Laser driving circuit and laser

Abstract

The present application discloses a driving circuit and a laser for a laser, and relates to the field of semiconductor driving, and includes a sine wave generator, a driving tube, a feedback module and a comparison module; the output end of the sine wave generator is connected to the positive phase input end of the comparison module, the output end of the comparison module is connected to the control end of the driving tube, the first end of the driving tube is connected to the cathode of the light-emitting component of the laser, the anode of the light-emitting component of the laser is connected to the power supply, the second end of the driving tube is connected to the first end of the feedback module, and the second end of the feedback module is connected to the inverting input end of the comparison module. The sine wave control driving tube can reduce the on-time and off-time of the driving tube, and then reduce the heat generated by the driving tube to ensure the working temperature of the laser, and the current of the light-emitting component is fed back through the feedback module to realize constant current control of the light-emitting component.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor driving, in particular to a driving circuit of a laser and a laser. Background Art

[0002] Among all types of lasers, semiconductor lasers have the best energy conversion efficiency. Usually, the photoelectric conversion efficiency is 50%, that is, 50W of electrical power can generate 25W of optical power, and the rest is converted into heat. The heat generated when the laser is working comes from two parts, namely the constant current drive tube and the laser body. Considering that the stability of the laser's output optical power is highly correlated with the temperature when the laser is working, it is usually necessary to stabilize the laser's temperature at a certain value during use to ensure the stability of its output. Therefore, lowering the temperature of the laser becomes an important issue in driving the laser. Utility Model Content

[0003] The purpose of the present application is to provide a laser driving circuit and a laser. The sine wave control driving tube can reduce the on-time and off-time of the driving tube, thereby reducing the heat generated by the driving tube to ensure the working temperature of the laser. The current of the light-emitting component is fed back through the feedback module to achieve constant current control of the light-emitting component.

[0004] In order to solve the above technical problems, the present application provides a laser driving circuit, including a sine wave generator, a driving tube, a feedback module and a comparison module;

[0005] The output end of the sine wave generator is connected to the positive phase input end of the comparison module, and is used to output a sine wave;

[0006] The output end of the comparison module is connected to the control end of the driving tube, and is used to compare the voltage value of the sine wave with the feedback voltage;

[0007] The first end of the driving tube is connected to the cathode of the light-emitting component of the laser, the anode of the light-emitting component is connected to the power supply, and the second end of the driving tube is connected to the first end of the feedback module to drive the light-emitting component to emit light;

[0008] The second end of the feedback module is connected to the inverting input end of the comparison module. The feedback module is used to output a feedback voltage. The feedback voltage is positively correlated with the current flowing through the light-emitting component.

[0009] On the other hand, the feedback module includes a conversion module;

[0010] The first end of the conversion module is connected to the second end of the driving tube, the second end and the third end of the conversion module are both grounded, and the fourth end of the conversion module is connected to the inverting input end of the comparison module, which is used to convert the current flowing through the light-emitting component into a feedback voltage.

[0011] On the other hand, the feedback module further includes a first operational amplifier, a first resistor and a second resistor;

[0012] The non-inverting input terminal of the first operational amplifier is connected to the fourth terminal of the conversion module, the inverting input terminal of the first operational amplifier is connected to the first terminal of the first resistor and the first terminal of the second resistor respectively, the second terminal of the first resistor is grounded, and the second terminal of the second resistor is connected to the inverting input terminal of the comparison module;

[0013] The first operational amplifier, the first resistor and the second resistor are used to amplify the feedback voltage output by the conversion module and then input the amplified feedback voltage to the comparison module.

[0014] In another aspect, a first auxiliary module is also included;

[0015] The first end of the first auxiliary module is connected to the output end of the comparison module, the second end of the first auxiliary module is connected to the control end of the driving tube, and the first auxiliary module is used to assist the driving tube in conducting.

[0016] On the other hand, the first auxiliary module includes a first transistor and a second transistor;

[0017] The first end of the first triode is connected to a power supply, the second end of the first triode is connected to the first end of the second triode, and the common end of the connections is connected to the control end of the driving tube, the second end of the second triode is grounded, and the control ends of the first triode and the second triode are both connected to the output end of the comparison module;

[0018] The first transistor and the second transistor are used to form a push-pull circuit to assist the driving transistor in conducting.

[0019] In another aspect, a second auxiliary module is also included;

[0020] The first end of the second auxiliary module is connected to the output end of the comparison module, the second end of the second auxiliary module is connected to the control end of the driving tube, the third end of the second auxiliary module is connected to the second end of the driving tube, and the second auxiliary module is used to assist the driving tube in conducting.

[0021] On the other hand, the second auxiliary module includes a third resistor and a fourth resistor;

[0022] The first end of the third resistor is connected to the second end of the first transistor, the second end of the third resistor is respectively connected to the first end of the fourth resistor and the control end of the driving tube, and the second end of the fourth resistor is connected to the second end of the driving tube;

[0023] The third resistor and the fourth resistor are used to assist the driving tube in conducting.

[0024] On the other hand, it also includes multipliers;

[0025] The first input terminal of the multiplier is connected to the output terminal of the sine wave generator, the second input terminal of the multiplier is connected to the control signal, and the output terminal of the multiplier is connected to the positive phase input terminal of the comparison module;

[0026] The multiplier is used to multiply the sine wave by the control signal, and the control signal is used to adjust the amplitude of the sine signal.

[0027] To solve the above technical problems, the present application also provides a laser, including the above laser driving circuit and a light-emitting component, wherein the laser driving circuit is connected to the cathode of the light-emitting component, and the anode of the light-emitting component is connected to a power supply.

[0028] On the other hand, the light emitting component is a light emitting diode.

[0029] The present application provides a driving circuit and a laser for a laser, which relates to the field of semiconductor driving, and includes a sine wave generator, a driving tube, a feedback module and a comparison module; the output end of the sine wave generator is connected to the positive phase input end of the comparison module, the output end of the comparison module is connected to the control end of the driving tube, the first end of the driving tube is connected to the cathode of the light-emitting component of the laser, the anode of the light-emitting component of the laser is connected to the power supply, the second end of the driving tube is connected to the first end of the feedback module, and the second end of the feedback module is connected to the inverting input end of the comparison module. The sine wave control driving tube can reduce the on-time and off-time of the driving tube, thereby reducing the heat generated by the driving tube to ensure the working temperature of the laser, and the current of the light-emitting component is fed back through the feedback module to realize constant current control of the light-emitting component. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the prior art and the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A schematic diagram of the structure of a laser driving circuit provided in this application;

[0032] Figure 2 A schematic diagram of the structure of another laser driving circuit provided in the present application;

[0033] Figure 3A schematic diagram of the structure of another laser driving circuit provided in the present application. DETAILED DESCRIPTION

[0034] The core of this application is to provide a laser driving circuit and a laser. The sine wave control driving tube can reduce the on-time and off-time of the driving tube, thereby reducing the heat generated by the driving tube to ensure the working temperature of the laser. The current of the light-emitting component is fed back through the feedback module to achieve constant current control of the light-emitting component.

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are 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 without creative work are within the scope of protection of this application.

[0036] Figure 1 A schematic diagram of the structure of a laser driving circuit provided in the present application, wherein the laser driving circuit is characterized by comprising a sine wave generator U2, a driving tube Q, a feedback module 1 and a comparison module OP2;

[0037] The output terminal of the sine wave generator U2 is connected to the positive phase input terminal of the comparison module OP2 for outputting a sine wave;

[0038] The output end of the comparison module OP2 is connected to the control end of the driving tube Q, and is used to compare the voltage value of the sine wave with the feedback voltage;

[0039] The first end of the driving tube Q is connected to the cathode of the light-emitting component of the laser, the anode of the light-emitting component LD is connected to the power supply, and the second end of the driving tube Q is connected to the first end of the feedback module 1, for driving the light-emitting component to emit light LD;

[0040] The second end of the feedback module 1 is connected to the inverting input end of the comparison module OP2. The feedback module 1 is used to output a feedback voltage. The feedback voltage is positively correlated with the current flowing through the light-emitting component.

[0041] Among all types of lasers, semiconductor lasers have the best energy conversion efficiency. Usually, the photoelectric conversion efficiency is 50%, that is, 50W of electrical power can generate 25W of optical power, and the rest is converted into heat. The heat generated when the laser is working comes from two parts, namely the driver tube Q and the laser body. Considering that the stability of the laser's output optical power is highly correlated with the temperature when the laser is working, it is usually necessary to stabilize the laser's temperature at a certain value during use to ensure the stability of its output. Therefore, lowering the temperature of the laser becomes an important issue in driving the laser.

[0042] Considering that the sources of heat are the driver tube Q and the laser body, but the laser will generate heat as long as it emits light, reducing the generation of heat will affect the normal light emission of the laser, so this application adopts the method of reducing the heat of the driver tube Q to reduce the operating temperature of the laser. To reduce the heat emitted by the driver tube Q, it is necessary to reduce the conduction time of the driver tube Q. In order to reduce the conduction time of the driver tube Q, this application adopts a sine wave to control the conduction of the driver tube Q. When the driver tube Q is turned on, the cathode of the light-emitting component is grounded, thereby realizing the conduction of the light-emitting component. When the sine wave controls the driver tube Q, the conduction time and the off time of the driver tube Q will be reduced, thereby reducing the conduction time of the driver tube Q, thereby reducing the heat emitted by the driver tube Q, and realizing the reduction of the operating temperature of the light-emitting component.

[0043] Semiconductor lasers are current-driven and need to be driven by a constant current source. Laser driving has continuous mode and pulse mode. In continuous mode, the control signal drives the constant current source with a certain voltage value, so that the constant current driver always outputs current so that the laser outputs laser. In pulse mode, the control signal drives the constant current source with a certain amplitude frequency, so that the constant current driver intermittently outputs current so that the laser outputs laser light. Therefore, in order to achieve stable light emission of the light-emitting component, it is necessary to control the current flowing through the light-emitting component to be at a stable value, so the present application sets a feedback module 1, which converts the current flowing through the light-emitting component into a feedback voltage, and the comparison module OP2 compares the peak value of the sinusoidal wave signal with the value of the feedback voltage, thereby realizing the feedback effect.

[0044] The present application provides a driving circuit for a laser, which relates to the field of semiconductor driving, and includes a sine wave generator U2, a driving tube Q, a feedback module 1, and a comparison module OP2; the output end of the sine wave generator U2 is connected to the positive phase input end of the comparison module OP2, the output end of the comparison module OP2 is connected to the control end of the driving tube Q, the first end of the driving tube Q is connected to the cathode of the light-emitting component of the laser, the anode of the light-emitting component of the laser is connected to the power supply, the second end of the driving tube Q is connected to the first end of the feedback module 1, and the second end of the feedback module 1 is connected to the inverting input end of the comparison module OP2. Sine wave control of the driving tube Q can reduce the on-time and off-time of the driving tube Q, thereby reducing the heat generated by the driving tube Q to ensure the working temperature of the laser, and the current of the current light-emitting component is fed back through the feedback module 1 to achieve constant current control of the light-emitting component.

[0045] Based on the above embodiments:

[0046] In some embodiments, the feedback module 1 includes a conversion module U3;

[0047] The first end of the conversion module U3 is connected to the second end of the driving tube Q, the second end and the third end of the conversion module U3 are both grounded, and the fourth end of the conversion module U3 is connected to the inverting input end of the comparison module OP2, which is used to convert the current flowing through the light-emitting component into a feedback voltage.

[0048] In order to achieve the drive current I D Converted into feedback voltage U0, the present application sets up a conversion module U3, the conversion module U3 is provided with four terminals, wherein the first terminal is connected to the driving tube Q, the second terminal and the third terminal are grounded, and the fourth terminal is connected to the comparison module OP2, and then the feedback voltage U0 is input into the comparison module OP2, thereby realizing the feedback function.

[0049] Specifically, the conversion module U3 may be a PD, which is short for a photodetector, a device that can convert light signals into electrical signals. PD is usually composed of a photodiode, a photomultiplier tube, a photoconductor, and a phototransistor, and can be used in optical communication, optical measurement, spectral analysis, and other fields.

[0050] In some embodiments, the feedback module 1 further includes a first operational amplifier OP1, a first resistor R1, and a second resistor R2;

[0051] The non-inverting input terminal of the first operational amplifier OP1 is connected to the fourth terminal of the conversion module U3, the inverting input terminal of the first operational amplifier OP1 is connected to the first terminal of the first resistor R1 and the first terminal of the second resistor R2 respectively, the second terminal of the first resistor R1 is grounded, and the second terminal of the second resistor R2 is connected to the inverting input terminal of the comparison module OP2;

[0052] The first operational amplifier OP1 , the first resistor R1 and the second resistor R2 are used to amplify the feedback voltage output by the conversion module U3 and then input the amplified feedback voltage to the comparison module OP2 .

[0053] Taking into account that the converted feedback voltage is not sufficient to realize the comparison of the comparison module OP2, the present application adds a first operational amplifier OP1, a first resistor R1 and a second resistor R2 to amplify the feedback voltage output by the conversion module U3, and the amplified feedback voltage is output to the inverting input terminal of the comparison module OP2, so that the comparison module OP2 compares the sinusoidal wave signal with the amplified feedback voltage, and then controls the conduction and shutdown of the driving tube Q based on the comparison result.

[0054] The feedback voltage is amplified by the first operational amplifier OP1, the first resistor R1 and the second resistor R2, so as to control the driving tube Q later.

[0055] In some embodiments, further comprising a first auxiliary module;

[0056] The first end of the first auxiliary module is connected to the output end of the comparison module, the second end of the first auxiliary module is connected to the control end of the driving tube, and the first auxiliary module is used to assist the driving tube in conducting.

[0057] In some embodiments, it further includes a first transistor Q1 and a second transistor Q2;

[0058] A first end of the first triode Q1 is connected to a power supply, a second end of the first triode Q1 is connected to a first end of the second triode Q2, and a common end of the connections is connected to a control end of the driving tube Q, a second end of the second triode Q2 is grounded, and the control ends of the first triode Q1 and the second triode Q2 are both connected to an output end of the comparison module OP2;

[0059] The first transistor Q1 and the second transistor Q2 are used to form a push-pull circuit to assist the driving transistor Q in conducting.

[0060] A push-pull circuit is an output circuit connected between two transistors of different polarities. The push-pull circuit uses two power BJT tubes or MOSFET tubes with the same parameters, which exist in the circuit in a push-pull manner. Each is responsible for the waveform amplification task of the positive and negative half cycles. When the circuit is working, only one of the two symmetrical power switch tubes is turned on at a time, so the conduction loss is small and the efficiency is high. The push-pull output can both inject current into the load and extract current from the load.

[0061] If there are two transistors in the output stage, one is always on and the other is off, that is, the two transistors are connected in push-pull mode. This circuit structure is called a push-pull circuit or a totem-pole output circuit. The two transistors are controlled by two complementary signals, and one transistor is always on while the other is off. To realize line-and, an OC (open collector) gate circuit is required. It not only improves the load capacity of the circuit, but also increases the switching speed.

[0062] In some embodiments, further comprising a second auxiliary module;

[0063] The first end of the second auxiliary module is connected to the output end of the comparison module, the second end of the second auxiliary module is connected to the control end of the driving tube, the third end of the second auxiliary module is connected to the second end of the driving tube, and the second auxiliary module is used to assist the driving tube in conducting.

[0064] In some embodiments, a third resistor R3 and a fourth resistor R4 are further included;

[0065] The first end of the third resistor R3 is connected to the second end of the first triode Q1, the second end of the third resistor R3 is connected to the first end of the fourth resistor R4 and the control end of the driving tube Q respectively, and the second end of the fourth resistor R4 is connected to the second end of the driving tube Q;

[0066] The third resistor R3 and the fourth resistor R4 are used to assist the driving tube Q in conducting.

[0067] Considering that a conduction voltage drop is required when the driving tube Q is turned on, in order to ensure that the voltages at the control end, the first end and the second end meet the conduction condition, a third resistor R3 and a fourth resistor R4 are provided. The third resistor R3 and the fourth resistor R4 realize voltage division, thereby changing the voltages at the control end and the second end, and assisting the driving tube Q in turning on.

[0068] Specifically, the driving tube Q is a MOS tube, which can be specifically set as a PMOS tube or an NMOS tube according to actual needs. The connection relationship between the third resistor R3 and the fourth resistor R4 will also change accordingly, and this application does not make too many restrictions here.

[0069] In some embodiments, a multiplier U1 is also included;

[0070] A first input terminal of the multiplier U1 is connected to an output terminal of the sine wave generator U2, a second input terminal of the multiplier U1 is connected to a control signal, and an output terminal of the multiplier U1 is connected to a positive phase input terminal of a comparison module OP2;

[0071] The multiplier U1 is used to multiply the sine wave with the control signal, and the control signal is used to adjust the amplitude of the sine signal.

[0072] The sine wave generator generates a sine wave Usin of a fixed frequency. Usin and the control signal Uin are respectively input to the input end of the multiplier U1, and the modulated control signal Uctl is output through the multiplier U1. The amplitude of the sine wave in Uctl is determined by the control signal Uin, wherein the sine wave is used to drive the laser on and off, effectively reducing the driving time of the constant current drive tube Q and the laser driving time, thereby reducing the heat generated by the constant current drive tube Q and the laser body. In the laser continuous mode, the amplitude of Uctl is adjusted by changing the control signal Uin, thereby increasing the driving current of the constant current drive tube Q to adjust the output laser power of the laser; in the laser pulse mode, the driving current and conduction time of the constant current drive tube Q are adjusted by changing the amplitude, frequency and duty cycle of the control signal Uin, thereby adjusting the output laser power of the laser.

[0073] Specifically, the frequency of the modulated control signal Uctl is determined by the sine wave generator U2, and the amplitude of the control signal Uctl is determined by the control signal Uin.

[0074] The present application also provides a laser, including the above-mentioned laser driving circuit and a light-emitting component, wherein the laser driving circuit is connected to the cathode of the light-emitting component, and the anode of the light-emitting component is connected to a power source.

[0075] In some embodiments, the light emitting component is a light emitting diode.

[0076] For an introduction to the laser provided in this application, please refer to the above embodiments, which will not be repeated here.

[0077] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0078] It should also be noted that, in this specification, 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 "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, 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, article or device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, article or device including the element.

[0079] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A laser driving circuit, characterized in that: It includes a sine wave generator, a driving tube, a feedback module and a comparison module; The output end of the sine wave generator is connected to the positive phase input end of the comparison module, and is used to output a sine wave; The output end of the comparison module is connected to the control end of the driving tube, and is used to compare the voltage value of the sine wave with the feedback voltage; The first end of the driving tube is connected to the cathode of the light-emitting component of the laser, the anode of the light-emitting component is connected to the power supply, and the second end of the driving tube is connected to the first end of the feedback module to drive the light-emitting component to emit light; The second end of the feedback module is connected to the inverting input end of the comparison module. The feedback module is used to output the feedback voltage. The feedback voltage is positively correlated with the current flowing through the light-emitting component.

2. The laser driving circuit according to claim 1, characterized in that: The feedback module includes a conversion module; The first end of the conversion module is connected to the second end of the driving tube, the second end and the third end of the conversion module are both grounded, and the fourth end of the conversion module is connected to the inverting input end of the comparison module, which is used to convert the current flowing through the light-emitting component into a feedback voltage.

3. The laser driving circuit according to claim 2, characterized in that: The feedback module also includes a first operational amplifier, a first resistor and a second resistor; The non-inverting input terminal of the first operational amplifier is connected to the fourth terminal of the conversion module, the inverting input terminal of the first operational amplifier is connected to the first terminal of the first resistor and the first terminal of the second resistor respectively, the second terminal of the first resistor is grounded, and the second terminal of the second resistor is connected to the inverting input terminal of the comparison module; The first operational amplifier, the first resistor and the second resistor are used to amplify the feedback voltage output by the conversion module and then input the amplified feedback voltage to the comparison module.

4. The laser driving circuit according to claim 1, characterized in that: Also included is a first auxiliary module; The first end of the first auxiliary module is connected to the output end of the comparison module, the second end of the first auxiliary module is connected to the control end of the driving tube, and the first auxiliary module is used to assist the driving tube in conducting.

5. The laser driving circuit according to claim 4, characterized in that: The first auxiliary module includes a first triode and a second triode; The first end of the first triode is connected to a power supply, the second end of the first triode is connected to the first end of the second triode, and the common end of the connections is connected to the control end of the driving tube, the second end of the second triode is grounded, and the control ends of the first triode and the second triode are both connected to the output end of the comparison module; The first transistor and the second transistor are used to form a push-pull circuit to assist the driving transistor in conducting.

6. The laser driving circuit according to claim 1, characterized in that: Also included is a second auxiliary module; The first end of the second auxiliary module is connected to the output end of the comparison module, the second end of the second auxiliary module is connected to the control end of the driving tube, the third end of the second auxiliary module is connected to the second end of the driving tube, and the second auxiliary module is used to assist the driving tube in conducting.

7. The laser driving circuit according to claim 6, characterized in that: The second auxiliary module includes a third resistor and a fourth resistor; The first end of the third resistor is connected to the second end of the first triode, the second end of the third resistor is respectively connected to the first end of the fourth resistor and the control end of the driving tube, and the second end of the fourth resistor is connected to the second end of the driving tube; The third resistor and the fourth resistor are used to assist the driving tube in conducting.

8. The laser driving circuit according to any one of claims 1 to 7, characterized in that: Also includes multipliers; The first input terminal of the multiplier is connected to the output terminal of the sine wave generator, the second input terminal of the multiplier is connected to the control signal, and the output terminal of the multiplier is connected to the positive phase input terminal of the comparison module; The multiplier is used to multiply the sine wave by the control signal, and the control signal is used to adjust the amplitude of the sine wave.

9. A laser, characterized in that: The laser driving circuit comprises the laser driving circuit as claimed in any one of claims 1 to 8, and also comprises a light-emitting component, wherein the laser driving circuit is connected to the cathode of the light-emitting component, and the anode of the light-emitting component is connected to a power supply.

10. The laser according to claim 9, characterized in that The light emitting component is a light emitting diode.

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