmt supplies power to the photodetector 10 using the target supply voltage, the photodetector 10 outputs a detection current, which includes the actual photocurrent and leakage current. The first amplification module 20 amplifies this detection current, converts it into a voltage, and outputs it to the first input terminal of the second amplification module 40.

[0130] In this scenario, the corresponding second leakage current sampling module 32 transmits the pre-stored leakage current sampling signal to the second input terminal of the second amplification module 40. Thus, by providing the corresponding leakage current sampling signal to the second input terminal of the second amplification module 40, targeted voltage adjustment of the output terminal of the second amplification module 40 under different supply voltages is achieved, thereby compensating for the leakage current generated by the photodetector device 10 in the signal acquisition circuit 100 under different supply voltages. Furthermore, the aforementioned second leakage current sampling module 32 also helps to effectively achieve operational amplifier noise filtering compensation for the first amplification module 20 itself, thereby facilitating the acquisition of signals with low noise and high dynamic range.

[0131] It should be added that, in some embodiments, the above-mentioned at least one leakage current sampling module 30 may simultaneously include a first leakage current sampling module 31 and a second leakage current sampling module 32. The first leakage current sampling module 31 and the second leakage current sampling module 32 can work together to achieve more accurate leakage current compensation, thereby ensuring the reliability and accuracy of the output signal of the signal acquisition circuit 100. This application does not make strict limitations here.

[0132] Please see below. Figure 6 or Figure 7 , Figure 6 and Figure 7 These are schematic diagrams of the signal acquisition circuit 100 provided in another embodiment of this application. Figure 6 or Figure 7 As shown, in an optional embodiment, the leakage current sampling module 30 includes:

[0133] The first switching unit 101, the first end of the first switching unit 101 is the first end of the leakage current sampling module 30;

[0134] The sampling unit 103 has its first terminal electrically connected to the second terminal of the first switching unit 101, and its second terminal electrically connected to the ground terminal GND.

[0135] The second switching unit 102 has its first end electrically connected to the first end of the sampling unit 103, and its second end is the second end of the leakage current sampling module 30.

[0136] During at least a portion of the leakage current sampling phase, when power is supplied to the photodetector 10 using a voltage within the corresponding target supply voltage range, the first switching unit 101 is turned on, the second switching unit 102 is turned off, and the sampling unit 103 is used to sample the target electrical signal transmitted by the first switching unit 101 to obtain the leakage current sampling electrical signal.

[0137] During the working phase, the first switching unit 101 is turned off, the second switching unit 102 is turned on, and the sampling unit 103 is used to compensate for the leakage current in the detection current of the photodetector based on the leakage current sampling electrical signal.

[0138] As an example, such as Figure 6 or Figure 7 As shown, when the number of leakage current sampling modules 30 is n, the first switching unit 101 in each leakage current sampling module 30 can be implemented by switches SW1_1 to SW1_n, the second switching unit 102 in each leakage current sampling module 30 can be implemented by switches SW2_1 to SW2_n, and the sampling unit 103 in each leakage current sampling module 30 can be implemented by sampling capacitors C1 to Cn.

[0139] The switches SW1_1 to SW1_n and SW2_1 to SW2_n can be implemented using transistors such as bipolar junction transistors (BJTs), insulated gate bipolar transistors (IGBTs), and metal-oxide-semiconductor field-effect transistors (MOSFETs), or they can be implemented using relays or integrated analog switch chips. These switches can be controlled to turn on using hardware circuitry or software. The sampling unit 103 can also be implemented using memory devices other than the aforementioned sampling capacitors; no strict limitation is imposed here.

[0140] In a specific implementation, when the leakage current sampling module 30 is working, the leakage current sampling module 30, based on the first switching unit 101 and the second switching unit 102, realizes the switching of different working states during the leakage current sampling stage and the working stage.

[0141] During at least a portion of the leakage current sampling phase, when the photodetector 10 is powered by a voltage within the corresponding target supply voltage range, the first switching unit 101 in the corresponding leakage current sampling module 30 is turned on, and the second switching unit 102 is turned off, forming a leakage current sampling branch consisting of the turned-on first switching unit 101 and the sampling unit 103. When the first switching unit 101 is turned on, the sampling unit 103 samples the target electrical signal transmitted by the first switching unit 101 to obtain a leakage current sampling electrical signal.

[0142] During operation, when the power supply terminal Vpmt supplies power to the photodetector 10 using the target supply voltage, in the leakage current sampling module 30 corresponding to the target supply voltage range, the first switching unit 101 is off, and the second switching unit 102 is on, forming a discharge branch consisting of the sampling unit 103 and the on-state second switching unit 102. With the second switching unit 102 on, the sampling unit 103 compensates for the leakage current in the photodetector's detection current based on the stored leakage current sampling signal.

[0143] In one example, such as Figure 6 As shown, taking the aforementioned first leakage current sampling module 31 as an example, during at least a portion of the leakage current sampling phase, the first switching unit 101 in the corresponding first leakage current sampling module 31 is turned on, and the sampling unit 103 samples and stores the leakage current output from the output terminal of the photodetector device 10, thereby obtaining a leakage current sampling electrical signal. During the working phase, the second switching unit 102 in the corresponding first leakage current sampling module 31 is turned on, transmitting the leakage current sampling electrical signal stored in the sampling unit 103 to the second input terminal of the first amplification module 20, so as to make targeted adjustments to the output voltage of the first amplification module 20, thereby realizing the adjustment of the overall output signal of the signal acquisition circuit 100 and realizing targeted leakage current compensation for the photodetector device 10 under different supply voltages.

[0144] In another example, such as Figure 7 As shown, taking the aforementioned second leakage current sampling module 32 as an example, during at least a portion of the leakage current sampling phase, the first switching unit 101 in the corresponding second leakage current sampling module 32 is turned on, and the sampling unit 103 samples and stores the output voltage of the output terminal of the first amplification module 20, thereby obtaining the leakage current sampling electrical signal. During the working phase, the second switching unit 102 in the corresponding second leakage current sampling module 32 is turned on, and the leakage current sampling electrical signal in the sampling unit 103 is transmitted to the second input terminal of the second amplification module 40 through the second switching unit 102, so as to make targeted adjustments to the output voltage of the second amplification module 40, thereby realizing the adjustment of the overall output signal of the signal acquisition circuit 100, and thus realizing targeted leakage current compensation for the photodetector device 10 under different supply voltages.

[0145] Furthermore, considering the influence of operational amplifier noise in the first amplification module 20 itself, this application, through the second leakage current sampling module 32 located after the first amplification module 20, can fully filter out the operational amplifier noise of the first amplification module 20 itself based on the sampling unit 103 in the second leakage current sampling module 32, thereby reducing the impact of operational amplifier noise on the signal acquisition link. Therefore, it helps to further improve the signal acquisition accuracy and ultimately achieve low noise and high dynamic range signal acquisition.

[0146] Please see below. Figure 8 , Figure 8 This is a schematic diagram of the structure of a signal acquisition circuit 100 provided in another embodiment of this application. For example... Figure 8 As shown, in an optional embodiment, at least one leakage current sampling module 30 includes a second leakage current sampling module 32, and the second leakage current sampling module 32 further includes:

[0147] The first isolation unit 104 has its first input terminal electrically connected to its output terminal, and its second input terminal electrically connected to the second terminal of the first switching unit 101 and the first terminal of the leakage current sampling module 30, respectively.

[0148] The signal acquisition circuit 100 also includes:

[0149] The second isolation unit 105 has its first input terminal electrically connected to its output terminal, and its second input terminal electrically connected to the output terminal of the first amplification module 20.

[0150] In this embodiment, the second leakage current sampling module 32, in addition to the aforementioned first switching unit 101, sampling unit 103, and second switching unit 102, may also include a first isolation unit 104 and a second isolation unit 105. The first isolation unit 104 and the second isolation unit 105 can be voltage followers, non-inverting amplifiers, or other high-impedance input amplifiers, etc., and this application does not impose strict limitations here. As an example, such as... Figure 8 As shown, in n second leakage current sampling modules 32, the first isolation unit 104 in each second leakage current sampling module 32 includes voltage followers A1 to An, and the second isolation unit 105 is a voltage follower A0.

[0151] The aforementioned first isolation unit 104 and second isolation unit 105 possess high input impedance and low output impedance, ensuring complete and reliable signal transmission. In the cascaded structure of multi-stage amplification modules consisting of the first amplification module 20 and the second amplification module 40, the first isolation unit 104 and the second isolation unit 105 can effectively reduce the load effect of the preceding amplification module. Furthermore, the second isolation unit 105 can also significantly reduce leakage current from the sampling unit 103 to the second amplification module 40, thereby ensuring the stability and accuracy of the signal during transmission.

[0152] It should be noted that, considering the influence of different circuit structures on the received signal (such as parasitic capacitance and parasitic resistance), the first isolation unit 104 and the second isolation unit 105 maintain the same circuit structure. In this way, the deviation of the received signal at the second input terminal of the second amplification module 40 caused by the influence of the first isolation unit 104 will be canceled out by the deviation of the received signal at the first input terminal of the second amplification module 40 caused by the influence of the second isolation unit 105.

[0153] Therefore, by symmetrically setting the isolation units at the two input terminals of the second amplification module 40, it is equivalent to introducing the influence of the devices symmetrically, so that these influences cancel each other out at the two input terminals, which can ensure the accuracy and reliability of the output signal of the second amplification module 40.

[0154] Please see below. Figure 9 , Figure 9 This is a schematic diagram of the signal acquisition circuit 100 provided in another embodiment of this application. As an optional embodiment, such as... Figure 9 As shown, the second leakage current sampling module 32 also includes:

[0155] The third switching unit 106 has its first end electrically connected to the first input end of the first isolation unit 104, and its second end electrically connected to the output end of the first isolation unit 104.

[0156] During the working phase, the third switch unit 106 is turned on, connecting the first input terminal of the first isolation unit 104 with the output terminal of the first isolation unit 104.

[0157] In specific operation, during the working phase, the third switch unit 106 in the corresponding second leakage current sampling module 32 is turned on to connect the first input terminal of the first isolation unit 104 with the output terminal of the first isolation unit 104, thereby ensuring reliable signal output from the first isolation unit 104. During the leakage current sampling phase, the on / off state of the third switch unit 106 can be flexibly set, without strict limitations.

[0158] In this embodiment, by setting a third switching unit 106, both the first input terminal and the second input terminal of the first isolation unit 104 are equipped with switching devices. When symmetrical switching devices are set at the two input terminals, these switching devices will introduce the same parasitic effects (such as parasitic capacitance, parasitic resistance, etc.). These effects are symmetrical in the two input segments of the first isolation unit 104, and therefore can cancel each other out.

[0159] Thus, this embodiment achieves the cancellation of the parasitic effects of the switching devices of the first switching unit 101 by utilizing the parasitic effects brought about by the switching devices of the third switching unit 106, thereby effectively improving signal stability and reliability and reducing noise caused by the asymmetric switching device configuration.

[0160] Please see below. Figure 10 or Figure 11 , Figure 10 and Figure 11 These are schematic diagrams of a signal acquisition circuit 100 provided in another embodiment of this application. As an optional embodiment, the signal acquisition circuit 100 further includes a third amplification module 50.

[0161] like Figure 10 As shown, when the signal acquisition circuit 100 does not include the second amplification module 40, the input terminal of the third amplification module 50 is electrically connected to the output terminal of the first amplification module 20, and the output terminal of the third amplification module 50 is electrically connected to the acquisition signal output terminal.

[0162] Alternatively, please see Figure 11 When the signal acquisition circuit 100 includes the second amplification module 40, the input terminal of the third amplification module 50 is electrically connected to the output terminal of the second amplification module 40, and the output terminal of the third amplification module 50 is electrically connected to the acquisition signal output terminal.

[0163] The third amplification module 50 is used to amplify the voltage signal received at its input terminal and then output it.

[0164] In this embodiment, by setting a third amplification module 50, the signal can be further amplified and output to increase the signal strength, thereby facilitating the signal processing requirements of subsequent circuits. The third amplification module 50, for example, is a gain amplifier (Gain), and its specific design and configuration can be tailored to actual signal processing or transmission needs; no strict limitations are imposed here.

[0165] It should be added that if the signal acquisition circuit 100 already includes the second amplification module 40, the third amplification module 50 may not be required, in order to reduce the overall circuit cost.

[0166] As an optional embodiment, the number of leakage current sampling modules 30 in at least one leakage current sampling module 30 is n, where n is a positive integer;

[0167] During the leakage current sampling stage, n leakage current sampling modules 30 are used to sample the target electrical signal of the photodetector device 10 under n power supply voltage ranges in a time-division manner, so as to obtain n leakage current sampling electrical signals corresponding to the n power supply voltage ranges. The n power supply voltage ranges correspond one-to-one with the n leakage current sampling modules 30, and the n power supply voltage ranges include the target power supply voltage range.

[0168] During the working phase, when the photodetector 10 is powered by the target supply voltage, the leakage current in the detection current of the photodetector is compensated based on the leakage current sampling electrical signal in the leakage current sampling module 30 corresponding to the target supply voltage range.

[0169] This embodiment describes the operating timing of the above n leakage current sampling modules 30.

[0170] Specifically, n target supply voltage ranges are pre-defined, and each of the n leakage current sampling modules 30 corresponds one-to-one with one of the n target supply voltage ranges. For example, the target supply voltage range corresponding to leakage current sampling module 1 is -50V to -150V, the target supply voltage range corresponding to leakage current sampling module 2 is -150V to -250V, and the target supply voltage range corresponding to leakage current sampling module n is -850V to -950V. The number of 'n' can be selected according to different supply voltage conditions of the photodetector device 10 and actual needs.

[0171] During the leakage current sampling stage, when the photodetector 10 is powered by voltages within n target supply voltage ranges (e.g., the median voltage within the range), n leakage current sampling modules 30 are used to sample the target electrical signals of the photodetector 10 under the n supply voltage ranges in a time-division manner, obtaining n leakage current sampling electrical signals corresponding to the n target supply voltage ranges. The n leakage current sampling electrical signals are stored in their respective leakage current sampling modules 30, and can be used in subsequent working stages to achieve targeted leakage current compensation under different power supply conditions based on the different leakage current sampling electrical signals stored in different leakage current sampling modules 30.

[0172] Next, during the operation of the photodetector 10, the leakage current sampling module 30 corresponding to the target power supply voltage range corresponding to the current target power supply voltage of the photodetector 10 is determined, and the leakage current sampling module 30 is adjusted to transmit leakage current sampling electrical signals in order to achieve targeted leakage current correction under the current target power supply voltage.

[0173] For example, if the current target supply voltage is -200V, the target supply voltage range corresponding to this target supply voltage is determined to be -150V to -250V. The leakage current sampling module 30 corresponding to the -150V to -250V supply voltage range is the leakage current sampling module 2. In this case, the leakage current sampling module 2 is adjusted to perform leakage current compensation. The leakage current sampling electrical signal stored in the leakage current sampling module 2 is transmitted to the electrical signal transmission path connected to its second terminal, thereby realizing targeted adjustment of the output signal of the signal acquisition circuit 100 under the target supply voltage.

[0174] Overall, the leakage current sampling timing provided in this embodiment can effectively compensate for the leakage current of the photodetector device 10 under different supply voltages, thereby improving the signal acquisition accuracy of the overall acquisition circuit and enhancing the dynamic range and linearity of signal acquisition.

[0175] More specifically, please see below. Figure 12 , Figure 13 as well as Figure 14 , Figure 12 , Figure 13 as well as Figure 14 This is a timing diagram of a leakage current sampling module 30 provided in one embodiment of this application. As an optional embodiment, the number of leakage current sampling modules 30 in at least one leakage current sampling module 30 is n, where n is a positive integer;

[0176] During the leakage current sampling stage, the first switching unit 101 in the n leakage current sampling modules 30 is turned on in a time-division manner, the second switching unit 102 in the n leakage current sampling modules 30 is turned off, and the sampling unit 103 in the n leakage current sampling modules 30 is used to sample the target electrical signal of the photodetector device 10 under n power supply voltage ranges in a time-division manner, so as to obtain n leakage current sampling electrical signals corresponding to the n power supply voltage ranges. The n power supply voltage ranges correspond one-to-one with the n leakage current sampling modules 30, and the n power supply voltage ranges include the target power supply voltage range.

[0177] During the working phase, when the photodetector 10 is powered by the target supply voltage, the first switching unit 101 in the leakage current sampling module 30 corresponding to the target supply voltage range is turned off, the second switching unit 102 is turned on, and the sampling unit 103 is used to compensate for the leakage current in the detection current of the photodetector based on the corresponding leakage current sampling electrical signal.

[0178] In this embodiment, when the specific leakage current sampling module 30 is working, the leakage current sampling module 30, based on the first switching unit 101 and the second switching unit 102, realizes the switching of different working states under the leakage current sampling stage and the working stage.

[0179] During the leakage current sampling phase, when the photodetector 10 is powered by voltages within n target supply voltage ranges (e.g., the median voltage within the range), the n leakage current sampling modules 30 are turned on in a time-division manner to sample the target electrical signals related to leakage current within different supply voltage ranges. The n leakage current sampling electrical signals are stored in their respective leakage current sampling modules 30 and can be used for leakage current compensation in subsequent operating phases.

[0180] During the leakage current sampling phase, the second switching unit 102 in each leakage current sampling module 30 is turned off. It should be noted that, in the case where the leakage current sampling module 30 also includes a third switching unit 106, the third switching unit 106 in each leakage current sampling module 30 is turned off during the leakage current sampling phase.

[0181] During the operating phase, the first switching unit 101 in each leakage current sampling module 30 is turned off. When the power supply terminal Vpmt supplies power to the photodetector 10 using the target supply voltage, the second switching unit 102 in the leakage current sampling module 30 corresponding to the target supply voltage range is turned on, forming a discharge branch formed by the sampling unit 103 and the turned-on second switching unit 102. When the second switching unit 102 is turned on, the sampling unit 103 compensates for the leakage current in the detection current of the photodetector based on the stored leakage current sampling electrical signal.

[0182] In a specific example, the first switching unit 101 in each leakage current sampling module 30 is implemented using switches SW1_1 to SW1_n, the second switching unit 102 in each leakage current sampling module 30 is implemented using switches SW2_1 to SW2_n, and the sampling unit 103 in each leakage current sampling module 30 is implemented using sampling capacitors C1 to Cn. The first amplification module 20 uses a transimpedance amplifier (TIA), the second amplification module 40 uses a differential amplifier circuit, and the third amplification module 50 uses a gain amplifier.

[0183] Combination Figure 10 The signal acquisition circuit 100 shown is as follows: Figure 12 As shown, during the leakage current sampling stage, the corresponding switches SW1_1 to SW1_n are closed briefly in a time-division multiplexing manner to store the leakage currents of the photodetector device 10 under different power supply voltage ranges into the sampling capacitors C1 to Cn after each switch, thereby achieving pre-storage of different leakage currents. During this stage, SW2_1 to SW2_n are turned off.

[0184] In the actual work phase, such as Figure 13 or Figure 14 As shown, switches SW1_1 to SW1_n are turned off. Based on the current supply voltage range of the photodetector 10, the corresponding switches among SW2_1 to SW2_n are closed. Then, the leakage current sampling signal stored in the sampling capacitor Ci is input to the TIA at the back end. Leakage current correction is performed using the differential input of the TIA, and the signal is amplified, thereby achieving leakage current calibration of the overall output signal of the signal acquisition circuit 100.

[0185] Or, combined with Figure 11The signal acquisition circuit 100 shown closes the corresponding switches SW1_1 to SW1_n for a short time during the leakage current sampling stage. This allows the leakage currents of the photodetector device 10 under different supply voltage ranges to be amplified by the first-stage TIA and stored in the sampling capacitors C1 to Cn after each switch, thereby achieving pre-storage of different leakage currents. During this stage, SW2_1 to SW2_n are turned off.

[0186] In the actual work phase, such as Figure 13 or Figure 14 As shown, switches SW1_1 to SW1_n are turned off. Based on the current supply voltage range of the photodetector 10, the corresponding switches among SW2_1 to SW2_n are closed. Then, the leakage current sampling signal stored in the i-th sampling capacitor Ci of C1 to Cn is connected to the second amplification module 40 at the back end. The differential amplification characteristics of the second amplification module 40 are used to filter out and amplify the leakage current sampling signal, thereby realizing the leakage current calibration of the overall output signal of the signal acquisition circuit 100.

[0187] It should be noted that different leakage current compensation sequences can be used depending on the changes in the target supply voltage of the photodetector 10 during the operating phase. For example, such as Figure 13 As shown, when the target power supply voltage of the photodetector 10 changes continuously during the working phase, the switches SW2_1 to SW2_n are closed sequentially, so that different sampling capacitors among the sampling capacitors C1 to Cn are connected to the second amplification module 40 at the back end, so as to achieve targeted leakage current compensation under different power supply voltages.

[0188] For example, such as Figure 14 As shown, during the working phase, the target power supply voltage of the photodetector device 10 is stable. In this case, the corresponding switch SW2_n is closed, so that the sampling capacitor Cn is connected to the second amplification module 40 at the back end, so as to achieve targeted leakage current compensation under the current target power supply voltage.

[0189] It is understood that the embodiments provided in this application... Figure 12 , Figure 13 as well as Figure 14 The switch control timing shown is only one possible example. In other embodiments, the above switch timing can be flexibly adjusted according to actual conditions and needs. This application does not impose any specific limitations on it.

[0190] It should be added that, in some embodiments, the target supply voltage of the actual photodetector 10 during the operating phase can be predetermined, and the corresponding leakage current sampling module 30 can be specifically controlled to perform early leakage current sampling according to the target supply voltage range corresponding to the target supply voltage. The other leakage current sampling modules 30 may not perform leakage current sampling during the early leakage current sampling phase, so as to reduce the leakage current sampling power consumption of multiple leakage current sampling modules 30 in the early stage and save leakage current sampling time.

[0191] Please see below. Figure 15 , Figure 15 This is a schematic diagram of the signal acquisition circuit 100 provided in another embodiment of this application. As an optional embodiment, such as... Figure 15 As shown, the signal acquisition circuit 100 also includes:

[0192] The current regulation module 60 has its control terminal electrically connected to the drive voltage terminal Vcon, its first terminal electrically connected to the reference voltage terminal Vref, and its second terminal electrically connected to the output terminal of the photodetector device 10.

[0193] The current adjustment module 60 is used to adjust the current signal received at the first input terminal of the first amplification module 20 under the control of the adjustable voltage provided by the drive voltage terminal Vcon and / or the reference voltage terminal Vref.

[0194] In this embodiment, by setting a current adjustment module 60 on the current output path of the photodetector 10, the current flowing into the first input terminal of the first amplification module 20 is corrected by the current adjustment module 60 shunting the detection current, thereby realizing the calibration of the leakage current generated by the photodetector 10.

[0195] In actual setup, the voltages provided by the drive voltage terminal Vcon and / or the reference voltage terminal Vref can be adjusted according to the power supply voltage of the photodetector 10. The current adjustment module 60 can be adjusted based on the on-state of the current adjustment module 60 provided by the drive voltage terminal Vcon and / or the reference voltage terminal Vref. This on-state affects the proportion of the probe current shunted to the current adjustment module 60, thereby indirectly controlling the current flowing into the first input terminal of the first amplification module 20 and calibrating the leakage current generated by the photodetector 10.

[0196] In one embodiment, if the leakage current in the photodetector 10 is large, the voltages provided by the drive voltage terminal Vcon and / or the reference voltage terminal Vref are adjusted to ensure that the current adjustment module 60 is more fully open. This allows more current from the detection current to be diverted to the current adjustment module 60. Consequently, the current received at the first input terminal of the first amplification module 20 is the current after leakage current calibration, thus ensuring the accuracy of the output electrical signal from the signal acquisition circuit 100.

[0197] As an optional embodiment, continue as follows Figure 15 As shown, more specifically, the current regulation module 60 includes a transistor Q1;

[0198] The gate of transistor Q1 is electrically connected to the driving voltage terminal Vcon, the source of transistor Q1 is electrically connected to the reference voltage terminal Vref, and the drain of transistor Q1 is electrically connected to the output terminal of photodetector 10.

[0199] The transistor Q1 mentioned above includes, for example, bipolar junction transistors (BJTs), insulated-gate bipolar junction transistors (IGBTs), and metal-oxide-semiconductor field-effect transistors (MOSFETs), and is not strictly limited here. Different transistors Q1 achieve current regulation through different control methods and operating principles. The selection of a suitable transistor Q1 type depends on the specific application requirements and circuit design.

[0200] In one example, as shown in the figure, transistor Q1 is an N-type MOSFET. The transistor Q1 can adjust its on-state under the control of different gate voltages and / or source voltages, thereby controlling the current shunted to transistor Q1 by the probe current. In turn, the leakage current in the probe current output by the photodetector 10 is calibrated by correcting the current flowing into the first input terminal of the first amplification module 20 through the shunting.

[0201] Please see below. Figure 16 , Figure 16 This is a schematic diagram of the signal acquisition circuit 100 provided in another embodiment of this application. As an optional embodiment, such as... Figure 16 As shown, the signal acquisition circuit 100 also includes a switch control module 70, which includes at least one comparator CMP1 to CMPn and a target encoder ENC.

[0202] At least one comparator CMP1 to CMPn has its first input terminal electrically connected to the target node N, and at least one comparator CMP1 to CMPn has its second input terminal electrically connected to at least one reference voltage terminal Vcmp1 to Vcmpn. The target node N is a node between two resistors R5 and R6 connected in series between the power supply terminal Vpmt and the ground terminal GND. At least one reference voltage terminal Vcmp1 to Vcmpn provides different reference voltages.

[0203] The output of at least one comparator CMP1 to CMPn is electrically connected to at least one input pin of the target encoder ENC, or the output of at least some of the comparators CMP1 to CMPn is electrically connected to the input pin of the target encoder ENC via an inverter INV.

[0204] At least one output pin of the target encoder ENC is electrically connected to the control terminal of the first switching unit 101 or the second switching unit 102 in at least one leakage current sampling module 30. The target encoder ENC is used to provide a corresponding turn-on signal or turn-off signal to the control terminal of the first switching unit 101 or the second switching unit 102 in at least one leakage current sampling module 30 according to the level signal received by at least one input pin.

[0205] In this embodiment, the selection control of the switching units in the signal acquisition circuit 100 is achieved by setting a switch control module 70. Specifically, the switch control module 70 may include at least one comparator CMP1 to CMPn and a target encoder ENC.

[0206] Alternatively, in some other embodiments, the switch control module 70 may further include inverters INV1 to INVn. Inverters INV1-n are disposed between the output of any comparator CMP and the input pin of the target encoder ENC to achieve the flipping of the output level of comparator CMP.

[0207] It should be noted that the number and configuration of inverters can be flexibly selected based on the control method of different switching units, and are not strictly limited here.

[0208] The aforementioned target encoder ENC is, for example, a 3-8 encoder or a 3-8 decoder. For instance, taking a 3-8 encoder as an example, the target encoder ENC includes eight input pins. These input pins are directly electrically connected to the outputs of the corresponding comparators CMP1-n or electrically connected via inverters INV1-n. The target encoder ENC generates corresponding binary codes based on the high and low levels received from different input pins to control the on / off states of different switching units.

[0209] In a specific implementation, for example, the switch control module 70 selects comparators CMP1 to CMPn and the target encoder ENC to implement hardware selection control of the switch unit in the signal acquisition circuit 100. Different reference voltages corresponding to the comparators CMP1 to CMPn are pre-set according to different target supply voltage ranges. When the actual power supply terminal Vpmt changes, the potential of the target node N obtained by voltage division through resistors R5 and R6 changes. In this case, different comparators CMP1 to CMPn can output corresponding high or low levels based on the voltage comparison result between the current potential of the target node N and its corresponding reference voltage.

[0210] In this way, the target encoder (ENC) outputs a corresponding binary code based on the high and low voltage levels received by its multiple input pins. Different binary codes correspond to different switching units that need to be turned on. Based on this, the on or off control of the corresponding switching units can be achieved.

[0211] It should be noted that after voltage division, the potential of the target node N will be more closely matched with the operating voltage characteristics of the comparator, thus helping to ensure the accuracy of the comparison results and the device safety of the comparator.

[0212] Furthermore, in some embodiments, to facilitate the target encoder ENC to more accurately control the conduction or cutoff of different switching units, control devices such as control chips can be further provided between the target encoder ENC and the control terminal of the switching unit.

[0213] It should also be noted that, considering the different operating states of the first switching unit 101 and the second switching unit 102 in the leakage current sampling module 30, two sets of switch control modules 70 can be provided. One set of switch control modules 70 is used to control the on / off state of at least one first switching unit 101, and the other set of switch control modules 70 is used to control the on / off state of at least one second switching unit 102.

[0214] In the case where the leakage current sampling module 30 also includes a third switching unit 106, the on / off state of at least one second switching unit 102 and the third switching unit 106 can be synchronously controlled by the same switching control module 70, without strict limitation.

[0215] Please see below. Figure 17 , Figure 17 This is a schematic diagram of the signal acquisition circuit 100 provided in another embodiment of this application. As an optional embodiment, the first amplification module 20 includes a transimpedance amplifier (TIA).

[0216] The second amplification module 40 includes a differential amplification circuit or a fully differential amplification circuit.

[0217] The aforementioned second amplification module 40 can be used as the aforementioned appendix Figure 15 The differential amplifier circuit in the middle can also be as follows: Figure 17 The fully differential amplifier circuit shown in this application does not impose strict limitations on the circuit structure of the second amplifier module 40, as long as the second amplifier module 40 has differential amplification function.

[0218] It is understood that the above are merely examples and do not constitute a substantial limitation on the signal acquisition circuit 100 protected in this application. It should be noted that, in addition to the devices listed above, the signal acquisition circuit 100 in this application may also include other circuit elements, which together constitute various types of signal acquisition circuits 100; this application does not impose specific limitations on these.

[0219] In summary, the leakage current acquisition and storage scheme and timing design of the photodetector 10 in this application embodiment provide a photodetector acquisition scheme based on correlation dual sampling technology. By storing the leakage current and using differential subtraction, the influence of leakage current and chip noise on the signal acquisition link is removed, thus effectively improving the dynamic range and linearity of signal acquisition.

[0220] Based on the signal acquisition circuit provided in the above embodiments, and with the same inventive concept, this application also provides a control method for a signal acquisition circuit corresponding to the above signal acquisition circuit. The following describes... Figure 18 The control method of the signal acquisition circuit is described in detail.

[0221] Figure 18 A flowchart illustrating a control method for a signal acquisition circuit according to an embodiment of this application is shown. This method is applied to a signal acquisition circuit as described in any of the foregoing embodiments of this application. Figure 18 The control method of the signal acquisition circuit shown includes:

[0222] S1810, during at least a portion of the leakage current sampling phase, when powering the photodetector with a voltage within the target power supply voltage range, the leakage current sampling module corresponding to the target power supply voltage range is controlled to sample the target electrical signal in the electrical signal transmission path connected to the first terminal of the leakage current sampling module to obtain the leakage current sampling electrical signal.

[0223] S1820, during the working phase, when the target supply voltage is used to supply power to the photodetector device, based on the leakage current sampling signal, controls the leakage current sampling module corresponding to the target supply voltage range to compensate the electrical signal in the electrical signal transmission path connected to the second terminal of the leakage current sampling module. The target supply voltage range is different for different leakage current sampling modules, and the target supply voltage corresponds to the target supply voltage range.

[0224] In this application, the control method of the signal acquisition circuit can be implemented by devices or equipment with control functions such as field-programmable gate arrays (FPGAs), microcontroller units (MCUs), or programmable logic controllers (PLCs), and is not strictly limited here.

[0225] The control method for a signal acquisition circuit provided in this application has the beneficial effects of the signal acquisition circuit provided in this application. The specific implementation method can be referred to the specific description of the signal acquisition circuit in the above embodiments. For the sake of brevity, this embodiment will not be described again here.

[0226] Based on the control method of the signal acquisition circuit provided in the above embodiments, and with the same inventive concept, this application also provides a control device for a signal acquisition circuit corresponding to the control method of the above signal acquisition circuit. The following describes... Figure 19 The control equipment for the signal acquisition circuit is described in detail.

[0227] Please see below. Figure 19 , Figure 19 This is a schematic diagram of the structure of a control device for a signal acquisition circuit provided in an embodiment of this application.

[0228] The control device for the signal acquisition circuit may include a processor 1901 and a memory 1902 storing computer program instructions.

[0229] Specifically, the processor 1901 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0230] Memory 1902 may include mass storage for data or instructions. For example, and not limitingly, memory 1902 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 1902 may include removable or non-removable (or fixed) media. Where appropriate, memory 1902 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 1902 is non-volatile solid-state memory.

[0231] Memory may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, and electrical, optical, or other physical / tangible memory storage devices. Therefore, typically, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the methods according to one aspect of this disclosure.

[0232] The processor 1901 reads and executes computer program instructions stored in the memory 1902 to implement any of the signal acquisition circuit control methods in the above embodiments.

[0233] In one example, the control device for the data signal acquisition circuit may further include a communication interface 1903 and a bus 1910. For example, Figure 19 As shown, the processor 1901, memory 1902, and communication interface 1903 are connected through bus 1910 and complete communication with each other.

[0234] The communication interface 1903 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0235] Bus 1910 includes hardware, software, or both, that couples components of a control device for signal acquisition circuitry together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 1910 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, any suitable bus or interconnect is contemplated herein.

[0236] The control device of the signal acquisition circuit executes the control method of the signal acquisition circuit in the embodiments of this application, thereby realizing the control method of the signal acquisition circuit described in the embodiments of this application.

[0237] Furthermore, in conjunction with the control method of the signal acquisition circuit in the above embodiments, this application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the control methods of the signal acquisition circuit in the above embodiments.

[0238] Based on the control method of the signal acquisition circuit in the above embodiments, this application provides a computer program product. When the instructions in the computer program product are executed by the processor of an electronic device, the electronic device executes the control method of the signal acquisition circuit provided in any one of the above embodiments of this application.

[0239] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0240] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0241] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0242] It should be clarified that the various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. According to the embodiments described above, these embodiments do not exhaustively describe all details, nor do they limit this application to only the specific embodiments described. Obviously, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to make good use of this application and modifications based on it. This application is limited only by the claims and their full scope and equivalents.

[0243] Those skilled in the art will understand that the above embodiments are exemplary and not restrictive. Different technical features appearing in different embodiments can be combined to achieve beneficial effects. Based on a study of the drawings, specification, and claims, those skilled in the art should be able to understand and implement other variations of the disclosed embodiments. In the claims, the term "comprising" does not exclude other structures; the quantity refers to "one" but does not exclude multiple; the terms "first" and "second" are used to identify names and not to indicate any particular order. Any reference numerals in the claims should not be construed as limiting the scope of protection. The appearance of certain technical features in different dependent claims does not mean that these technical features cannot be combined to achieve beneficial effects.

[0244] This document uses specific examples to illustrate the principles and implementation methods of this application. The examples are merely for the purpose of helping to understand the method and core ideas of this application. The above are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, and the existence of an infinite number of specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the concept and technical solution of this application to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A signal acquisition circuit, characterized in that, The signal acquisition circuit includes: A photodetector is used to detect an optical signal under the power supply voltage provided at the power supply terminal and to output the detection current corresponding to the optical signal. A first amplification module, wherein the first input terminal of the first amplification module is electrically connected to the output terminal of the photodetector, and the first amplification module is used to amplify the electrical signal received at its first input terminal and then output it. At least one leakage current sampling module, wherein the first and second ends of the leakage current sampling module are disposed on the electrical signal transmission path where the photodetector and the first amplification module are located, and the third end of the leakage current sampling module is electrically connected to the ground terminal. Any of the aforementioned leakage current sampling modules is used to: during at least a portion of the leakage current sampling phase, when the photodetector is powered by a voltage within the corresponding target supply voltage range, sample the target electrical signal in the electrical signal transmission path connected to the first terminal of the leakage current sampling module to obtain a leakage current sampling electrical signal. During the working phase, when the photodetector is powered by the target supply voltage, the electrical signal in the electrical signal transmission path connected to the second terminal of the leakage current sampling module is compensated based on the leakage current sampling electrical signal. The target supply voltage range is different for different leakage current sampling modules, and the target supply voltage corresponds to the target supply voltage range.

2. The circuit according to claim 1, characterized in that, The at least one leakage current sampling module includes a first leakage current sampling module; a first end of the first leakage current sampling module is electrically connected to the output end of the photodetector, and a second end of the first leakage current sampling module is electrically connected to the second input end of the first amplification module. Any of the first leakage current sampling modules is configured to: during at least a portion of the leakage current sampling phase, when the photodetector is powered by a voltage within the corresponding target supply voltage range, sample the first target electrical signal output by the photodetector to obtain the leakage current sampling electrical signal. And / or, the signal acquisition circuit further includes a second amplification module, and the at least one leakage current sampling module includes a second leakage current sampling module; the first input terminal of the second amplification module is electrically connected to the output terminal of the first amplification module, the first terminal of the second leakage current sampling module is electrically connected to the output terminal of the first amplification module, and the second terminal of the second leakage current sampling module is electrically connected to the second input terminal of the second amplification module; The second amplification module is used to amplify the electrical signal difference between its first input terminal and its second input terminal, and output the amplified electrical signal. Any of the second leakage current sampling modules is used to: sample the second target electrical signal output by the first amplification module to obtain the leakage current sampling electrical signal during at least a portion of the leakage current sampling period, while supplying power to the photodetector with a voltage within the corresponding target power supply voltage range.

3. The circuit according to claim 2, characterized in that, The leakage current sampling module includes: The first switching unit, wherein the first terminal of the first switching unit is the first terminal of the leakage current sampling module; A sampling unit, wherein a first end of the sampling unit is electrically connected to a second end of the first switching unit, and a second end of the sampling unit is electrically connected to a grounding end; The second switching unit has a first terminal electrically connected to the first terminal of the sampling unit, and the second terminal of the second switching unit is the second terminal of the leakage current sampling module. During at least a portion of the leakage current sampling phase, when the photodetector is powered by a voltage within the corresponding target supply voltage range, the first switching unit is turned on and the second switching unit is turned off. The sampling unit is used to sample the target electrical signal transmitted by the first switching unit to obtain the leakage current sampling electrical signal. During the operating phase, the first switching unit is turned off, the second switching unit is turned on, and the sampling unit is used to compensate for the leakage current in the detection current of the photodetector based on the leakage current sampling electrical signal.

4. The circuit according to claim 3, characterized in that, The at least one leakage current sampling module includes the second leakage current sampling module, and the second leakage current sampling module further includes: The first isolation unit has a first input terminal electrically connected to the output terminal of the first isolation unit, and a second input terminal of the first isolation unit electrically connected to the second terminal of the first switching unit and the first terminal of the leakage current sampling module, respectively. The signal acquisition circuit also includes: The second isolation unit has its first input terminal electrically connected to its output terminal, and its second input terminal electrically connected to the output terminal of the first amplification module.

5. The circuit according to claim 4, characterized in that, The second leakage current sampling module also includes: The third switching unit has a first terminal electrically connected to the first input terminal of the first isolation unit, and a second terminal electrically connected to the output terminal of the first isolation unit. During the operating phase, the third switch unit is turned on, connecting the first input terminal of the first isolation unit with the output terminal of the first isolation unit.

6. The circuit according to claim 2, characterized in that, The signal acquisition circuit also includes a third amplification module; In the case where the signal acquisition circuit does not include the second amplification module, the input terminal of the third amplification module is electrically connected to the output terminal of the first amplification module, and the output terminal of the third amplification module is electrically connected to the acquisition signal output terminal. Alternatively, if the signal acquisition circuit includes the second amplification module, the input terminal of the third amplification module is electrically connected to the output terminal of the second amplification module, and the output terminal of the third amplification module is electrically connected to the acquired signal output terminal. The third amplification module is used to amplify the voltage signal received at its input terminal and then output it.

7. The circuit according to any one of claims 1-6, characterized in that, The number of leakage current sampling modules in the at least one leakage current sampling module is n, where n is a positive integer; During the leakage current sampling stage, n leakage current sampling modules are used to sample the target electrical signal of the photodetector device under n power supply voltage ranges in a time-division manner, so as to obtain n leakage current sampling electrical signals corresponding to the n power supply voltage ranges. The n power supply voltage ranges correspond one-to-one with the n leakage current sampling modules, and the n power supply voltage ranges include the target power supply voltage range. During operation, when the photodetector is powered by the target supply voltage, the leakage current in the detection current of the photodetector is compensated based on the leakage current sampling signal in the leakage current sampling module corresponding to the target supply voltage range.

8. The circuit according to any one of claims 2-6, characterized in that, The number of leakage current sampling modules in the at least one leakage current sampling module is n, where n is a positive integer; During the leakage current sampling phase, the first switching units in the n leakage current sampling modules are turned on in a time-division manner, and the second switching units in the n leakage current sampling modules are turned off. The sampling units in the n leakage current sampling modules are used to sample the target electrical signal of the photodetector under n power supply voltage ranges in a time-division manner, so as to obtain n leakage current sampling electrical signals corresponding to the n power supply voltage ranges. The n power supply voltage ranges correspond one-to-one with the n leakage current sampling modules, and the n power supply voltage ranges include the target power supply voltage range. During the working phase, when the target power supply voltage is used to power the photodetector, the first switch unit in the leakage current sampling module corresponding to the target power supply voltage range is turned off and the second switch unit is turned on, and the sampling unit is used to compensate for the leakage current in the detection current of the photodetector based on the corresponding leakage current sampling electrical signal.

9. The circuit according to any one of claims 1-6, characterized in that, The signal acquisition circuit also includes: A current regulation module, wherein the control terminal of the current regulation module is electrically connected to the drive voltage terminal, the first terminal of the current regulation module is electrically connected to the reference voltage terminal, and the second terminal of the current regulation module is electrically connected to the output terminal of the photodetector. The current adjustment module is used to adjust the current signal received at the first input terminal of the first amplification module under the control of the adjustable voltage provided at the driving voltage terminal and / or the reference voltage terminal.

10. The circuit according to claim 9, characterized in that, The current regulation module includes transistors; The gate of the transistor is electrically connected to the driving voltage terminal, the source of the transistor is electrically connected to the reference voltage terminal, and the drain of the transistor is electrically connected to the output terminal of the photodetector.

11. The circuit according to any one of claims 2-6, characterized in that, The signal acquisition circuit also includes a switch control module, which includes at least one comparator and a target encoder. The first input terminal of the at least one comparator is electrically connected to the target node, and the second input terminal of the at least one comparator is electrically connected to at least one reference voltage terminal. The target node is a node between two resistors connected in series between the power supply terminal and the ground terminal. The reference voltages provided by the at least one reference voltage terminal are different. The output of the at least one comparator is electrically connected to at least one input pin of the target encoder, or at least some of the comparators are electrically connected to the input pins of the target encoder via inverters. At least one output pin of the target encoder is electrically connected to the control terminal of the first or second switching unit in the at least one leakage current sampling module. The target encoder is used to provide a corresponding on or off signal to the control terminal of the first or second switching unit in the at least one leakage current sampling module according to the level signal received by the at least one input pin.

12. The circuit according to any one of claims 2-6, characterized in that, The first amplification module includes a transimpedance amplifier; The second amplification module includes a differential amplifier circuit or a fully differential amplifier circuit.

13. A control method for a signal acquisition circuit, characterized in that, The signal acquisition circuit described in any one of claims 1-12 is further characterized by a control method comprising: During at least a portion of the leakage current sampling phase, when powering the photodetector with a voltage within the target power supply voltage range, the leakage current sampling module corresponding to the target power supply voltage range is controlled to sample the target electrical signal in the electrical signal transmission path connected to the first terminal of the leakage current sampling module to obtain the leakage current sampling electrical signal. During the working phase, when the photodetector is powered by the target supply voltage, the leakage current sampling module corresponding to the target supply voltage range is controlled based on the leakage current sampling signal to compensate the electrical signal in the electrical signal transmission path connected to the second terminal of the leakage current sampling module. The target supply voltage range is different for different leakage current sampling modules, and the target supply voltage corresponds to the target supply voltage range.

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