Light source driving circuit and light source system

Abstract

The embodiment of the invention provides a light source driving circuit and a light source system. The light source driving 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, 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 the working current of the light source module into a first voltage signal and transmitting the first voltage signal to the constant current control module; the constant-current control module is used for comparing the first voltage signal with a reference voltage signal, and adjusting a second voltage signal output by the constant-current control module when the voltage difference value between the first voltage signal and the reference voltage signal is greater than a preset threshold value, so that the switch module adjusts the conduction degree of the constant-current control module based on the second voltage signal; the voltage difference value between the first voltage signal and the reference voltage signal is not greater than the preset threshold value.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a light source driving circuit and a light source system. Background Art

[0002] In the current detection and analysis instrument system, the following are usually used: Figure 1 The circuit structure shown drives 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.

[0003] Figure 1 The deuterium lamp driving circuit shown includes a deuterium lamp, a voltage source, a reference voltage source, a constant current control module, a sampling resistor, and a switching tube. The voltage source is used to generate a suitable DC voltage to provide power for the anode of the deuterium lamp. The sampling resistor is used to convert the current flowing through the deuterium lamp into a sampling voltage. The reference voltage source is used to provide a stable reference voltage for the constant current control module, and the reference voltage is a given value of the current flowing through the deuterium lamp. The constant current control module is used to output a control signal to act on the switching tube based on the sampling voltage and the reference voltage. The switching tube is used to adjust the current flowing through the deuterium lamp based on the output of the constant current control module.

[0004] but Figure 1 In the deuterium lamp driving circuit shown, a parallel-regulated voltage reference is used as a reference voltage source. The parallel-regulated voltage reference has poor stability, which may lead to poor stability of the deuterium lamp driving circuit, and the brightness of the light source cannot be kept stable after the deuterium lamp is lit. Summary of the invention

[0005] The purpose of the embodiments of the present 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:

[0006] In a first aspect, an embodiment of the present application provides a light source driving circuit, the circuit comprising:

[0007] Series voltage reference, constant current control module, switch module, sampling module, power module and light source module;

[0008] The input end of the series voltage reference is connected to the power module, the output end of the series voltage reference is connected to the constant current control module, and the reference potential end of the series voltage reference is connected to the sampling module; the constant current control module is also connected to the sampling module, the switch module, and the power module respectively; the switch module, the sampling module, and the light source module are connected in series, and any one of the switch module, the sampling module, and the light source module is connected to the power module;

[0009] The series voltage reference is used to output a preset reference voltage signal to the constant current control module;

[0010] The sampling module is used to convert the working current of the light source module into a first voltage signal, and transmit the first voltage signal to the constant current control module;

[0011] The constant current control module is used to compare the first voltage signal with the reference voltage signal, and when the voltage difference between the first voltage signal and the reference voltage signal is greater than a preset threshold, adjust the second voltage signal output by itself, so that the switch module 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 no greater than the preset threshold.

[0012] In a possible implementation, the output end of the series voltage reference is connected to the first input end of the constant current control module, and the reference potential end of the series voltage reference is respectively connected to the second end of the sampling module and the light source module; the second input end of the constant current control module is respectively connected to the first end of the sampling module and the second end of the switch module, the output end of the constant current control module is connected to the control end of the switch module, and the first end of the switch module is connected to the power supply module; the positive power supply end of the constant current control module is connected to the power supply module.

[0013] In a possible implementation, the power supply module includes a DC voltage source and an isolated power supply;

[0014] 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 respectively connected to the positive power supply terminal of the constant current control module and the input terminal of the series voltage reference;

[0015] The DC voltage source is connected to the first end of the switch module and the power supply end respectively;

[0016] The isolated power supply is used to supply power to the constant current control module and the series voltage reference respectively;

[0017] The DC voltage source is used to supply power to the light source module.

[0018] In a possible implementation, the power supply module includes a DC voltage source;

[0019] The DC voltage source is respectively connected to the first end of the switch module, the positive power supply end of the constant current control module, the input end of the series voltage reference, and the power supply end;

[0020] 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.

[0021] In a possible implementation, the constant current control module includes a first amplifier, a first resistor, and a first capacitor;

[0022] 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 respectively 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 respectively connected to the first terminal of the first capacitor and the control terminal of the switch module, and the positive power supply terminal of the first amplifier is connected to the power supply module;

[0023] The first end of the first resistor is connected to the first end of the sampling module and the second end of the switch module respectively.

[0024] In a possible implementation, the sampling module includes a second resistor;

[0025] 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 light source module and the reference potential end of the series voltage reference respectively.

[0026] In a possible implementation manner, the switch module includes an N-type switch tube;

[0027] The control end of the N-type switch tube is connected to the output end of the constant current control module, the first end of the N-type switch tube is connected to the power module, and the second end of the N-type switch tube is respectively connected to the second input end of the constant current control module and the first end of the sampling module.

[0028] In a possible implementation manner, the negative power supply terminal of the first amplifier is respectively connected to the reference potential terminal of the series voltage reference, the second terminal of the sampling module, and the light source module.

[0029] In a possible implementation, the negative input terminal of the isolated power supply is grounded; the negative output terminal of the isolated power supply is respectively connected to the reference potential terminal of the series voltage reference, the second terminal of the sampling module, and the light source module.

[0030] In a possible implementation manner, the power supply mode of the power supply end is a direct current power supply mode.

[0031] In a second aspect, an embodiment of the present application provides a light source system, which includes the light source driving circuit described in any one of the above-mentioned first aspect.

[0032] Beneficial effects of the embodiments of the present application:

[0033] The embodiment of the present application provides a light source driving circuit and a light source system, wherein the light source driving 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; the input end of the series voltage reference is connected to the power supply module, the output end of the series voltage reference is connected to the constant current control module, and the reference potential end of the series voltage reference is connected to the sampling module; the constant current control module is also connected to the sampling module, the switch module and the power supply module respectively; the switch module, the sampling module and the light source module are connected in series, and any one of the switch 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 working 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, and when the voltage difference between the first voltage signal and the reference voltage signal is greater than a preset threshold, adjust the second voltage signal outputted by itself, so that the switch module 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. By using a series voltage reference as a reference voltage source (the stability of the series voltage reference is higher than that of the parallel voltage reference), connecting the input end of the series voltage reference to a power module, connecting the output end of the series voltage reference to a constant current control module, and connecting the reference potential end of the series voltage reference to a sampling module, the stability of the light source driving circuit is improved, so that the brightness of the light source remains highly stable.

[0034] Of course, implementing any product or method of the present application does not necessarily require achieving all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0036] Figure 1 A structural schematic diagram of a deuterium lamp driving circuit in the related art;

[0037] Figure 2 A first structural schematic diagram of a light source driving circuit provided in an embodiment of the present application;

[0038] Figure 3 A second structural schematic diagram of a light source driving circuit provided in an embodiment of the present application;

[0039] Figure 4A third structural schematic diagram of the light source driving circuit provided in an embodiment of the present application;

[0040] Figure 5 A fourth structural schematic diagram of the light source driving circuit provided in an embodiment of the present application;

[0041] Figure 6 A schematic diagram of the structure of a light source system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field based on the present application belong to the scope of protection of the present application.

[0043] In the current detection and analysis instrument system, the following are usually used: Figure 1 The circuit structure shown drives 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.

[0044] Figure 1 The deuterium lamp driving circuit shown includes a deuterium lamp, a voltage source, a reference voltage source, a constant current control module, a sampling resistor, and a switching tube. The voltage source is used to generate a suitable DC voltage to provide power for the anode of the deuterium lamp. The sampling resistor is used to convert the current flowing through the deuterium lamp into a sampling voltage. The reference voltage source is used to provide a stable reference voltage for the constant current control module, and the reference voltage is a given value of the current flowing through the deuterium lamp. The constant current control module is used to output a control signal to act on the switching tube based on the sampling voltage and the reference voltage. The switching tube is used to adjust the current flowing through the deuterium lamp based on the output of the constant current control module.

[0045] Among them, when the deuterium lamp is lit normally, the current flows out from the higher potential end of the voltage source, flows through the sampling resistor and the switching tube and enters the anode of the deuterium lamp; the power supply provides direct current, and the negative power 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 (ground GND); the power supply for the reference voltage source and the constant current control module is provided by the voltage source through 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.

[0046] but Figure 1In the deuterium lamp driving circuit shown, a parallel-regulated voltage reference is used as a reference voltage source (there are two ports, a positive terminal and a negative terminal, the positive terminal is respectively connected to the voltage source and the sampling resistor, and the negative terminal is respectively connected to the constant current control module and the ground). The parallel-regulated voltage reference has poor stability, which may lead to poor stability of the deuterium lamp driving circuit, and the brightness of the light source cannot be kept stable after the deuterium lamp is lit.

[0047] also, Figure 1 In the deuterium lamp driving circuit shown, the reference voltage source, the constant current control module and the deuterium lamp are all powered by a voltage source. The power supply current loop of the reference voltage source and the constant current control module is likely to affect the stability of the anode current of the deuterium lamp.

[0048] The switch tube can only use a P-type switch tube (such as a PNP transistor, a P-type field effect transistor PMOS tube, etc.) with poor performance and is difficult to obtain, which affects the overall performance of the deuterium lamp drive circuit.

[0049] In order to improve at least one of the above problems, an embodiment of the present application provides a light source driving circuit and a light source system.

[0050] Next, the light source driving circuit 1 provided in the embodiment of the present application is described in detail. Figure 2 , is a first structural diagram of a light source driving circuit 1 provided in an embodiment of the present application, the light source driving circuit 1 comprises:

[0051] A series voltage reference 11, a constant current control module 12, a switch module 13, a sampling module 14, a power module 15 and a light source module 16;

[0052] The input end of the series voltage reference 11 is connected to the power module 15, the output end of the series voltage reference 11 is connected to the first input end of the constant current control module 12, and the reference potential end of the series voltage reference 11 is respectively connected to the second end of the sampling module 14 and the light source module 16; the second input end of the constant current control module 12 is respectively connected to the first end of the sampling module 14 and the second end of the switch module 13, the output end of the constant current control module 12 is connected to the control end of the switch module 13, and the first end of the switch module 13 is connected to the power module 15; the positive power supply end of the constant current control module 12 is connected to the power module 15;

[0053] 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;

[0054] The sampling module 14 is used to convert the working 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;

[0055] The constant current control module 12 is used to compare the first voltage signal with the reference voltage signal, and when the voltage difference between the first voltage signal and the reference voltage signal is greater than a preset threshold, adjust the second voltage signal at its own output end so that the switch 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 no greater than the preset threshold.

[0056] The sampling module 14 converts the working current of the light source module 16 into a voltage signal to realize the feedback of the actual working current of the light source module 16. The sampling module 14 can be a sampling resistor or other types of current sampling devices, which are not specifically limited in the present application.

[0057] The series voltage reference 11 is used to output a highly stable preset reference voltage signal, and the preset reference voltage signal provides an accurate current setting reference (constant current reference value) for the constant current control module 12 .

[0058] The constant current control module 12 compares the sampled voltage signal (the first voltage signal, that is, the voltage drop of the sampling module 14) of the sampling module 14 with the reference voltage signal, and dynamically adjusts the conduction degree of the switch module 13 based on the voltage difference between the two, so that the working current of the light source module 16 tends to a certain value, that is, maintains a constant current.

[0059] In an example, if the voltage value of the reference voltage signal is 1.2V and the resistance value of the sampling resistor is 4Ω, the current value of the constant current can be calculated to be 300mA.

[0060] The preset threshold value can be set according to the actual situation of the circuit. In one example, the preset threshold value can be 0.05V.

[0061] In one example, the preset threshold value may be 0V. When the preset threshold value is 0V, the constant current control module 12 is used to compare the first voltage signal with the reference voltage signal. When the voltage value of the first voltage signal is not equal to the voltage value of the reference voltage signal, the constant current control module 12 adjusts the second voltage signal at its output end so that the switch module 13 adjusts its conduction degree 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, when the first voltage signal is greater than the reference voltage signal, the constant current control module 12 adjusts the second voltage signal at its output end to decrease, the conduction degree of the switch module 13 is reduced, and the working current of the light source module 16 is reduced 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 constant current control module 12 adjusts the second voltage signal at its output end to increase, the conduction degree of the switch module 13 is increased, and the working current of the light source module 16 is increased until the voltage value of the first voltage signal is equal to the voltage value of the reference voltage signal.

[0062] The series voltage reference 11 mainly includes the following units: 1. A reference voltage source, which usually adopts a bandgap reference structure or a Zener diode to provide a high-stability reference voltage; 2. A comparison amplifier, which compares the sampled voltage with the reference voltage, and outputs a control signal to control the voltage adjustment unit based on the difference between the sampled voltage and the reference voltage; 3. A voltage adjustment unit, which is composed of a power transistor or a field effect transistor, and dynamically adjusts its own voltage drop according to the control signal to maintain the voltage stability at the output end of the series voltage reference 11; 4. A sampling circuit, which usually adopts a voltage divider network composed of a resistor or a potentiometer to proportionally feed back the voltage at the output end of the series voltage reference 11 to the comparison amplifier.

[0063] The series voltage reference 11 includes three ports, namely, an input terminal, an output terminal, and a reference potential terminal. The input terminal is used to connect to the power module 15 to provide a working voltage for the series voltage reference 11; the output terminal is used to output a high-precision, high-stability preset reference voltage signal; the reference potential terminal is used to provide a reference potential to ensure that the voltages of the input and output terminals are based on a common reference point and form a complete current loop.

[0064] Compared with the parallel regulated voltage reference, the series voltage reference 11 has higher accuracy and stability, and 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 remains highly accurate and highly stable.

[0065] The reference potential end of the series voltage reference 11 is connected to the second end of the sampling module 14, that is, the reference potential end of the series voltage reference 11 and the second end of the sampling module 14 maintain the same potential (one end of the light source module 16), which brings the following beneficial effects: the measurement of the reference voltage signal and the sampling voltage signal (first voltage signal) are both based on the same potential, which can ensure that the voltage difference between the reference voltage signal and the sampling voltage signal input by 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 the need to additionally compensate for the influence of the potential difference on the comparison result, thereby simplifying the control logic.

[0066] Figure 2 In the light source driving circuit 1 shown, the power module 15 supplies power (provides power) to the series voltage reference 11 , the light source module 16 , and the constant current control module 12 , respectively.

[0067] In the embodiment of the present application, by adopting a series voltage reference as a reference voltage source (the accuracy and stability of the series voltage reference are higher than those of the parallel voltage reference), the input end of the series voltage reference 11 is connected to the power supply module 15, the output end of the series voltage reference 11 is connected to the first input end of the constant current control module 12, and the reference potential end of the series voltage reference 11 is connected to the second end of the sampling module 14 and the light source module 16 respectively, so as to improve 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.

[0068] In one possible implementation, see Figure 3 , the power supply module 15 includes a DC voltage source 151 and an isolated power supply 152;

[0069] The positive input terminal of the isolated power supply 152 is connected to the power supply terminal, and the positive output terminal of the isolated power supply 152 is respectively connected to the positive power terminal of the constant current control module 12 and the input terminal of the series voltage reference 11;

[0070] The DC voltage source 151 is connected to the first end of the switch module 13 and the power supply end respectively;

[0071] The isolated power supply 152 is used to supply power to the constant current control module 12 and the series voltage reference 11 respectively;

[0072] The DC voltage source 151 is used to supply power to the light source module 16 .

[0073] In an example, the DC voltage source 151 may be a DCDC (Direct Current to Direct Current Converter) boost circuit, which boosts the 24V DC voltage at the power supply end to the 60V-150V DC voltage required by the light source module 16 .

[0074] In one example, the isolated power supply 152 can be a small power standard isolated power supply module that converts 24V DC to 12V DC, providing a 12V DC voltage for the constant current control module 12 and the series voltage reference 11 .

[0075] In the embodiment of the present application, the constant current control module 12 and the series voltage reference 11 are powered by the isolated power supply 152, and the light source module 16 is powered by the DC voltage source 151, and 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 the related art in which the reference voltage source, the constant current control module, and the deuterium lamp are all powered by the 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 weakened; and because the isolated power supply 152 completely isolates its own input and output ends through a transformer, there is no direct electrical connection between the input and output ends. Therefore, the isolated power supply 152 (non-electrical connection method) is used to power the constant current control module 12 and the series voltage reference 11, which can improve the reliability, safety, anti-interference and stability of the light source driving circuit 1.

[0076] In one possible implementation, see Figure 4 , the power supply module 15 includes a DC voltage source 151;

[0077] The DC voltage source 151 is respectively connected to the first end of the switch module 13, the positive power supply end of the constant current control module 12, the input end and the power supply end of the series voltage reference 11;

[0078] 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.

[0079] In the embodiment of the present application, the same voltage source is used to power the constant current control module 12, the series voltage reference 11, and the light source module 16, which can simplify the circuit structure of the light source driving circuit 1 and reduce the cost.

[0080] In one possible implementation, see Figure 5 , the constant current control module 12 includes a first amplifier A1, a first resistor R1, and a first capacitor C1;

[0081] 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 respectively 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 respectively connected to the first terminal of the first capacitor C1 and the control terminal of the switch module 13, and the positive power supply terminal VDD of the first amplifier A1 is connected to the power supply module 15;

[0082] 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 switch module 13 respectively.

[0083] The first capacitor C1 is a feedback capacitor, and the first resistor R1 is an input resistor.

[0084] In the constant current control module 12, the input first voltage signal (sampling voltage signal) generates an input current through the first resistor R1, and the input current charges the first capacitor C1. The voltage of the first capacitor C1 is the difference between the voltage of the output terminal OUT of the first amplifier A1 and the voltage of the inverting input terminal -. Combined 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:

[0085]

[0086] Wherein, R1 represents the first resistor, C1 represents the first capacitor, t represents time, Vc(t) represents the second voltage signal, V ref (t) is a reference voltage signal, and Vs(t) represents a first voltage signal.

[0087] The constant current control module 12 is used to compare the first voltage signal with the reference voltage signal, and adjust 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.

[0088] In one possible implementation, see Figure 5 , the sampling module 14 includes a second resistor R2;

[0089] 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, and the second end of the second resistor R2 is connected to the light source module 16 and the reference potential end of the series voltage reference 11 respectively.

[0090] The second resistor R2 is a sampling resistor. The sampling resistor uses a precision resistor and is used to convert the operating current of the light source module 16 into a voltage signal (voltage drop of the sampling resistor) to achieve accurate feedback of the actual operating current of the light source module 16 .

[0091] The reference potential end of the series voltage reference 11 is connected to the second end of the second resistor R2, that is, the reference potential end of the series voltage reference 11 and the second end of the second resistor R2 maintain the same potential (one end of the light source module 16), which brings the following beneficial effects: the measurement of the reference voltage signal and the sampling voltage signal (first voltage signal) are both based on the same potential as a reference, which can ensure that the voltage difference between the reference voltage signal and the sampling voltage signal input by 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 the need to additionally compensate for the influence of the potential difference on the comparison result, thereby simplifying the control logic.

[0092] In one possible implementation, see Figure 5 , the switch module 13 includes an N-type switch tube M1;

[0093] The control end of the N-type switch tube M1 is connected to the output end of the constant current control module 12, the first end of the N-type switch tube M1 is connected to the power module 15, and the second end of the N-type switch tube M1 is respectively connected to the second input end of the constant current control module 12 and the first end of the sampling module 14.

[0094] Compared with the P-type switch tube with poor performance used in the related art, the N-type switch tube M1 with high driving capability, fast switching speed and small switching loss is used in the embodiment of the present application, which can improve the response speed of the switch module 13 and improve the reliability of the entire light source driving circuit 1.

[0095] The N-type switch tube M1 may be an N-type field effect transistor NMOS tube, or may be other types of N-type switch tubes, which are not specifically limited in the present application.

[0096] In one possible implementation, see Figure 5 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.

[0097] In one possible implementation, see Figure 3 , the negative input terminal of the isolated power supply 152 is grounded GND.

[0098] In one possible implementation, see Figure 3 The negative output terminal of the isolated power supply 152 is respectively 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.

[0099] In a possible implementation manner, the power supply mode of the power supply end is a direct current power supply mode.

[0100] The present application also provides a light source system 2, see Figure 6 The light source system 2 includes the light source driving circuit 1 described in any one of the above embodiments.

[0101] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0102] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0103] The above description is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A light source driving circuit, characterized in that: The circuit comprises: Series voltage reference, constant current control module, switch module, sampling module, power module and light source module; The input end of the series voltage reference is connected to the power module, the output end of the series voltage reference is connected to the constant current control module, and the reference potential end of the series voltage reference is connected to the sampling module; the constant current control module is also connected to the sampling module, the switch module, and the power module respectively; the switch module, the sampling module, and the light source module are connected in series, and any one of the switch module, the sampling module, and the light source module is connected to the power 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 working 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, and when the voltage difference between the first voltage signal and the reference voltage signal is greater than a preset threshold, adjust the second voltage signal output by itself, so that the switch module 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 no greater than the preset threshold.

2. The circuit according to claim 1, characterized in that The output end of the series voltage reference is connected to the first input end of the constant current control module, and the reference potential end of the series voltage reference is respectively connected to the second end of the sampling module and the light source module; the second input end of the constant current control module is respectively connected to the first end of the sampling module and the second end of the switch module, the output end of the constant current control module is connected to the control end of the switch module, and the first end of the switch module is connected to the power supply module; the positive power supply end of the constant current control module is connected to the power supply module.

3. The circuit according to claim 2, characterized in that 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 respectively connected to the positive power supply terminal of the constant current control module and the input terminal of the series voltage reference; The DC voltage source is connected to the first end of the switch module and the power supply end 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.

4. The circuit according to claim 2, characterized in that The power supply module includes a DC voltage source; The DC voltage source is respectively connected to the first end of the switch module, the positive power supply end of the constant current control module, the input end of the series voltage reference, and the power supply end; 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, characterized in that 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 respectively 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 respectively connected to the first terminal of the first capacitor and the control terminal of the switch module, and the positive power supply terminal 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 switch module respectively.

6. The circuit according to claim 2, characterized in that 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 light source module and the reference potential end of the series voltage reference respectively.

7. The circuit according to claim 2, characterized in that The switch module includes an N-type switch tube; The control end of the N-type switch tube is connected to the output end of the constant current control module, the first end of the N-type switch tube is connected to the power module, and the second end of the N-type switch tube is respectively connected to the second input end of the constant current control module and the first end of the sampling module.

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

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

10. The circuit according to claim 3 or 4, characterized in that: The power supply mode of the power supply end is a direct current power supply mode.

11. A light source system, characterized in that: The light source system comprises the light source driving circuit as described in any one of claims 1 to 10.

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