Light source drive circuit and light source system

Abstract

Provided in the embodiments of the present application are a light source drive circuit and a light source system. The light source drive circuit comprises: a series voltage reference, a constant-current control module, a switch module, a sampling module, a power supply module and a light source module, wherein the series voltage reference is used for outputting a preset reference voltage signal to the constant-current control module; the sampling module is used for converting an operating current of the light source module into a first voltage signal, and transmitting the first voltage signal to the constant-current control module; and the constant-current control module is used for comparing the first voltage signal with the reference voltage signal, and when a voltage difference between the first voltage signal and the reference voltage signal is greater than a preset threshold value, adjusting a second voltage signal output by the constant-current control module itself, such that the switch module adjusts its own conduction degree on the basis of the second voltage signal, until the voltage difference between the first voltage signal and the reference voltage signal is not greater than the preset threshold value.

Description

A light source driving circuit and light source system

[0001] This application claims priority to Chinese Patent Application No. 202510370278.6, filed on March 27, 2025, entitled "A Light Source Driving Circuit and Light Source System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of electronic technology, and in particular to a light source driving circuit and a light source system. Background Technology

[0003] In current detection and analysis instrument systems, the circuit structure shown in Figure 1 is typically used to drive the deuterium lamp to ensure that the brightness of the light source remains stable after the deuterium lamp is lit, that is, to ensure that the current flowing through the anode of the deuterium lamp is stable.

[0004] The deuterium lamp driving circuit shown in Figure 1 includes a deuterium lamp, a voltage source, a reference voltage source, a constant current control module, a sampling resistor, and a switching transistor. The voltage source generates a suitable DC voltage to power the anode of the deuterium lamp. The sampling resistor converts the current flowing through the deuterium lamp into a sampling voltage. The reference voltage source provides a stable reference voltage to the constant current control module, which is a given value of the current flowing through the deuterium lamp. The constant current control module outputs a control signal to the switching transistor based on the sampling voltage and the reference voltage. The switching transistor adjusts the current flowing through the deuterium lamp based on the output of the constant current control module.

[0005] However, in the deuterium lamp driving circuit shown in Figure 1, a parallel regulated voltage reference is used as the reference voltage source. The stability of the parallel regulated voltage reference is poor, which may lead to poor stability of the deuterium lamp driving circuit and the light source brightness of the deuterium lamp after it is lit cannot be kept stable. Summary of the Invention

[0006] The purpose of this application is to provide a light source driving circuit and a light source system to improve the stability of the light source driving circuit. The specific technical solution is as follows:

[0007] In a first aspect, embodiments of this application provide a light source driving circuit, the circuit comprising:

[0008] The system comprises a series voltage reference, a constant current control module, a switching module, a sampling module, a power supply module, and a light source module. The input terminal of the series voltage reference is connected to the power supply module, the output terminal of the series voltage reference is connected to the constant current control module, and the reference potential terminal of the series voltage reference is connected to the sampling module. The constant current control module is also connected to the sampling module, the switching module, and the power supply module. The switching module, the sampling module, and the light source module are connected in series, and any one of these modules is connected to the power supply module. The series voltage reference outputs a preset reference voltage signal to the constant current control module. The sampling module converts the operating current of the light source module into a first voltage signal and transmits the first voltage signal to the constant current control module. The constant current control module compares the first voltage signal with the reference voltage signal. If the voltage difference between the first voltage signal and the reference voltage signal is greater than a preset threshold, it adjusts its own output second voltage signal so that the switching module adjusts its conduction level based on the second voltage signal until the voltage difference between the first voltage signal and the reference voltage signal is not greater than the preset threshold.

[0009] In one possible implementation, the output terminal of the series voltage reference is connected to the first input terminal of the constant current control module, and the reference potential terminal of the series voltage reference is connected to the second terminal of the sampling module and the light source module, respectively; the second input terminal of the constant current control module is connected to the first terminal of the sampling module and the second terminal of the switching module, respectively; the output terminal of the constant current control module is connected to the control terminal of the switching module, and the first terminal of the switching module is connected to the power supply module; the positive terminal of the power supply of the constant current control module is connected to the power supply module.

[0010] In one possible implementation, the power supply module includes a DC voltage source and an isolated power supply; the positive input terminal of the isolated power supply is connected to the power supply terminal, and the positive output terminal of the isolated power supply is connected to the positive power supply terminal of the constant current control module and the input terminal of the series voltage reference, respectively; the DC voltage source is connected to the first terminal of the switching module and the power supply terminal, respectively; the isolated power supply is used to supply power to the constant current control module and the series voltage reference, respectively; the DC voltage source is used to supply power to the light source module.

[0011] In one possible implementation, the power supply module includes a DC voltage source; the DC voltage source is connected to the first terminal of the switching module, the positive power terminal of the constant current control module, the input terminal of the series voltage reference, and the power supply terminal, respectively; the DC voltage source is used to supply power to the constant current control module, the series voltage reference, and the light source module, respectively.

[0012] In one possible implementation, the constant current control module includes a first amplifier, a first resistor, and a first capacitor; the non-inverting input of the first amplifier is connected to the output of the series voltage reference, the inverting input of the first amplifier is connected to the second terminal of the first capacitor and the second terminal of the first resistor, the output of the first amplifier is connected to the first terminal of the first capacitor and the control terminal of the switching module, and the positive power supply terminal of the first amplifier is connected to the power supply module; the first terminal of the first resistor is connected to the first terminal of the sampling module and the second terminal of the switching module.

[0013] In one possible implementation, the sampling module includes a second resistor; the first end of the second resistor is connected to the second end of the switching module and the second input end of the constant current control module, respectively, and the second end of the second resistor is connected to the reference potential end of the light source module and the series voltage reference.

[0014] In one possible implementation, the switching module includes an N-type switching transistor; the control terminal of the N-type switching transistor is connected to the output terminal of the constant current control module, the first terminal of the N-type switching transistor is connected to the power supply module, and the second terminal of the N-type switching transistor is connected to the second input terminal of the constant current control module and the first terminal of the sampling module, respectively.

[0015] In one possible implementation, the negative power supply terminal of the first amplifier is connected to the reference potential terminal of the series voltage reference, the second terminal of the sampling module, and the light source module, respectively.

[0016] In one possible implementation, the negative input terminal of the isolation power supply is grounded; the negative output terminal of the isolation power supply is connected to the reference potential terminal of the series voltage reference, the second terminal of the sampling module, and the light source module, respectively.

[0017] In one possible implementation, the power supply mode of the power supply terminal is a DC power supply mode.

[0018] Secondly, embodiments of this application provide a light source system, the light source system including any of the light source driving circuits described in the first aspect above.

[0019] Beneficial effects of the embodiments in this application:

[0020] This application provides a light source driving circuit and a light source system. The light source driving circuit includes: a series voltage reference, a constant current control module, a switching module, a sampling module, a power supply module, and a light source module. The input terminal of the series voltage reference is connected to the power supply module, the output terminal of the series voltage reference is connected to the constant current control module, and the reference potential terminal of the series voltage reference is connected to the sampling module. The constant current control module is also connected to the sampling module, the switching module, and the power supply module. The switching module, the sampling module, and the light source module are connected in series, and any one of the switching module, the sampling module, and the light source module is connected to the power supply module. The series voltage reference is used to output a preset reference voltage signal to the constant current control module. The sampling module is used to convert the operating current of the light source module into a first voltage signal and transmit the first voltage signal to the constant current control module. The constant current control module is used to compare the first voltage signal with the reference voltage signal. If the voltage difference between the first voltage signal and the reference voltage signal is greater than a preset threshold, it adjusts its own output second voltage signal so that the switching module adjusts its conduction degree based on the second voltage signal until the voltage difference between the first voltage signal and the reference voltage signal is not greater than the preset threshold. By using a series voltage reference as the reference voltage source (the stability of a series voltage reference is higher than that of a parallel voltage reference), the input terminal of the series voltage reference is connected to the power supply module, the output terminal of the series voltage reference is connected to the constant current control module, and the reference potential terminal of the series voltage reference is connected to the sampling module, thereby improving the stability of the light source driving circuit and ensuring that the brightness of the light source remains highly stable.

[0021] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. The drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other embodiments based on these drawings.

[0023] Figure 1 is a schematic diagram of a deuterium lamp driving circuit in related technologies;

[0024] Figure 2 is a schematic diagram of the first structure of the light source driving circuit provided in the embodiment of this application;

[0025] Figure 3 is a schematic diagram of a second structure of the light source driving circuit provided in an embodiment of this application;

[0026] Figure 4 is a schematic diagram of a third structure of the light source driving circuit provided in an embodiment of this application;

[0027] Figure 5 is a schematic diagram of the fourth structure of the light source driving circuit provided in the embodiment of this application;

[0028] Figure 6 is a schematic diagram of a light source system provided in an embodiment of this application;

[0029] Figure 7 is a schematic diagram of the fifth structure of the light source driving circuit provided in the embodiment of this application;

[0030] Figure 8 is a schematic diagram of the sixth structure of the light source driving circuit provided in the embodiments of this application;

[0031] Figure 9 is a schematic diagram of the seventh structure of the light source driving circuit provided in the embodiments of this application;

[0032] Figure 10 is a schematic diagram of the eighth structure of the light source driving circuit provided in the embodiment of this application;

[0033] Figure 11 is a schematic diagram of the ninth structure of the light source driving circuit provided in the embodiment of this application;

[0034] Figure 12 is a schematic diagram of the tenth structure of the light source driving circuit provided in the embodiment of this application;

[0035] Figure 13 is a schematic diagram of the eleventh structure of the light source driving circuit provided in the embodiment of this application;

[0036] Figure 14 is a schematic diagram of the twelfth structure of the light source driving circuit provided in the embodiment of this application;

[0037] Figure 15 is a schematic diagram of the thirteenth structure of the light source driving circuit provided in the embodiment of this application. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in this application are within the scope of protection of this application.

[0039] In current detection and analysis instrument systems, the circuit structure shown in Figure 1 is typically used to drive the deuterium lamp to ensure that the brightness of the light source remains stable after the deuterium lamp is lit, that is, to ensure that the current flowing through the anode of the deuterium lamp is stable.

[0040] The deuterium lamp driving circuit shown in Figure 1 includes a deuterium lamp, a voltage source, a reference voltage source, a constant current control module, a sampling resistor, and a switching transistor. The voltage source generates a suitable DC voltage to power the anode of the deuterium lamp. The sampling resistor converts the current flowing through the deuterium lamp into a sampling voltage. The reference voltage source provides a stable reference voltage to the constant current control module, which is a given value of the current flowing through the deuterium lamp. The constant current control module outputs a control signal to the switching transistor based on the sampling voltage and the reference voltage. The switching transistor adjusts the current flowing through the deuterium lamp based on the output of the constant current control module.

[0041] When the deuterium lamp is lit normally, the current flows out from the higher potential end of the voltage source, through the sampling resistor and the switching transistor, and into the anode of the deuterium lamp. The power supply provides DC power, and the negative terminal of the power supply, the lower potential end of the voltage source, and one end of the cathode of the deuterium lamp are at the same potential (for example, they can be grounded to GND). The reference voltage source and the constant current control module are powered by the voltage source through an electrical connection. When the deuterium lamp is lit normally, the higher potential end of the sampling resistor is at the same potential as the higher potential end of the reference voltage source.

[0042] However, in the deuterium lamp driving circuit shown in Figure 1, a parallel regulated voltage reference is used as the reference voltage source (it has two ports, a positive terminal and a negative terminal, with the positive terminal connected to the voltage source and the sampling resistor respectively, and the negative terminal connected to the constant current control module and ground respectively). The stability of the parallel regulated voltage reference is poor, which may lead to poor stability of the deuterium lamp driving circuit, and the brightness of the light source after the deuterium lamp is lit cannot be kept stable.

[0043] Furthermore, in the deuterium lamp driving circuit shown in Figure 1, the reference voltage source, the constant current control module, and the deuterium lamp are all powered by the voltage source. The power supply current loop of the reference voltage source and the constant current control module can easily affect the stability of the deuterium lamp anode current.

[0044] The switching transistors can only be P-type switching transistors with poor performance and difficult to obtain (such as PNP transistors, PMOS transistors, etc.), which affects the overall performance of the deuterium lamp driving circuit.

[0045] To improve at least one of the above problems, embodiments of this application provide a light source driving circuit and a light source system.

[0046] Next, the light source driving circuit 1 provided in the embodiments of this application will be described in detail. Referring to Figure 2, which is a schematic diagram of the first structure of the light source driving circuit 1 provided in the embodiments of this application, the light source driving circuit 1 includes:

[0047] Series-connected voltage reference 11, constant current control module 12, switching module 13, sampling module 14, power supply module 15, and light source module 16;

[0048] The input terminal of the series voltage reference 11 is connected to the power supply module 15, the output terminal of the series voltage reference 11 is connected to the first input terminal of the constant current control module 12, and the reference potential terminal of the series voltage reference 11 is connected to the second terminal of the sampling module 14 and the light source module 16, respectively. The second input terminal of the constant current control module 12 is connected to the first terminal of the sampling module 14 and the second terminal of the switching module 13, respectively. The output terminal of the constant current control module 12 is connected to the control terminal of the switching module 13, and the first terminal of the switching module 13 is connected to the power supply module 15. The positive terminal of the power supply of the constant current control module 12 is connected to the power supply module 15.

[0049] The series voltage reference 11 is used to output a preset reference voltage signal to the first input terminal of the constant current control module 12;

[0050] The sampling module 14 is used to convert the operating current of the light source module 16 (the current flowing through the light source module 16) into a first voltage signal and transmit the first voltage signal to the second input terminal of the constant current control module 12.

[0051] The constant current control module 12 is used to compare the first voltage signal with the reference voltage signal. When the voltage difference between the first voltage signal and the reference voltage signal is greater than a preset threshold, the module 12 adjusts the second voltage signal at its own output terminal so that the switching module 13 adjusts its own conduction degree based on the second voltage signal until the voltage difference between the first voltage signal and the reference voltage signal is not greater than the preset threshold.

[0052] The sampling module 14 converts the operating current of the light source module 16 into a voltage signal, thereby providing feedback on the actual operating current of the light source module 16. The sampling module 14 can be a sampling resistor or other types of current-collecting devices; this application does not specifically limit its use.

[0053] The series-type voltage reference 11 is used to output a highly stable preset reference voltage signal, which provides a precise current setting reference (constant current reference value) for the constant current control module 12.

[0054] The constant current control module 12 compares the sampled voltage signal (first voltage signal, i.e., the voltage drop of the sampled module 14) of the sampling module 14 with the reference voltage signal. Based on the voltage difference between the two, it dynamically adjusts the conduction degree of the switch module 13 so that the operating current of the light source module 16 tends to a certain value, i.e., maintains a constant current.

[0055] In one example, if the reference voltage signal is 1.2V and the sampling resistor is 4Ω, the constant current can be calculated to be 300mA.

[0056] The preset threshold can be set according to the actual situation of the circuit. In one example, the preset threshold can be 0.05V.

[0057] In one example, the preset threshold can be 0V. When the preset threshold is 0V, the constant current control module 12 compares the first voltage signal with the reference voltage signal. If the voltage value of the first voltage signal is not equal to the voltage value of the reference voltage signal, it adjusts the second voltage signal at its own output terminal so that the switching module 13 adjusts its conduction level based on the second voltage signal until the voltage value of the first voltage signal is equal to the voltage value of the reference voltage signal. Specifically, if the first voltage signal is greater than the reference voltage signal, the constant current control module 12 will adjust the second voltage signal at its own output terminal to decrease, the conduction level of the switching module 13 will decrease, and the operating current of the light source module 16 will decrease until the voltage value of the first voltage signal is equal to the voltage value of the reference voltage signal; if the first voltage signal is less than the reference voltage signal, the constant current control module 12 will adjust the second voltage signal at its own output terminal to increase, the conduction level of the switching module 13 will increase, and the operating current of the light source module 16 will increase until the voltage value of the first voltage signal is equal to the voltage value of the reference voltage signal.

[0058] The series-type voltage reference 11 mainly includes the following units: 1. A reference voltage source, typically using a bandgap reference structure or a Zener diode, to provide a highly stable reference voltage; 2. A comparator amplifier, used to compare the sampled voltage with the reference voltage, and output a control signal based on the difference between the sampled voltage and the reference voltage to control the voltage adjustment unit; 3. A voltage adjustment unit, composed of a power transistor or a field-effect transistor, dynamically adjusts its own voltage drop according to the control signal to maintain the voltage stability at the output of the series-type voltage reference 11; 4. A sampling circuit, typically using a voltage divider network composed of resistors or potentiometers, to proportionally feed the voltage at the output of the series-type voltage reference 11 back to the comparator amplifier.

[0059] The series-type voltage reference 11 includes three ports: an input port, an output port, and a reference potential port. The input port is used to connect to the power supply module 15 to provide the operating voltage for the series-type voltage reference 11; the output port is used to output a high-precision, high-stability preset reference voltage signal; and the reference potential port is used to provide a reference potential, ensuring that the voltages at the input and output ports are referenced to a common reference point, while also forming a complete current loop.

[0060] Compared to the parallel-regulated voltage reference, the series-regulated voltage reference 11 has higher accuracy and stability, which can improve the accuracy and stability of the light source driving circuit 1, so that the light source brightness of the light source module 16 can be kept highly accurate and highly stable.

[0061] The reference potential terminal of the series voltage reference 11 is connected to the second terminal of the sampling module 14, that is, the reference potential terminal of the series voltage reference 11 and the second terminal of the sampling module 14 are kept at the same potential (one end of the light source module 16). The beneficial effects are as follows: the measurement of the reference voltage signal and the sampling voltage signal (first voltage signal) are both referenced to the same potential, which can ensure that the voltage difference between the reference voltage signal and the sampling voltage signal input to the constant current control module 12 only reflects the actual current deviation, which can improve the accuracy of current detection; through the equipotential design, the constant current control module 12 can directly compare the reference voltage signal and the sampling voltage signal without additional compensation for the influence of the potential difference on the comparison result, simplifying the control logic.

[0062] In the light source driving circuit 1 shown in Figure 2, the power supply module 15 supplies power to the series voltage reference 11, the light source module 16, and the constant current control module 12 respectively.

[0063] In this embodiment, a series voltage reference is used as the reference voltage source (the accuracy and stability of the series voltage reference are higher than those of the parallel voltage reference). The input terminal of the series voltage reference 11 is connected to the power supply module 15, the output terminal of the series voltage reference 11 is connected to the first input terminal of the constant current control module 12, and the reference potential terminal of the series voltage reference 11 is connected to the second terminal of the sampling module 14 and the light source module 16, respectively. This improves the accuracy and stability of the light source driving circuit 1, so that the light source brightness of the light source module 16 remains highly accurate and highly stable.

[0064] In one possible implementation, referring to FIG3, the power module 15 includes a DC voltage source 151 and an isolated power supply 152;

[0065] The positive input terminal of the isolation power supply 152 is connected to the power supply terminal, and the positive output terminal of the isolation power supply 152 is connected to the positive power supply terminal of the constant current control module 12 and the input terminal of the series voltage reference 11, respectively.

[0066] The DC voltage source 151 is connected to the first terminal and the power supply terminal of the switch module 13, respectively.

[0067] The isolation power supply 152 is used to supply power to the constant current control module 12 and the series voltage reference 11 respectively;

[0068] The DC voltage source 151 is used to power the light source module 16.

[0069] In one example, the DC voltage source 151 can be a DC-DC converter boost circuit that boosts the 24V DC voltage at the power supply end to the 60V-150V DC voltage required by the light source module 16.

[0070] In one example, the isolation power supply 152 can be a low-power standard isolation power supply module that converts 24V DC to 12V DC, providing 12V DC voltage to the constant current control module 12 and the series voltage reference 11.

[0071] In this embodiment, the constant current control module 12 and the series voltage reference 11 are powered by an isolation power supply 152, and the light source module 16 is powered by a DC voltage source 151. The power supply circuits of the constant current control module 12 and the series voltage reference 11 are separated from the power supply circuit of the light source module 16. Compared with related technologies where the reference voltage source, constant current control module, and deuterium lamp are all powered by a voltage source, the influence of the power supply circuits of the series voltage reference 11 and the constant current control module 12 on the current stability of the light source module 16 is reduced. Furthermore, since the isolation power supply 152 completely isolates its input and output terminals through a transformer, there is no direct electrical connection between the input and output terminals. Therefore, using the isolation power supply 152 (in a non-electrically connected manner) to power the constant current control module 12 and the series voltage reference 11 can improve the reliability, safety, anti-interference ability, and stability of the light source driving circuit 1.

[0072] In one possible implementation, referring to FIG4, the power module 15 includes a DC voltage source 151;

[0073] The DC voltage source 151 is connected to the first terminal of the switching module 13, the positive power supply terminal of the constant current control module 12, the input terminal of the series voltage reference 11, and the power supply terminal, respectively.

[0074] The DC voltage source 151 is used to supply power to the constant current control module 12, the series voltage reference 11, and the light source module 16, respectively.

[0075] In this embodiment, the constant current control module 12, the series voltage reference 11, and the light source module 16 are powered by the same voltage source, which simplifies the circuit structure of the light source driving circuit 1 and reduces the cost.

[0076] In one possible implementation, referring to FIG5, the constant current control module 12 includes a first amplifier A1, a first resistor R1, and a first capacitor C1;

[0077] The non-inverting input terminal + of the first amplifier A1 is connected to the output terminal of the series voltage reference 11, the inverting input terminal - of the first amplifier A1 is connected to the second terminal of the first capacitor C1 and the second terminal of the first resistor R1, the output terminal OUT of the first amplifier A1 is connected to the first terminal of the first capacitor C1 and the control terminal of the switching module 13, and the positive power supply terminal VDD of the first amplifier A1 is connected to the power supply module 15.

[0078] The first end of the first resistor R1 is connected to the first end of the sampling module 14 and the second end of the switching module 13, respectively.

[0079] The first capacitor C1 is the feedback capacitor, and the first resistor R1 is the input resistor.

[0080] In the constant current control module 12, the input first voltage signal (sampled voltage signal) generates an input current through the first resistor R1. The input current charges the first capacitor C1. The voltage of the first capacitor C1 is the difference between the voltage at the output terminal OUT of the first amplifier A1 and the voltage at the inverting input terminal -. Combining this with the "virtual short" characteristic of the first amplifier A1, the relationship between the first voltage signal, the reference voltage signal, and the second voltage signal is as follows:

[0081] Where R1 represents the first resistor, C1 represents the first capacitor, t represents time, Vc(t) represents the second voltage signal, Vref(t) is the reference voltage signal, and Vs(t) represents the first voltage signal.

[0082] The constant current control module 12 compares the first voltage signal with the reference voltage signal and adjusts the output according to the difference. When the first voltage signal is greater than the reference voltage signal, the second voltage signal output by the constant current control module 12 decreases linearly with time, the conduction degree of the switch module 13 decreases, and the operating current of the light source module 16 decreases until the voltage value of the first voltage signal is equal to the voltage value of the reference voltage signal. When the first voltage signal is less than the reference voltage signal, the second voltage signal output by the constant current control module 12 increases linearly with time, the conduction degree of the switch module 13 increases, and the operating current of the light source module 16 increases until the voltage value of the first voltage signal is equal to the voltage value of the reference voltage signal.

[0083] In one possible implementation, referring to FIG5, the sampling module 14 includes a second resistor R2;

[0084] The first end of the second resistor R2 is connected to the second end of the switch module 13 and the second input end of the constant current control module 12, respectively. The second end of the second resistor R2 is connected to the reference potential end of the light source module 16 and the series voltage reference 11, respectively.

[0085] The second resistor R2 is a sampling resistor. The sampling resistor is a precision resistor used to convert the operating current of the light source module 16 into a voltage signal (the voltage drop across the sampling resistor), thereby achieving accurate feedback of the actual operating current of the light source module 16.

[0086] The reference potential terminal of the series voltage reference 11 is connected to the second terminal of the second resistor R2, that is, the reference potential terminal of the series voltage reference 11 and the second terminal of the second resistor R2 are kept at the same potential (one end of the light source module 16). The beneficial effects are as follows: the measurement of the reference voltage signal and the sampling voltage signal (first voltage signal) are both referenced to the same potential, which can ensure that the voltage difference between the reference voltage signal and the sampling voltage signal input to the constant current control module 12 only reflects the actual current deviation, which can improve the accuracy of current detection; through the equipotential design, the constant current control module 12 can directly compare the reference voltage signal and the sampling voltage signal without additional compensation for the influence of the potential difference on the comparison result, simplifying the control logic.

[0087] In one possible implementation, referring to FIG5, the switching module 13 includes an N-type switching transistor M1;

[0088] The control terminal of the N-type switch M1 is connected to the output terminal of the constant current control module 12, the first terminal of the N-type switch M1 is connected to the power supply module 15, and the second terminal of the N-type switch M1 is connected to the second input terminal of the constant current control module 12 and the first terminal of the sampling module 14.

[0089] Compared to the P-type switching transistors used in related technologies, which have poor performance, the N-type switching transistor M1 used in this embodiment has high driving capability, fast switching speed and low switching loss, which can improve the response speed of the switching module 13 and improve the reliability of the entire light source driving circuit 1.

[0090] The N-type switch M1 can be an N-type field-effect transistor (NMOS) or other types of N-type switch transistors; this application does not specifically limit it in this regard.

[0091] In one possible implementation, referring to FIG5, the negative power supply terminal VEE of the first amplifier A1 is connected to the reference potential terminal of the series voltage reference 11, the second terminal of the sampling module 14, and the light source module 16, respectively.

[0092] In one possible implementation, referring to Figure 3, the negative input terminal of the isolation power supply 152 is grounded to GND.

[0093] In one possible implementation, referring to FIG3, the negative output terminal of the isolation power supply 152 is connected to the reference potential terminal of the series voltage reference 11, the second terminal of the sampling module 14, and the light source module 16, respectively.

[0094] In one possible implementation, the power supply mode of the power supply terminal is a DC power supply mode.

[0095] The light source driving circuit 1 in this embodiment of the application may also include, as shown in Figure 7:

[0096] Series-connected voltage reference 11, constant current control module 12, switching module 13, sampling module 14, power supply module 15, and light source module 16;

[0097] The input terminal of the series voltage reference 11 is connected to the power supply module 15, and the output terminal of the series voltage reference 11 is connected to the first input terminal of the constant current control module 12. The reference potential terminal of the series voltage reference 11 is connected to the second terminal of the sampling module 14 and the power supply module 15, respectively. The second input terminal of the constant current control module 12 is connected to the first terminal of the sampling module 14 and the second terminal of the switching module 13, respectively. The output terminal of the constant current control module 12 is connected to the control terminal of the switching module 13. The positive and negative terminals of the power supply of the constant current control module 12 are connected to the power supply module 15, respectively. The first terminal of the switching module 13 is connected to the light source module 16, and the light source module 16 is also connected to the power supply module 15.

[0098] The series voltage reference 11 is used to output a preset reference voltage signal to the first input terminal of the constant current control module 12;

[0099] The sampling module 14 is used to convert the operating current of the light source module 16 (the current flowing through the light source module 16) into a first voltage signal and transmit the first voltage signal to the second input terminal of the constant current control module 12.

[0100] The constant current control module 12 is used to compare the first voltage signal with the reference voltage signal. When the voltage difference between the first voltage signal and the reference voltage signal is greater than a preset threshold, the module 12 adjusts the second voltage signal at its own output terminal so that the switching module 13 adjusts its own conduction degree based on the second voltage signal until the voltage difference between the first voltage signal and the reference voltage signal is not greater than the preset threshold.

[0101] In this embodiment, a series voltage reference is used as the reference voltage source (the accuracy and stability of the series voltage reference are higher than those of the parallel voltage reference). The input terminal of the series voltage reference 11 is connected to the power supply module 15, the output terminal of the series voltage reference 11 is connected to the first input terminal of the constant current control module 12, and the reference potential terminal of the series voltage reference 11 is connected to the second terminal of the sampling module 14 and the light source module 16, respectively. This improves the accuracy and stability of the light source driving circuit 1, so that the light source brightness of the light source module 16 remains highly accurate and highly stable.

[0102] In one possible implementation, the switching module 13 is a P-type switching transistor M2, the constant current control module 12 is located on the cathode side of the light source module 16, and the series-type voltage reference 11 outputs a positive voltage. Referring to Figure 8, the power supply module 15 includes a first DC voltage source 153, a second DC voltage source 154, and a third DC voltage source 155; the constant current control module 12 includes a first amplifier A1, a first resistor R1, a first capacitor C1, and a polarity reversal circuit 121; the sampling module 14 includes a second resistor R2.

[0103] The positive terminal of the first DC voltage source 153 is connected to the anode of the light source module 16, and the negative terminal of the first DC voltage source 153 is connected to the first terminal of the P-type switch M2; the positive terminal of the second DC voltage source 154 is connected to the input terminal of the series voltage reference 11, and the negative terminal of the second DC voltage source 154 is connected to the cathode of the light source module 16, the second terminal of the second resistor R2, and the reference potential terminal of the series voltage reference 11; the positive terminal of the third DC voltage source 155 is connected to the positive terminal of the power supply of the first amplifier A1, and the negative terminal of the third DC voltage source 155 is connected to the negative terminal of the power supply of the first amplifier A1.

[0104] The non-inverting input terminal of the first amplifier A1 is connected to the output terminal of the polarity inversion circuit 121, the input terminal of the polarity inversion circuit 121 is connected to the output terminal of the series voltage reference 11, the inverting input terminal of the first amplifier A1 is connected to the second terminal of the first capacitor C1 and the second terminal of the first resistor R1, and the output terminal of the first amplifier A1 is connected to the first terminal of the first capacitor C1 and the control terminal of the P-type switch M2.

[0105] The first end of the first resistor R1 is connected to the first end of the second resistor R2 and the second end of the P-type switch M2.

[0106] The polarity reversal circuit 121 is used to reverse the polarity of the input voltage and the output voltage (the absolute value remains the same, but the positive and negative values ​​are reversed). The specific structure of the polarity reversal circuit 121 can be found in existing technology and is not specifically limited in this application. In one example, the P-type switch M2 can be a P-type transistor, in which case the first terminal of the P-type switch M2 can be the collector, and the second terminal of the P-type switch M2 can be the emitter. In another example, the P-type switch M1 can be a P-type transistor; in this case, the first terminal of the P-type switch M2 can be the drain, and the second terminal of the P-type switch M2 can be the source.

[0107] The first DC voltage source 153 can be obtained in the same way as the DC voltage source 151 described above. The second DC voltage source 154 and the third DC voltage source 155 can be obtained through isolation power supply derivation. The voltage values ​​of the third DC voltage source 155 and the second DC voltage source 154 can be set according to actual conditions. For example, the voltage value of the second DC voltage source 154 can be 12V, and the voltage value of the third DC voltage source 155 can be 24V. In one example, as shown in Figure 8, the second DC voltage source 154 is a part of the third DC voltage source 155. In other possible embodiments, the second DC voltage source 154 and the third DC voltage source 155 can also be different voltage sources. In one example, if the light source module 16 is a deuterium lamp, the deuterium lamp cathode filament needs to be powered by a DC voltage, which can also be obtained through isolation power supply derivation.

[0108] In one possible implementation, the switching module 13 is an N-type switching transistor M1, the constant current control module 12 is located on the anode side of the light source module 16, and the series-type voltage reference 11 outputs a positive voltage. Referring to Figure 9, the power supply module 15 includes a first DC voltage source 153, a second DC voltage source 154, and a third DC voltage source 155; the constant current control module 12 includes a first amplifier A1, a first resistor R1, and a first capacitor C1; and the sampling module 14 includes a second resistor R2.

[0109] The positive terminal of the first DC voltage source 153 is connected to the first terminal of the N-type switching transistor M1, and the negative terminal of the first DC voltage source 153 is connected to the cathode of the light source module 16. The anode of the light source module 16 is connected to the second terminal of the second resistor R2, the reference potential terminal of the series voltage reference 11, and the negative terminal of the second DC voltage source 154, respectively. The positive terminal of the second DC voltage source 154 is connected to the input terminal of the series voltage reference 11. The positive terminal of the third DC voltage source 155 is connected to the positive terminal of the power supply of the first amplifier A1, and the negative terminal of the third DC voltage source 155 is connected to the negative terminal of the power supply of the first amplifier A1.

[0110] The non-inverting input terminal of the first amplifier A1 is connected to the output terminal of the series voltage reference 11. The inverting input terminal of the first amplifier A1 is connected to the second terminal of the first capacitor C1 and the second terminal of the first resistor R1. The output terminal of the first amplifier A1 is connected to the first terminal of the first capacitor C1 and the control terminal of the N-type switch M1. The first terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the second terminal of the N-type switch M1.

[0111] In one example, the N-type switch M1 can be an N-type transistor, in which case the first terminal of the N-type switch M1 can be the collector, and the second terminal of the N-type switch M1 can be the emitter. In another example, the N-type switch M1 can be an N-type transistor, in which case the first terminal of the N-type switch M1 can be the drain, and the second terminal of the N-type switch M1 can be the source.

[0112] The first DC voltage source 153 can be obtained in the same way as the DC voltage source 151 described above. The second DC voltage source 154 and the third DC voltage source 155 can be obtained through isolation power supply derivation. The voltage values ​​of the third DC voltage source 155 and the second DC voltage source 154 can be configured according to actual conditions; for example, the voltage value of the second DC voltage source 154 can be 12V, and the voltage value of the third DC voltage source 155 can be 24V. In one example, as shown in Figure 9, the second DC voltage source 154 is a part of the third DC voltage source 155. In other possible embodiments, the second DC voltage source 154 and the third DC voltage source 155 can be different voltage sources. In one example, if the light source module 16 is a deuterium lamp, the deuterium lamp cathode filament needs to be powered by a DC voltage, which can also be obtained through isolation power supply derivation.

[0113] In this embodiment, an N-type switching transistor M1 with high driving capability, fast switching speed, and low switching loss is used, which can improve the response speed of the switching module 13 and improve the reliability of the entire light source driving circuit 1.

[0114] In one possible implementation, the switching module 13 is an N-type switching transistor M1, the constant current control module 12 is located on the cathode side of the light source module 16, and the series-type voltage reference 11 outputs a positive voltage. Referring to Figure 10, the power supply module 15 includes a first DC voltage source 153, a second DC voltage source 154, and a third DC voltage source 155; the constant current control module 12 includes a first amplifier A1, a first resistor R1, and a first capacitor C1; and the sampling module 14 includes a second resistor R2.

[0115] The positive terminal of the first DC voltage source 153 is connected to the anode of the light source module 16. The negative terminal of the first DC voltage source 153 is connected to the second terminal of the second resistor R2, the reference potential terminal of the series voltage reference 11, and the negative terminal of the second DC voltage source 154. The positive terminal of the second DC voltage source 154 is connected to the input terminal of the series voltage reference 11. The positive terminal of the third DC voltage source 155 is connected to the positive power supply terminal of the first amplifier A1, and the negative terminal of the third DC voltage source 155 is connected to the negative power supply terminal of the first amplifier A1.

[0116] The non-inverting input of the first amplifier A1 is connected to the output of the series voltage reference 11. The inverting input of the first amplifier A1 is connected to the second terminal of the first capacitor C1 and the second terminal of the first resistor R1. The output of the first amplifier A1 is connected to the first terminal of the first capacitor C1 and the control terminal of the N-type switch M1. The first terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the second terminal of the N-type switch M1. The first terminal of the N-type switch M1 is connected to the cathode of the light source module 16.

[0117] In one example, the N-type switch M1 can be an N-type transistor, in which case the first terminal of the N-type switch M1 can be the collector, and the second terminal of the N-type switch M1 can be the emitter. In another example, the N-type switch M1 can be an N-type transistor, in which case the first terminal of the N-type switch M1 can be the drain, and the second terminal of the N-type switch M1 can be the source.

[0118] The first DC voltage source 153 can be obtained in the same way as the DC voltage source 151 described above. The second DC voltage source 154 and the third DC voltage source 155 can be obtained through isolation power supply derivation. The voltage values ​​of the third DC voltage source 155 and the second DC voltage source 154 can be set according to actual conditions. For example, the voltage value of the second DC voltage source 154 can be 12V, and the voltage value of the third DC voltage source 155 can be 24V. In one example, as shown in Figure 10, the second DC voltage source 154 is a part of the third DC voltage source 155. In other possible embodiments, the second DC voltage source 154 and the third DC voltage source 155 can be different voltage sources. In one example, if the light source module 16 is a deuterium lamp, the deuterium lamp cathode filament needs to be powered by a DC voltage, which can also be obtained through isolation power supply derivation.

[0119] In this embodiment, an N-type switching transistor M1 with high driving capability, fast switching speed, and low switching loss is used, which can improve the response speed of the switching module 13 and improve the reliability of the entire light source driving circuit 1.

[0120] In one possible implementation, the switching module 13 is a P-type switching transistor M2, the constant current control module 12 is located on the anode side of the light source module 16, and the series-type voltage reference 11 outputs a negative voltage. Referring to Figure 11, the power supply module 15 includes a first DC voltage source 153, a second DC voltage source 154, and a third DC voltage source 155; the constant current control module 12 includes a first amplifier A1, a first resistor R1, and a first capacitor C1; and the sampling module 14 includes a second resistor R2.

[0121] The positive terminal of the first DC voltage source 153 is connected to the second terminal of the second resistor R2, the reference potential terminal of the series voltage reference 11, and the positive terminal of the second DC voltage source 154. The negative terminal of the first DC voltage source 153 is connected to the cathode of the light source module 16. The anode of the light source module 16 is connected to the first terminal of the P-type switch M2. The negative terminal of the second DC voltage source 154 is connected to the input terminal of the series voltage reference 11. The positive terminal of the third DC voltage source 155 is connected to the positive terminal of the power supply of the first amplifier A1, and the negative terminal of the third DC voltage source 155 is connected to the negative terminal of the power supply of the first amplifier A1.

[0122] The non-inverting input of the first amplifier A1 is connected to the output of the series voltage reference 11. The inverting input of the first amplifier A1 is connected to the second terminal of the first capacitor C1 and the second terminal of the first resistor R1. The output of the first amplifier A1 is connected to the first terminal of the first capacitor C1 and the control terminal of the P-type switch M2. The first terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the second terminal of the P-type switch M2. In one example, the second DC voltage source 154 is a part of the third DC voltage source 155. In other possible embodiments, the second DC voltage source 154 and the third DC voltage source 155 can be different voltage sources.

[0123] In one possible implementation, the switching module 13 is a P-type switching transistor M2, the constant current control module 12 is located on the cathode side of the light source module 16, and the series-type voltage reference 11 outputs a negative voltage. Referring to Figure 12, the power supply module 15 includes a first DC voltage source 153, a second DC voltage source 154, and a third DC voltage source 155; the constant current control module 12 includes a first amplifier A1, a first resistor R1, and a first capacitor C1; and the sampling module 14 includes a second resistor R2.

[0124] The positive terminal of the first DC voltage source 153 is connected to the anode of the light source module 16, and the negative terminal of the first DC voltage source 153 is connected to the first terminal of the P-type switch M2; the negative terminal of the second DC voltage source 154 is connected to the input terminal of the series voltage reference 11, and the positive terminal of the second DC voltage source 154 is connected to the cathode of the light source module 16, the second terminal of the second resistor R2, and the reference potential terminal of the series voltage reference 11; the positive terminal of the third DC voltage source 155 is connected to the positive terminal of the power supply of the first amplifier A1, and the negative terminal of the third DC voltage source 155 is connected to the negative terminal of the power supply of the first amplifier A1.

[0125] The non-inverting input of the first amplifier A1 is connected to the output of the series voltage reference 11. The inverting input of the first amplifier A1 is connected to the second terminal of the first capacitor C1 and the second terminal of the first resistor R1. The output of the first amplifier A1 is connected to the first terminal of the first capacitor C1 and the control terminal of the P-type switch M2. The first terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the second terminal of the P-type switch M2. In one example, the second DC voltage source 154 is a part of the third DC voltage source 155. In other possible embodiments, the second DC voltage source 154 and the third DC voltage source 155 can be different voltage sources.

[0126] In one possible implementation, the switching module 13 is a P-type switching transistor M2, the constant current control module 12 is located on the anode side of the light source module 16, and the series voltage reference 11 outputs a positive voltage. Referring to Figure 13, the power supply module 15 includes a first DC voltage source 153, a second DC voltage source 154, and a third DC voltage source 155; the constant current control module 12 includes a first amplifier A1, a first resistor R1, a first capacitor C1, and a polarity reversal circuit 121; the sampling module 14 includes a second resistor R2.

[0127] The positive terminal of the first DC voltage source 153 is connected to the second terminal of the second resistor R2, the reference potential terminal of the series voltage reference 11, and the negative terminal of the second DC voltage source 154, respectively. The negative terminal of the first DC voltage source 153 is connected to the cathode of the light source module 16. The anode of the light source module 16 is connected to the first terminal of the P-type switch M2.

[0128] The positive terminal of the second DC voltage source 154 is connected to the input terminal of the series voltage reference 11; the positive terminal of the third DC voltage source 155 is connected to the positive power supply terminal of the first amplifier A1, and the negative terminal of the third DC voltage source 155 is connected to the negative power supply terminal of the first amplifier A1.

[0129] The non-inverting input of the first amplifier A1 is connected to the output of the polarity inversion circuit 121, and the input of the polarity inversion circuit 121 is connected to the output of the series voltage reference 11. The inverting input of the first amplifier A1 is connected to the second terminal of the first capacitor C1 and the second terminal of the first resistor R1, respectively. The output of the first amplifier A1 is connected to the first terminal of the first capacitor C1 and the control terminal of the P-type switch M2, respectively. The first terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the second terminal of the P-type switch M2, respectively. In one example, the second DC voltage source 154 is a part of the third DC voltage source 155. In other possible embodiments, the second DC voltage source 154 and the third DC voltage source 155 can be different voltage sources.

[0130] In one possible implementation, the switching module 13 is an N-type switching transistor M1, the constant current control module 12 is located on the cathode side of the light source module 16, and the series-type voltage reference 11 outputs a negative voltage. Referring to Figure 14, the power supply module 15 includes a first DC voltage source 153, a second DC voltage source 154, and a third DC voltage source 155; the constant current control module 12 includes a first amplifier A1, a first resistor R1, a first capacitor C1, and a polarity reversal circuit 121; the sampling module 14 includes a second resistor R2.

[0131] The positive terminal of the first DC voltage source 153 is connected to the anode of the light source module 16, and the negative terminal of the first DC voltage source 153 is connected to the second terminal of the second resistor R2, the reference potential terminal of the series voltage reference 11, and the positive terminal of the second DC voltage source 154, respectively; the cathode of the light source module 16 is connected to the first terminal of the N-type switch M1.

[0132] The negative terminal of the second DC voltage source 154 is connected to the input terminal of the series voltage reference 11; the positive terminal of the third DC voltage source 155 is connected to the positive power supply terminal of the first amplifier A1, and the negative terminal of the third DC voltage source 155 is connected to the negative power supply terminal of the first amplifier A1.

[0133] The non-inverting input of the first amplifier A1 is connected to the output of the polarity inversion circuit 121, and the input of the polarity inversion circuit 121 is connected to the output of the series voltage reference 11. The inverting input of the first amplifier A1 is connected to the second terminal of the first capacitor C1 and the second terminal of the first resistor R1, respectively. The output of the first amplifier A1 is connected to the first terminal of the first capacitor C1 and the control terminal of the N-type switch M1, respectively. The first terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the second terminal of the N-type switch M1, respectively. In one example, the second DC voltage source 154 is a part of the third DC voltage source 155. In other possible embodiments, the second DC voltage source 154 and the third DC voltage source 155 can be different voltage sources.

[0134] In one possible implementation, the switching module 13 is an N-type switching transistor M1, the constant current control module 12 is located on the anode side of the light source module 16, and the series-type voltage reference 11 outputs a negative voltage. Referring to Figure 15, the power supply module 15 includes a first DC voltage source 153, a second DC voltage source 154, and a third DC voltage source 155; the constant current control module 12 includes a first amplifier A1, a first resistor R1, a first capacitor C1, and a polarity reversal circuit 121; the sampling module 14 includes a second resistor R2.

[0135] The positive terminal of the first DC voltage source 153 is connected to the first terminal of the N-type switching transistor M1, and the negative terminal of the first DC voltage source 153 is connected to the cathode of the light source module 16; the anode of the light source module 16 is connected to the second terminal of the second resistor R2, the reference potential terminal of the series voltage reference 11, and the positive terminal of the second DC voltage source 154; the negative terminal of the second DC voltage source 154 is connected to the input terminal of the series voltage reference 11; the positive terminal of the third DC voltage source 155 is connected to the positive power supply terminal of the first amplifier A1, and the negative terminal of the third DC voltage source 155 is connected to the negative power supply terminal of the first amplifier A1;

[0136] The non-inverting input of the first amplifier A1 is connected to the output of the polarity inversion circuit 121, and the input of the polarity inversion circuit 121 is connected to the output of the series voltage reference 11. The inverting input of the first amplifier A1 is connected to the second terminal of the first capacitor C1 and the second terminal of the first resistor R1, respectively. The output of the first amplifier A1 is connected to the first terminal of the first capacitor C1 and the control terminal of the N-type switch M1, respectively. The first terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the second terminal of the N-type switch M1, respectively. In one example, the second DC voltage source 154 is a part of the third DC voltage source 155. In other possible embodiments, the second DC voltage source 154 and the third DC voltage source 155 can be different voltage sources.

[0137] This application also provides a light source system 2, as shown in FIG6, the light source system 2 including any of the light source driving circuits 1 described in the above embodiments.

[0138] It should be noted that, in this document, relational terms such as "first" and "second" are used only 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 one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0139] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0140] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A light source driving circuit, the circuit comprising: Series-type voltage reference, constant current control module, switching module, sampling module, power supply module and light source module; The input terminal of the series voltage reference is connected to the power supply module, the output terminal of the series voltage reference is connected to the constant current control module, and the reference potential terminal of the series voltage reference is connected to the sampling module; the constant current control module is also connected to the sampling module, the switching module, and the power supply module respectively; the switching module, the sampling module, and the light source module are connected in series, and any one of the switching module, the sampling module, and the light source module is connected to the power supply module; The series-type voltage reference is used to output a preset reference voltage signal to the constant current control module; The sampling module is used to convert the operating current of the light source module into a first voltage signal and transmit the first voltage signal to the constant current control module; The constant current control module is used to compare the first voltage signal with the reference voltage signal. If the voltage difference between the first voltage signal and the reference voltage signal is greater than a preset threshold, the module adjusts its own output second voltage signal so that the switching module adjusts its conduction level based on the second voltage signal until the voltage difference between the first voltage signal and the reference voltage signal is not greater than the preset threshold.

2. The circuit according to claim 1, wherein, The output terminal of the series voltage reference is connected to the first input terminal of the constant current control module, and the reference potential terminal of the series voltage reference is connected to the second terminal of the sampling module and the light source module, respectively. The second input terminal of the constant current control module is connected to the first terminal of the sampling module and the second terminal of the switching module, respectively. The output terminal of the constant current control module is connected to the control terminal of the switching module, and the first terminal of the switching module is connected to the power supply module. The positive terminal of the power supply of the constant current control module is connected to the power supply module.

3. The circuit according to claim 2, wherein, The power module includes a DC voltage source and an isolated power supply; The positive input terminal of the isolation power supply is connected to the power supply terminal, and the positive output terminal of the isolation power supply is connected to the positive power supply terminal of the constant current control module and the input terminal of the series voltage reference, respectively. The DC voltage source is connected to the first terminal of the switching module and the power supply terminal, respectively. The isolation power supply is used to supply power to the constant current control module and the series voltage reference respectively; The DC voltage source is used to power the light source module.

4. The circuit according to claim 2, wherein, The power module includes a DC voltage source; The DC voltage source is connected to the first terminal of the switching module, the positive power terminal of the constant current control module, the input terminal of the series voltage reference, and the power supply terminal, respectively. The DC voltage source is used to supply power to the constant current control module, the series voltage reference, and the light source module, respectively.

5. The circuit according to claim 2, wherein, The constant current control module includes a first amplifier, a first resistor, and a first capacitor; The non-inverting input terminal of the first amplifier is connected to the output terminal of the series voltage reference, the inverting input terminal of the first amplifier is connected to the second terminal of the first capacitor and the second terminal of the first resistor, the output terminal of the first amplifier is connected to the first terminal of the first capacitor and the control terminal of the switching module, and the positive terminal of the power supply of the first amplifier is connected to the power supply module. The first end of the first resistor is connected to the first end of the sampling module and the second end of the switching module.

6. The circuit according to claim 2, wherein, The sampling module includes a second resistor; The first end of the second resistor is connected to the second end of the switch module and the second input end of the constant current control module, respectively, and the second end of the second resistor is connected to the reference potential end of the light source module and the series voltage reference.

7. The circuit according to claim 2, wherein, The switching module includes an N-type switching transistor; The control terminal of the N-type switching transistor is connected to the output terminal of the constant current control module, the first terminal of the N-type switching transistor is connected to the power supply module, and the second terminal of the N-type switching transistor is connected to the second input terminal of the constant current control module and the first terminal of the sampling module, respectively.

8. The circuit according to claim 5, wherein, The negative terminal of the power supply of the first amplifier is connected to the reference potential terminal of the series voltage reference, the second terminal of the sampling module, and the light source module, respectively.

9. The circuit according to claim 3, wherein, The negative input terminal of the isolation power supply is grounded; the negative output terminal of the isolation power supply is connected to the reference potential terminal of the series voltage reference, the second terminal of the sampling module, and the light source module, respectively.

10. The circuit according to claim 3 or 4, wherein, The power supply mode of the power supply terminal is DC power supply mode.

11. The circuit according to claim 2, wherein, The power supply module includes a first DC voltage source, a second DC voltage source, and a third DC voltage source; the series-type voltage reference outputs a positive voltage; the switching module is a P-type switching transistor; the constant current control module includes a first amplifier, a first resistor, a first capacitor, and a polarity reversal circuit; and the sampling module includes a second resistor. The positive terminal of the first DC voltage source is connected to the anode of the light source module, and the negative terminal of the first DC voltage source is connected to the first terminal of the P-type switching transistor; the positive terminal of the second DC voltage source is connected to the input terminal of the series voltage reference, and the negative terminal of the second DC voltage source is connected to the cathode of the light source module, the second terminal of the second resistor, and the reference potential terminal of the series voltage reference; the positive terminal of the third DC voltage source is connected to the positive power supply terminal of the first amplifier, and the negative terminal of the third DC voltage source is connected to the negative power supply terminal of the first amplifier. The non-inverting input terminal of the first amplifier is connected to the output terminal of the polarity inversion circuit, the input terminal of the polarity inversion circuit is connected to the output terminal of the series voltage reference, the inverting input terminal of the first amplifier is connected to the second terminal of the first capacitor and the second terminal of the first resistor, and the output terminal of the first amplifier is connected to the first terminal of the first capacitor and the control terminal of the P-type switch. The first end of the first resistor is connected to the first end of the second resistor and the second end of the P-type switch.

12. The circuit according to claim 2, wherein, The switching module is an N-type switching transistor, the series voltage reference outputs a positive voltage, the power supply module includes a first DC voltage source, a second DC voltage source, and a third DC voltage source; the constant current control module includes a first amplifier, a first resistor, and a first capacitor, and the sampling module includes a second resistor; The positive terminal of the first DC voltage source is connected to the first terminal of the N-type switching transistor, and the negative terminal of the first DC voltage source is connected to the cathode of the light source module. The anode of the light source module is connected to the second terminal of the second resistor, the reference potential terminal of the series voltage reference, and the negative terminal of the second DC voltage source. The positive terminal of the second DC voltage source is connected to the input terminal of the series voltage reference. The positive terminal of the third DC voltage source is connected to the positive terminal of the power supply of the first amplifier, and the negative terminal of the third DC voltage source is connected to the negative terminal of the power supply of the first amplifier. The non-inverting input of the first amplifier is connected to the output of the series voltage reference, the inverting input of the first amplifier is connected to the second terminal of the first capacitor and the second terminal of the first resistor, the output of the first amplifier is connected to the first terminal of the first capacitor and the control terminal of the N-type switch, and the first terminal of the first resistor is connected to the first terminal of the second resistor and the second terminal of the N-type switch.

13. The circuit according to claim 2, wherein, The switching module is a P-type switching transistor, the series voltage reference outputs a negative voltage, the power supply module includes a first DC voltage source, a second DC voltage source, and a third DC voltage source; the constant current control module includes a first amplifier, a first resistor, and a first capacitor, and the sampling module includes a second resistor; The positive terminal of the first DC voltage source is connected to the anode of the light source module, and the negative terminal of the first DC voltage source is connected to the first terminal of the P-type switch. The negative terminal of the second DC voltage source is connected to the input terminal of the series voltage reference, and the positive terminal of the second DC voltage source is connected to the cathode of the light source module, the second terminal of the second resistor, and the reference potential terminal of the series voltage reference. The positive terminal of the third DC voltage source is connected to the positive terminal of the power supply of the first amplifier, and the negative terminal of the third DC voltage source is connected to the negative terminal of the power supply of the first amplifier. The non-inverting input of the first amplifier is connected to the output of the series voltage reference, the inverting input of the first amplifier is connected to the second terminal of the first capacitor and the second terminal of the first resistor, the output of the first amplifier is connected to the first terminal of the first capacitor and the control terminal of the P-type switch, and the first terminal of the first resistor is connected to the first terminal of the second resistor and the second terminal of the P-type switch.

14. The circuit according to claim 2, wherein, The switching module is an N-type switching transistor, the series voltage reference outputs a negative voltage, the power supply module includes a first DC voltage source, a second DC voltage source, and a third DC voltage source; the constant current control module includes a first amplifier, a first resistor, a first capacitor, and a polarity reversal circuit, and the sampling module includes a second resistor; The positive terminal of the first DC voltage source is connected to the first terminal of the N-type switching transistor, and the negative terminal of the first DC voltage source is connected to the cathode of the light source module; the anode of the light source module is connected to the second terminal of the second resistor, the reference potential terminal of the series voltage reference, and the positive terminal of the second DC voltage source; the negative terminal of the second DC voltage source is connected to the input terminal of the series voltage reference; the positive terminal of the third DC voltage source is connected to the positive terminal of the power supply of the first amplifier, and the negative terminal of the third DC voltage source is connected to the negative terminal of the power supply of the first amplifier; The non-inverting input of the first amplifier is connected to the output of the polarity inversion circuit, the input of the polarity inversion circuit is connected to the output of the series voltage reference, the inverting input of the first amplifier is connected to the second terminal of the first capacitor and the second terminal of the first resistor, the output of the first amplifier is connected to the first terminal of the first capacitor and the control terminal of the N-type switch, and the first terminal of the first resistor is connected to the first terminal of the second resistor and the second terminal of the N-type switch.

15. The circuit according to claim 1, wherein, The output terminal of the series voltage reference is connected to the first input terminal of the constant current control module, and the reference potential terminal of the series voltage reference is connected to the second terminal of the sampling module and the power supply module, respectively. The second input terminal of the constant current control module is connected to the first terminal of the sampling module and the second terminal of the switching module, respectively. The output terminal of the constant current control module is connected to the control terminal of the switching module, the first terminal of the switching module is connected to the light source module, and the positive and negative terminals of the power supply of the constant current control module are connected to the power supply module, respectively.

16. The circuit according to claim 15, wherein, The power supply module includes a first DC voltage source, a second DC voltage source, and a third DC voltage source; the switching module is an N-type switching transistor, and the series-type voltage reference outputs a positive voltage; the constant current control module includes a first amplifier, a first resistor, and a first capacitor, and the sampling module includes a second resistor; The positive terminal of the first DC voltage source is connected to the anode of the light source module, and the negative terminal of the first DC voltage source is connected to the second terminal of the second resistor, the reference potential terminal of the series voltage reference, and the negative terminal of the second DC voltage source, respectively; the positive terminal of the second DC voltage source is connected to the input terminal of the series voltage reference; the positive terminal of the third DC voltage source is connected to the positive terminal of the power supply of the first amplifier, and the negative terminal of the third DC voltage source is connected to the negative terminal of the power supply of the first amplifier; The non-inverting input of the first amplifier is connected to the output of the series voltage reference. The inverting input of the first amplifier is connected to the second terminal of the first capacitor and the second terminal of the first resistor. The output of the first amplifier is connected to the first terminal of the first capacitor and the control terminal of the N-type switch. The first terminal of the first resistor is connected to the first terminal of the second resistor and the second terminal of the N-type switch. The first terminal of the N-type switch is connected to the cathode of the light source module.

17. The circuit according to claim 15, wherein, The switching module is a P-type switching transistor, the series voltage reference outputs a negative voltage, the power supply module includes a first DC voltage source, a second DC voltage source, and a third DC voltage source; the constant current control module includes a first amplifier, a first resistor, and a first capacitor, and the sampling module includes a second resistor; The positive terminal of the first DC voltage source is connected to the second terminal of the second resistor, the reference potential terminal of the series voltage reference, and the positive terminal of the second DC voltage source. The negative terminal of the first DC voltage source is connected to the cathode of the light source module. The anode of the light source module is connected to the first terminal of the P-type switch. The negative terminal of the second DC voltage source is connected to the input terminal of the series voltage reference. The positive terminal of the third DC voltage source is connected to the positive terminal of the power supply of the first amplifier, and the negative terminal of the third DC voltage source is connected to the negative terminal of the power supply of the first amplifier. The non-inverting input of the first amplifier is connected to the output of the series voltage reference, the inverting input of the first amplifier is connected to the second terminal of the first capacitor and the second terminal of the first resistor, the output of the first amplifier is connected to the first terminal of the first capacitor and the control terminal of the P-type switch, and the first terminal of the first resistor is connected to the first terminal of the second resistor and the second terminal of the P-type switch.

18. The circuit according to claim 15, wherein, The switching module is a P-type switching transistor, and the series-type voltage reference outputs a positive voltage. The power supply module includes a first DC voltage source, a second DC voltage source, and a third DC voltage source. The constant current control module includes a first amplifier, a first resistor, a first capacitor, and a polarity reversal circuit. The sampling module includes a second resistor. The positive terminal of the first DC voltage source is connected to the second terminal of the second resistor, the reference potential terminal of the series voltage reference, and the negative terminal of the second DC voltage source, respectively. The negative terminal of the first DC voltage source is connected to the cathode of the light source module. The anode of the light source module is connected to the first terminal of the P-type switch. The positive terminal of the second DC voltage source is connected to the input terminal of the series voltage reference; the positive terminal of the third DC voltage source is connected to the positive power supply terminal of the first amplifier, and the negative terminal of the third DC voltage source is connected to the negative power supply terminal of the first amplifier. The non-inverting input of the first amplifier is connected to the output of the polarity inversion circuit, the input of the polarity inversion circuit is connected to the output of the series voltage reference, the inverting input of the first amplifier is connected to the second terminal of the first capacitor and the second terminal of the first resistor, the output of the first amplifier is connected to the first terminal of the first capacitor and the control terminal of the P-type switch, and the first terminal of the first resistor is connected to the first terminal of the second resistor and the second terminal of the P-type switch.

19. The circuit according to claim 15, wherein, The switching module is an N-type switching transistor, the series voltage reference outputs a negative voltage, the power supply module includes a first DC voltage source, a second DC voltage source, and a third DC voltage source; the constant current control module includes a first amplifier, a first resistor, a first capacitor, and a polarity reversal circuit, and the sampling module includes a second resistor; The positive terminal of the first DC voltage source is connected to the anode of the light source module, and the negative terminal of the first DC voltage source is connected to the second terminal of the second resistor, the reference potential terminal of the series voltage reference, and the positive terminal of the second DC voltage source; the cathode of the light source module is connected to the first terminal of the N-type switching transistor. The negative terminal of the second DC voltage source is connected to the input terminal of the series voltage reference; the positive terminal of the third DC voltage source is connected to the positive power supply terminal of the first amplifier, and the negative terminal of the third DC voltage source is connected to the negative power supply terminal of the first amplifier. The non-inverting input of the first amplifier is connected to the output of the polarity inversion circuit, the input of the polarity inversion circuit is connected to the output of the series voltage reference, the inverting input of the first amplifier is connected to the second terminal of the first capacitor and the second terminal of the first resistor, the output of the first amplifier is connected to the first terminal of the first capacitor and the control terminal of the N-type switch, and the first terminal of the first resistor is connected to the first terminal of the second resistor and the second terminal of the N-type switch.

20. A light source system, the light source system comprising the light source driving circuit according to any one of claims 1-19.

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