Laser diode driving circuit capable of adaptively adjusting voltage and electronic equipment

Abstract

The embodiment of the invention provides a laser diode driving circuit with self-adaptive voltage adjustment and electronic equipment, relates to the technical field of electronics, and is used for solving the problem of how to improve the conversion efficiency of converting electric energy into light energy in the driving circuit of a laser diode. The circuit comprises a constant-voltage closed-loop control circuit, a constant-current closed-loop control circuit, a step-up / step-down switching circuit, a direct-current voltage input end of the step-up / step-down switching circuit and a laser diode, the constant-voltage closed-loop control circuit is respectively connected with the step-up / step-down switching circuit and the laser diode; the constant-voltage closed-loop control circuit is used for controlling the control end voltage of the step-up / step-down switching circuit; the direct-current voltage input end of the step-up / step-down switching circuit is connected with the step-up / step-down switching circuit; the step-up / step-down switching circuit is connected with the laser diode; the step-up / step-down switching circuit is used for controlling the voltage of the laser diode; the laser diode is connected with the constant-current closed-loop control circuit; and the constant-current closed-loop control circuit is used for adjusting the current of the laser diode.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a laser diode driving circuit and electronic equipment with adaptive voltage regulation. Background Art

[0002] Laser diode is an electronic device that uses semiconductor PN junction to convert electric current into light energy and generate laser. In order to make the laser diode work properly, one possible implementation method is to power the laser diode through a fixed voltage in the laser diode driving circuit, but the above method will cause other devices in the driving circuit to consume a large amount of electric power, resulting in low efficiency in converting electric energy into light energy. Therefore, how to improve the conversion efficiency of converting electric energy into light energy in the laser diode driving circuit has become a technical problem that needs to be solved at present. Summary of the invention

[0003] In view of the above problems, the purpose of the present invention is to provide a laser diode driving circuit and electronic equipment with voltage adaptive regulation to improve the conversion efficiency of electric energy into light energy and save electric energy. The specific scheme is as follows: In a first aspect, an embodiment of the present application provides a laser diode driving circuit with voltage adaptive regulation, the circuit comprising: a constant voltage closed-loop control circuit, a constant current closed-loop control circuit, a boost / buck switch circuit, a DC voltage input terminal of the boost / buck switch circuit, and a laser diode; The constant voltage closed-loop control circuit is connected to the boost / buck switch circuit and the laser diode respectively; the constant voltage closed-loop control circuit is used to control the control terminal voltage of the boost / buck switch circuit; The DC voltage input terminal of the boost / buck switch circuit is connected to the boost / buck switch circuit; the boost / buck switch circuit is connected to the laser diode; the boost / buck switch circuit is used to control the voltage of the laser diode; The laser diode is connected to the constant current closed-loop control circuit; the constant current closed-loop control circuit is used to adjust the current of the laser diode.

[0004] Optionally, the constant voltage closed-loop control circuit is connected to the voltage boost / buck switch circuit and the laser diode respectively, and includes: The first end of the constant voltage closed-loop control circuit is connected to the control end of the boost / buck switch circuit; The second end of the constant voltage closed-loop control circuit is connected to the positive electrode of the laser diode; the third end of the constant voltage closed-loop control circuit is connected to the negative electrode of the laser diode.

[0005] Optionally, the voltage step-up / step-down switch circuit is connected to the laser diode, comprising: The DC voltage output end of the voltage step-up / step-down switch circuit is connected to the cathode of the laser diode.

[0006] Optionally, the laser diode is connected to the constant current closed-loop control circuit, including: The positive electrode of the laser diode is connected to the constant current closed-loop control circuit.

[0007] Optionally, the constant voltage closed-loop control circuit comprises: a first proportional integral amplifier circuit, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a setting voltage input terminal of the constant voltage closed-loop control circuit; A setting voltage input terminal of the constant voltage closed-loop control circuit is connected to one end of the first resistor; The other end of the first resistor is connected to one end of the first proportional integral amplifier circuit and the second resistor respectively; The other end of the second resistor is respectively connected to one end of the third resistor and the ground wire; The other end of the third resistor is connected to one end of the first proportional integral amplifier circuit and the fourth resistor respectively; The fourth resistor is connected in parallel with the laser diode; One end of the fifth resistor is connected to the first proportional integral amplifier circuit; the other end of the fifth resistor is connected to the control end of the boost / buck switch circuit.

[0008] Optionally, the first proportional integral amplifier circuit includes: a first operational amplifier, a sixth resistor, a seventh resistor and a first capacitor; One end of the sixth resistor is connected to a connection end between the first resistor and the second resistor; The other end of the sixth resistor is connected to the inverting end of the first operational amplifier and one end of the first capacitor respectively; The other end of the first capacitor is connected to one end of the seventh resistor; The other end of the seventh resistor is connected to one end of the fifth resistor; The output terminal of the first operational amplifier is connected to the connection terminal between the seventh resistor and the fifth resistor; the in-phase terminal of the first operational amplifier is connected to the connection terminal between the third resistor and the fourth resistor.

[0009] Optionally, the constant current closed-loop control circuit includes: a field effect tube, a proportional amplifier circuit, an eighth resistor, a ninth resistor and a tenth resistor; The drain of the field effect tube is connected to the anode of the laser diode; The gate of the field effect tube is connected to one end of the eighth resistor; the other end of the eighth resistor is connected to the proportional amplifier circuit; One end of the ninth resistor is connected to one end of the tenth resistor; the other end of the ninth resistor is connected to the proportional amplifier circuit; The source of the field effect tube is connected to the connection end of the ninth resistor and the tenth resistor; The other end of the tenth resistor is grounded.

[0010] Optionally, the proportional amplification circuit includes: a second capacitor, a second operational amplifier, an eleventh resistor and a twelfth resistor; One end of the second capacitor is connected to the other end of the eighth resistor and the output end of the second operational amplifier respectively; The other end of the second capacitor is connected to the other end of the ninth resistor and the inverting end of the second operational amplifier respectively; One end of the eleventh resistor is connected to one end of the twelfth resistor; The other end of the eleventh resistor is connected to the setting voltage input end of the constant current closed-loop control circuit; The other end of the twelfth resistor is grounded; The non-inverting terminal of the second operational amplifier is connected to one end of the eleventh resistor; the fourth pin of the second operational amplifier is grounded; and the eighth pin of the second operational amplifier is connected to a power supply.

[0011] Optionally, the field effect transistor is any one of a transistor, a field effect transistor, and an insulated gate bipolar transistor.

[0012] In a second aspect, an embodiment of the present application provides an electronic device, comprising any one of the above-mentioned voltage adaptively regulated laser diode drive circuits.

[0013] Compared with the prior art, this application has the following beneficial effects: The present application sets a constant voltage closed-loop control circuit, a constant current closed-loop control circuit, a boost / buck switch circuit, a DC voltage input terminal of the boost / buck switch circuit and a laser diode in a laser diode driving circuit, connects the constant voltage closed-loop control circuit to the boost / buck switch circuit and the laser diode respectively, connects the DC voltage input terminal of the boost / buck switch circuit to the boost / buck switch circuit, connects the boost / buck switch circuit to the laser diode, and connects the laser diode to the constant current closed-loop control circuit. The control terminal voltage of the boost / buck switch circuit is controlled by the constant voltage closed-loop control circuit, the boost / buck switch circuit controls the voltage of the laser diode, and the constant current closed-loop control circuit adjusts the current of the laser diode, thereby outputting a dynamically changed and adjusted voltage to the laser diode through the boost / buck switch circuit, realizing voltage adaptive regulation and control of the laser diode driving circuit, reducing the electric power loss generated by other devices in the circuit, and improving the conversion efficiency of electric energy into light energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] 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 recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0015] Figure 1 A schematic diagram of the structure of a laser diode driving circuit for powering a laser diode with a fixed voltage provided in an embodiment of the present application; Figure 2 A schematic diagram of the structure of a laser diode driving circuit with voltage adaptive regulation provided in an embodiment of the present application; Figure 3 A schematic diagram of the structure of a constant voltage closed-loop control circuit provided in an embodiment of the present application; Figure 4 A schematic diagram of the structure of a first proportional-integral amplifier circuit provided in an embodiment of the present application; Figure 5 A schematic diagram of the structure of a constant current closed-loop control circuit provided in an embodiment of the present application; Figure 6 A schematic diagram of the structure of a proportional amplifier circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0016] 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. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0017] The terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0018] A laser diode driver circuit that powers the laser diode with a fixed voltage is shown in FIG. Figure 1 As shown, Figure 1The VCC DC voltage is connected to the positive electrode of the laser diode, and the negative electrode of the laser diode is connected to the drain of the field effect tube. When the constant current control module has a set voltage input, the constant current control module controls the change of the resistance value of the drain and source of the field effect tube by driving the gate voltage of the field effect tube to realize the current limiting and voltage division in the series circuit. The VCC current forms a loop through the laser diode, the field effect tube, and the sampling resistor. The current flows through the sampling resistor to generate a voltage that is fed back to the constant current control module to form a constant current closed-loop control.

[0019] Depend on Figure 1 It can be seen that the laser diode, field effect tube, and sampling resistor are in series. When the VCC voltage is a fixed value of 5V, the on-voltage of the laser diode is about 2V, and the current flowing through the series loop is 1A, the voltage on the field effect tube and the sampling resistor is 3V. According to the power calculation formula P=UI, the power consumption on the field effect tube and the sampling resistor is about 3W. When the current flowing through the series loop is 10A, the power consumption on the field effect tube and the sampling resistor is about 30W, and so on.

[0020] Since the VCC voltage is fixed, the electric power consumed by the field effect tube and the sampling resistor will increase as the current continues to increase, resulting in the field effect tube and the sampling resistor in the driving circuit needing to consume a large amount of electric power, and the efficiency of converting electric energy into light energy is low. In addition, if the power consumption on the sampling resistor is reduced by reducing the value of the sampling resistor, the power consumption on the field effect tube will also increase accordingly, and a higher-power field effect tube is required to meet the high-current bearing capacity, and the price of high-power field effect tubes will also be higher. In addition, the waste heat generated by the consumption of electric power on the field effect tube also requires the addition of an additional heat dissipation cooling system, which is not convenient for miniaturization of the equipment. In order to solve the above problems, the present application provides a laser diode drive circuit and electronic equipment with voltage adaptive regulation, as follows.

[0021] like Figure 2 As shown, the present application provides a laser diode driving circuit with voltage adaptive regulation, the circuit comprising: a constant voltage closed-loop control circuit 201, a constant current closed-loop control circuit 203, a boost / buck switch circuit 202, a DC voltage input terminal Vin of the boost / buck switch circuit 202 and a laser diode D1; The constant voltage closed loop control circuit 201 is connected to the boost / buck switch circuit 202 and the laser diode D1 respectively; the constant voltage closed loop control circuit 201 is used to control the control terminal voltage of the boost / buck switch circuit 202; The DC voltage input terminal Vin of the boost / buck switch circuit 202 is connected to the boost / buck switch circuit 202; the boost / buck switch circuit 202 is connected to the laser diode D1; the boost / buck switch circuit 202 is used to control the voltage of the laser diode D1; The laser diode D1 is connected to a constant current closed-loop control circuit 203 ; the constant current closed-loop control circuit 203 is used to adjust the current of the laser diode D1 .

[0022] Specifically, the first end of the constant voltage closed-loop control circuit 201 is connected to the control end Trim of the boost / buck switch circuit 202; the second end of the constant voltage closed-loop control circuit 201 is connected to the cathode of the laser diode D1; and the third end of the constant voltage closed-loop control circuit 201 is connected to the anode of the laser diode D1.

[0023] The DC voltage output terminal Vout of the boost / buck switch circuit 202 is connected to the positive electrode of the laser diode D1. The negative electrode of the laser diode D1 is connected to the constant current closed-loop control circuit 203. The boost / buck switch circuit 202 is specifically used to adjust the voltage inputted by the DC voltage input terminal Vin based on the input voltage of the control terminal Trim until the voltage of the DC voltage output terminal Vout is within the voltage range set by the set voltage input terminal Vset.

[0024] The control terminal voltage of the boost / buck switch circuit 202 is controlled by the constant voltage closed-loop control circuit 201 to control the output terminal of the boost / buck switch circuit 202 to output a dynamically changed and adjusted voltage to the laser diode D1, thereby realizing voltage adaptive regulation control of the laser diode drive circuit. Compared with using a fixed power supply to power the laser diode, it can effectively reduce the electric power loss generated by the current in other devices in the circuit and improve the conversion efficiency of electric energy into light energy.

[0025] like Figure 3 As shown, in an optional embodiment, the constant voltage closed-loop control circuit 201 includes: a first proportional integral amplifier circuit 301, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a setting voltage input terminal Vset of the constant voltage closed-loop control circuit 201; The setting voltage input terminal of the constant voltage closed-loop control circuit 201 is connected to one end of the first resistor R1; The other end of the first resistor R1 is connected to the first proportional integral amplifier circuit 301 and one end of the second resistor R2 respectively; The other end of the second resistor R2 is respectively connected to one end of the third resistor R3 and the ground line; The other end of the third resistor R3 is connected to the first proportional integral amplifier circuit 301 and one end of the fourth resistor R4 respectively; The fourth resistor R4 is connected in parallel with the laser diode D1; One end of the fifth resistor R5 is connected to the first proportional integral amplifier circuit 301 ; the other end of the fifth resistor R5 is connected to the control end of the boost / buck switch circuit 202 .

[0026] When the voltage at the setting voltage input terminal Vset of the constant voltage closed-loop control circuit 201 is not set, the DC voltage output terminal Vout of the step-up / step-down switch circuit 202 has no output voltage. When there is a voltage at the setting voltage input terminal Vset, the voltage is divided by the first resistor R1 and the second resistor R2 and input to the first proportional integral amplifier circuit 301.

[0027] like Figure 4 As shown, in an optional embodiment, the first proportional integral amplifier circuit 301 includes: a first operational amplifier U1A, a sixth resistor R6, a seventh resistor R7 and a first capacitor C1; One end of the sixth resistor R6 is connected to the connection end between the first resistor R1 and the second resistor R2; The other end of the sixth resistor R6 is connected to the inverting end of the first operational amplifier U1A and one end of the first capacitor C1 respectively; The other end of the first capacitor C1 is connected to one end of the seventh resistor R7; The other end of the seventh resistor R7 is connected to one end of the fifth resistor R5; The output terminal of the first operational amplifier U1A is connected to the connection terminal between the seventh resistor R7 and the fifth resistor R5; the in-phase terminal of the first operational amplifier U1A is connected to the connection terminal between the third resistor R3 and the fourth resistor R4.

[0028] The first proportional integral amplifier circuit 301 is composed of a first operational amplifier U1A, a sixth resistor R6, a seventh resistor R7 and a first capacitor C1. The first operational amplifier U1A has a non-inverting terminal at pin 5, an inverting terminal at pin 6 and an output terminal at pin 7. The first operational amplifier U1A may also be composed of a plurality of transistors or a plurality of field effect transistors.

[0029] When there is a voltage at the voltage input terminal Vset, the voltage is divided by the first resistor R1 and the second resistor R2 and then input to the first proportional integral amplifier circuit 301. Since there is no output voltage at the DC voltage output terminal Vout, the non-inverting terminal of the first operational amplifier U1A is equivalent to grounding. According to the principle that the voltage at the non-inverting terminal and the inverting terminal of the operational amplifier are equal, when the input voltage at the inverting terminal is greater than the non-inverting terminal, the voltage output by the first proportional integral amplifier circuit is close to 0 volts. After being limited by the fifth resistor R5, it is input to the control terminal Trim of the boost / buck switch circuit 202. The boost / buck switch circuit adjusts the output voltage of the DC voltage output terminal Vout according to the input value of the control terminal Trim. After the DC voltage output terminal Vout is divided by the third resistor R3 and the fourth resistor R4, it is fed back to the non-inverting terminal of the first operational amplifier U1A, so that the first proportional integral amplifier circuit 301 outputs the adjusted voltage value to the control terminal Trim according to the preset proportional amplification and integration time. The constant voltage closed-loop control circuit 201 cyclically executes the above circuit actions until the voltage output by the DC voltage output terminal Vout is stabilized within the voltage range set by the set voltage input terminal Vset, thereby realizing constant voltage closed-loop control.

[0030] It should be noted that the present application can configure the proportional integral time by setting the parameter values ​​of the sixth resistor R6, the seventh resistor R7 and the first capacitor C1. When the parameter values ​​of the sixth resistor R6, the seventh resistor R7 and the first capacitor C1 are preset values, the DC voltage output terminal Vout can be quickly adaptively adjusted when switching between light and heavy loads.

[0031] like Figure 5 As shown, the constant current closed-loop control circuit 203 includes a power tube Q1, which can be any one of a transistor, a field effect tube, and an insulated gate bipolar transistor. This application takes the power tube Q1 as a field effect tube as an example for subsequent description.

[0032] Specifically, the constant current closed-loop control circuit 203 includes: a field effect transistor Q1, a proportional amplifier circuit 501, an eighth resistor R8, a ninth resistor R9 and a tenth resistor R10; The drain of the field effect transistor Q1 is connected to the cathode of the laser diode D1; The gate of the field effect transistor Q1 is connected to one end of the eighth resistor R8; the other end of the eighth resistor R8 is connected to the proportional amplifier circuit 501; One end of the ninth resistor R9 is connected to one end of the tenth resistor R10; the other end of the ninth resistor R9 is connected to the proportional amplifier circuit 501; The source of the field effect transistor Q1 is connected to the connection end of the ninth resistor R9 and the tenth resistor R10; The other end of the tenth resistor R10 is grounded.

[0033] Specifically, the tenth resistor R10 is a sampling resistor. To reduce the power consumption of the sampling resistor, the resistance value of the sampling resistor can be selected based on the actual current of the constant current closed-loop control circuit 203, for example, the resistance value of the sampling resistor can be between several milliohms and several hundred milliohms.

[0034] Since the electric power loss generated by the field effect tube Q1 in the present application is small, the power carrying requirement of the field effect tube Q1 is reduced, so that the volume of the required field effect tube Q1 is smaller, the cost is reduced, and it is beneficial to the volume and cost control of the laser diode driving circuit. In addition, since the electric power loss generated by the field effect tube Q1 is small, the waste heat generated by the field effect tube Q1 is also reduced, and the demand for heat dissipation is low, so the present application does not need to adopt a heat dissipation cooling system, or adopts a small-volume heat dissipation cooling system, which is convenient for the miniaturization design of the laser diode driving circuit and further reduces the cost. In addition, since the constant current closed-loop control is a linear control method, the linear conduction of the field effect tube Q1 is resistive, which can effectively block the high-frequency voltage and current ripples brought by the DC power supply of the laser diode D1, and avoid the high-frequency voltage and current ripples affecting the life of the laser diode D1, and the laser emitted by the laser diode D1 is unstable and the signal-to-noise ratio is poor, which affects the stability and efficiency of the laser amplification.

[0035] like Figure 6 As shown, in an optional embodiment, the proportional amplification circuit 501 includes: a second capacitor C2, a second operational amplifier U1B, an eleventh resistor R11 and a twelfth resistor R12; One end of the second capacitor C2 is respectively connected to the other end of the eighth resistor R8 and the output end of the second operational amplifier U1B; The other end of the second capacitor C2 is connected to the other end of the ninth resistor R9 and the inverting end of the second operational amplifier U1B respectively; One end of the eleventh resistor R11 is connected to one end of the twelfth resistor R12; The other end of the eleventh resistor R11 is connected to the set voltage input terminal Iset of the constant current closed-loop control circuit 203; The other end of the twelfth resistor R12 is grounded; The in-phase terminal of the second operational amplifier U1B is connected to one end of the eleventh resistor R11; the fourth pin of the second operational amplifier U1B is grounded; and the eighth pin of the second operational amplifier U1B is connected to the power supply.

[0036] Specifically, the proportional amplifier circuit 501 is composed of a second capacitor C2, a second operational amplifier U1B, an eleventh resistor R11 and a twelfth resistor R12. The output end of the second operational amplifier U1B is pin 1, the in-phase end is pin 3, and the inverting end is pin 2. The resistance of the third resistor R3 and the fourth resistor R4 is greater than the resistance of the current loop formed by the laser diode D1, the field effect transistor Q1 and the tenth resistor R10. The second operational amplifier U1B can also be composed of multiple transistors or multiple field effect transistors.

[0037] The second capacitor C2 plays a role in suppressing current overshoot and oscillation during the current switching process, so that the rising edge and falling edge time of the switching current can be adjusted within a certain range by changing the capacitance value of the second capacitor C2.

[0038] When the voltage of the setting voltage input terminal Iset of the constant current closed-loop control circuit 203 is not set, the output voltage of the second operational amplifier U1B is close to 0 volts, the field effect tube Q1 is turned off, and no current flows through the laser diode D1. When there is a voltage input to the setting voltage input terminal Iset of the constant current closed-loop control circuit 203, the voltage is divided by the eleventh resistor R11 and the twelfth resistor R12, and then input to the in-phase terminal of the second operational amplifier U1B. The output voltage of the output terminal of the second operational amplifier U1B drives the gate of the field effect tube Q1 after being limited by the eighth resistor, and the current of the DC voltage output terminal Vout passes through the laser diode D1, the field effect tube Q1 and the tenth resistor to form a loop. The current flows through the tenth resistor R10 to generate a voltage, which is fed back to the inverting terminal of the second operational amplifier through the ninth resistor R9 to form a constant current closed-loop control, and the field effect tube Q1 is linearly turned on at this time.

[0039] Since the resistance of the third resistor R3 and the fourth resistor R4 is much greater than the resistance of the current loop formed by the laser diode D1, the field effect transistor Q1 and the tenth resistor R10, the voltage division of the resistors in the current loop formed by the laser diode D1, the field effect transistor Q1 and the tenth resistor R10 is much lower than the voltage division of the resistors in the current loop where the third resistor R3 and the fourth resistor R4 are located. At this time, the voltage fed back to the in-phase terminal of the first operational amplifier U1A is the voltage on the drain of the field effect transistor Q1. The first operational amplifier U1A automatically adjusts the voltage outputted by the DC voltage output terminal Vout of the boost / buck switch circuit 202 according to the proportional integral time and feedback voltage of the first capacitor C1, the sixth resistor R6 and the seventh resistor R7 to adapt to the adjustment of the current size of the laser diode D1 in the constant current closed-loop control circuit 203.

[0040] based on Figure 6From the voltage adaptively regulated laser diode driving circuit shown in the figure, and the electric power calculation formula P=UI, it can be seen that in the laser diode driving circuit provided by the present application, the current passes through the series circuit formed by the laser diode D1, the field effect transistor Q1, and the tenth resistor R10. The present application can effectively reduce the electric power loss generated by the current in the field effect transistor by reducing the terminal voltage between the drain and the source of the field effect transistor Q1, thereby improving the efficiency of converting electric power into light energy.

[0041] A controllable step-up / step-down switch circuit 202 is used to realize voltage conversion from the DC voltage input terminal Vin to the DC voltage output terminal Vout, and the conversion efficiency can reach 95%-98%. The output voltage of the DC voltage output terminal Vout is dynamically adjusted in a closed loop to power the laser diode, thereby realizing voltage-adaptive laser diode drive control. In addition, since the output voltage value of the DC voltage output terminal Vout supports voltage-adaptive adjustment, the present application supports simultaneous driving of multiple laser diodes in series.

[0042] Since the switching main frequency of the step-up / step-down switching circuit 202 is high enough, the output voltage of the DC voltage output terminal Vout can be quickly and adaptively adjusted when switching between light and heavy loads. The technical solution supports pulse constant current mode operation. According to the voltage and current parameters of the laser diode D1, a reasonable output voltage can be set for the DC voltage output terminal Vout, so that the device parameters in the circuit can be adjusted by adjusting the energy storage capacitor value, and a current modulation frequency signal is loaded on the voltage input terminal Iset, so that a pulse constant current mode operation with a frequency of 0-5M can be achieved.

[0043] The present application also provides an electronic device, which includes any one of the above-mentioned laser diode driving circuits with adaptive voltage regulation.

[0044] Each embodiment in this specification is described in a progressive 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 electronic device embodiment, since it is basically similar to the circuit embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the circuit embodiment. The electronic device embodiment described above is merely schematic, and the units and modules described as separate components may or may not be physically separated. In addition, some or all of the units and modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. A person of ordinary skill in the art can understand and implement it without paying creative labor.

[0045] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0046] The above are only preferred embodiments of the present application, and are not intended to limit the present application in any form. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the art can use the above disclosed methods and technical contents to make many possible changes and modifications to the technical solution of the present application without departing from the scope of the technical solution of the present application, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of protection of the technical solution of the present application.

Claims

1. A laser diode driving circuit with voltage adaptive regulation, characterized in that: The circuit comprises: a constant voltage closed-loop control circuit, a constant current closed-loop control circuit, a boost / buck switch circuit, a DC voltage input terminal of the boost / buck switch circuit and a laser diode; The constant voltage closed-loop control circuit is connected to the boost / buck switch circuit and the laser diode respectively; the constant voltage closed-loop control circuit is used to control the control terminal voltage of the boost / buck switch circuit; The DC voltage input terminal of the boost / buck switch circuit is connected to the boost / buck switch circuit; the boost / buck switch circuit is connected to the laser diode; the boost / buck switch circuit is used to control the voltage of the laser diode; The laser diode is connected to the constant current closed-loop control circuit; the constant current closed-loop control circuit is used to adjust the current of the laser diode.

2. The circuit according to claim 1, characterized in that The constant voltage closed-loop control circuit is connected to the voltage increase / decrease switch circuit and the laser diode respectively, and includes: The first end of the constant voltage closed-loop control circuit is connected to the control end of the boost / buck switch circuit; The second end of the constant voltage closed-loop control circuit is connected to the positive electrode of the laser diode; the third end of the constant voltage closed-loop control circuit is connected to the negative electrode of the laser diode.

3. The circuit according to claim 1, characterized in that The voltage step-up / step-down switch circuit is connected to the laser diode and includes: The DC voltage output end of the voltage step-up / step-down switch circuit is connected to the cathode of the laser diode.

4. The circuit according to claim 1, characterized in that The laser diode is connected to the constant current closed-loop control circuit, comprising: The positive electrode of the laser diode is connected to the constant current closed-loop control circuit.

5. The circuit according to claim 2, characterized in that The constant voltage closed-loop control circuit comprises: a first proportional integral amplifier circuit, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a setting voltage input terminal of the constant voltage closed-loop control circuit; A setting voltage input terminal of the constant voltage closed-loop control circuit is connected to one end of the first resistor; The other end of the first resistor is connected to one end of the first proportional integral amplifier circuit and the second resistor respectively; The other end of the second resistor is respectively connected to one end of the third resistor and the ground wire; The other end of the third resistor is connected to one end of the first proportional integral amplifier circuit and the fourth resistor respectively; The fourth resistor is connected in parallel with the laser diode; One end of the fifth resistor is connected to the first proportional integral amplifier circuit; the other end of the fifth resistor is connected to the control end of the boost / buck switch circuit.

6. The circuit according to claim 5, characterized in that The first proportional integral amplifier circuit comprises: a first operational amplifier, a sixth resistor, a seventh resistor and a first capacitor; One end of the sixth resistor is connected to a connection end between the first resistor and the second resistor; The other end of the sixth resistor is connected to the inverting end of the first operational amplifier and one end of the first capacitor respectively; The other end of the first capacitor is connected to one end of the seventh resistor; The other end of the seventh resistor is connected to one end of the fifth resistor; The output terminal of the first operational amplifier is connected to the connection terminal between the seventh resistor and the fifth resistor; the in-phase terminal of the first operational amplifier is connected to the connection terminal between the third resistor and the fourth resistor.

7. The circuit according to claim 4, characterized in that The constant current closed-loop control circuit comprises: a field effect tube, a proportional amplifier circuit, an eighth resistor, a ninth resistor and a tenth resistor; The drain of the field effect tube is connected to the anode of the laser diode; The gate of the field effect tube is connected to one end of the eighth resistor; the other end of the eighth resistor is connected to the proportional amplifier circuit; One end of the ninth resistor is connected to one end of the tenth resistor; the other end of the ninth resistor is connected to the proportional amplifier circuit; The source of the field effect tube is connected to the connection end of the ninth resistor and the tenth resistor; The other end of the tenth resistor is grounded.

8. The circuit according to claim 7, characterized in that The proportional amplification circuit comprises: a second capacitor, a second operational amplifier, an eleventh resistor and a twelfth resistor; One end of the second capacitor is connected to the other end of the eighth resistor and the output end of the second operational amplifier respectively; The other end of the second capacitor is connected to the other end of the ninth resistor and the inverting end of the second operational amplifier respectively; One end of the eleventh resistor is connected to one end of the twelfth resistor; The other end of the eleventh resistor is connected to the setting voltage input end of the constant current closed-loop control circuit; The other end of the twelfth resistor is grounded; The non-inverting terminal of the second operational amplifier is connected to one end of the eleventh resistor; the fourth pin of the second operational amplifier is grounded; and the eighth pin of the second operational amplifier is connected to a power supply.

9. The circuit according to claim 7, characterized in that The field effect transistor is any one of a transistor, a field effect transistor, and an insulated gate bipolar transistor.

10. An electronic device comprising the voltage adaptively regulated laser diode drive circuit according to any one of claims 1 to 9.

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