WO2024082726A1

WO2024082726A1 - Circuit structure, driving circuit of semiconductor laser, and laser radar transmitting module

Info

Publication number: WO2024082726A1
Application number: PCT/CN2023/107436
Authority: WO
Inventors: 王鹏; 樊英民; 张�浩
Original assignee: 西安炬光科技股份有限公司
Priority date: 2022-10-17
Filing date: 2023-07-14
Publication date: 2024-04-25
Also published as: CN117937235A

Abstract

The present application provides a circuit structure, a driving circuit of a semiconductor laser, and a laser radar transmitting module. The circuit structure comprises a charging circuit and a discharging circuit; an input end of the charging circuit is connected to a preset power supply, and an output end of the charging circuit is connected to the discharging circuit; the discharging circuit is further connected to an anode of a semiconductor laser, and a cathode of the semiconductor laser is grounded; the charging circuit is arranged on a first circuit board, and the discharging circuit and the semiconductor laser are arranged on a second circuit board. The present application can satisfy requirements for high-pulse current of semiconductor lasers, and also avoid the problem of insufficient reliability of semiconductor lasers caused by high temperatures.

Description

Circuit structure, semiconductor laser driving circuit and laser radar transmitting module

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to a Chinese patent application with application number 202211291271.8 filed with the Chinese Patent Office on October 17, 2022, entitled “Circuit structure, driving circuit of semiconductor laser and lidar transmitting module”, the entire contents of which are incorporated by reference into this application.

Technical Field

The present application relates to the field of electronic circuit technology, and in particular to a circuit structure, a driving circuit for a semiconductor laser, and a laser radar transmitting module.

Background technique

With the development of unmanned driving and machine vision, LiDAR has also developed rapidly. In practical applications, LiDAR transmitter modules often have application requirements such as high peak power, narrow pulse width, high stability, high reliability, high frequency, small size, and low cost.

As an important component of the laser radar transmitting module, the driving circuit mainly provides pulse driving current for the semiconductor laser, drives the semiconductor laser to work and forms light pulses. For high-power semiconductor lasers, a larger pulse driving current is required. If a larger pulse current is required, a charging and discharging circuit is required in the driving circuit to provide a larger pulse driving current for the semiconductor laser. In current technology, the driving circuit mainly adopts a single circuit board design, that is, each circuit unit in the driving circuit is arranged on the same circuit board.

Although designing a driving circuit including a charging and discharging circuit on the same circuit board can meet the driving current requirements of the semiconductor laser and enable the laser pulse energy to be well controlled, the thermal power consumption caused by the charging and discharging circuit is very high. The large amount of heat generated will be conducted to the area where the semiconductor laser is located on the circuit board, causing the temperature of the area where the semiconductor laser is located to rise, thereby affecting the performance of the semiconductor laser and increasing the reliability risk.

Summary of the invention

The purpose of this application is to provide a circuit structure, a semiconductor laser driving circuit and a laser radar transmitting module to address the deficiencies in the above-mentioned prior art, so as to avoid the problem of insufficient reliability caused by the influence of high temperature on the semiconductor laser while meeting the high pulse current requirements of the semiconductor laser.

To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

In a first aspect, an embodiment of the present application provides a circuit structure, the circuit structure comprising: a charging circuit and a discharging circuit; an input end of the charging circuit is connected to a preset power supply, and an output end of the charging circuit is connected to the discharging circuit; The discharge circuit is also connected to the anode of the semiconductor laser, and the cathode of the semiconductor laser is grounded;

Wherein, the charging circuit is arranged on a first circuit board, and the discharging circuit and the semiconductor laser are arranged on a second circuit board.

In a possible implementation, the first circuit board and the second circuit board are two circuit boards that are physically separated from each other.

The charging circuit and the discharging circuit are electrically connected via a flexible wire.

In a second aspect, an embodiment of the present application provides a driving circuit of a semiconductor laser, comprising: the circuit structure provided in the first aspect above, and further comprising: a semiconductor laser, a switch unit, and a signal processing circuit;

The input end of the signal processing circuit is used to receive a preset pulse signal, and the output end of the signal processing circuit is connected to the control end of the switch unit; the input end of the switch unit is connected to the cathode of the semiconductor laser, and the output end of the switch unit is grounded;

The input end of the charging circuit in the circuit structure is connected to a preset power supply, the output end of the charging circuit is connected to the discharge circuit, and the discharge circuit in the circuit structure is also connected to the anode of the semiconductor laser to supply power to the anode of the semiconductor laser;

The charging circuit is arranged on a first circuit board, and the discharging circuit, the semiconductor laser, the switch unit and the signal processing circuit are arranged on a second circuit board.

In a possible implementation, the first circuit board is disposed outside the housing of the laser radar transmitting module, and the second circuit board is disposed inside the housing of the laser radar transmitting module.

In another possible implementation, the driving circuit further includes: a temperature control unit and a bottom plate, and the temperature control unit is disposed between the second circuit board and the bottom plate.

In yet another possible implementation, the second circuit board is a circuit board with an aluminum nitride ceramic substrate.

In another possible implementation, the charging circuit includes: a charging resistor and a filter capacitor, the preset power supply is grounded through the filter capacitor, the preset power supply is also connected to one end of the charging resistor, one end of the charging resistor is the input end of the charging circuit, and the other end of the charging resistor is the output end of the charging circuit.

In yet another possible implementation, the charging resistor is a plurality of resistors connected in parallel.

In another possible implementation, the discharge circuit includes: an energy storage capacitor, one end of which is connected to the output end of the charging circuit, the other end of which is grounded, and one end of which is also connected to the anode of the semiconductor laser.

In a third aspect, an embodiment of the present application further provides a laser radar transmitting module, comprising a driving circuit as described in any one of the second aspects above, and further comprising: an optical element arranged on the light output side of a semiconductor laser.

The beneficial effects of this application are:

In the circuit structure, semiconductor laser driving circuit and laser radar transmitting module provided in the present application, The charging circuit and the discharging circuit in the circuit structure cooperate with each other to meet the pulse current requirements of the semiconductor laser, and realize the high peak power and narrow pulse width of the semiconductor laser. In addition, by setting the charging circuit in the circuit structure on the first circuit board and setting the discharging circuit in the circuit structure on the second circuit board, the charging circuit and the discharging circuit, which are the main heat power consumption in the circuit structure, are separated, and the conduction of heat generated by the charging circuit to the discharging circuit is limited, thereby limiting the heat conduction to the semiconductor laser, avoiding the temperature increase in the area where the semiconductor laser is located as much as possible, avoiding the problem of insufficient reliability of the semiconductor laser caused by the influence of high temperature, and realizing high reliability and high stability of the semiconductor laser.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of a circuit structure provided in an embodiment of the present application;

FIG2 is a schematic diagram of the structure of a driving circuit of a semiconductor laser provided in an embodiment of the present application;

FIG3 is a schematic diagram of the structure of another semiconductor laser driving circuit provided in an embodiment of the present application;

FIG4 is a schematic diagram of the structure of another semiconductor laser driving circuit provided in an embodiment of the present application;

FIG5 is a schematic diagram of a laser radar transmitting module provided in an embodiment of the present application;

FIG6 is a schematic diagram of a laser radar system provided in an embodiment of the present application.

icon:

11-charging circuit; 12-discharging circuit; 13-semiconductor laser; 14-switch unit; 15-signal processing circuit; A-first circuit board; B-second circuit board; 16-flexible cable; 17-temperature control unit; 18-optical element; R1-charging resistor; C1-filter capacitor; C2-energy storage capacitor; L1-inductor; V1-drive chip; Q1-switch tube; 51-drive circuit; 60-laser radar system; 61-laser radar transmitting module; 62-laser radar receiving module.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings 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.

It should be noted that the terms "including" and "having" and any variations thereof in the various parts of the embodiments of the present application and the drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device including a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include steps or units that are not clearly listed or are not intended to be included in the description. Other steps or elements inherent to such processes, methods, products or apparatuses.

The circuit structure, semiconductor laser driving circuit and laser radar transmitting module provided in the following embodiments of the present application are mainly aimed at high-power semiconductor lasers, such as 905nm semiconductor lasers. The circuit structure provided in the present application can reduce the influence of the thermal power consumption of the driving circuit on the performance of the semiconductor laser while providing the semiconductor laser with a high pulse current, that is, a pulse current with a large current and a narrow pulse width, so that the laser pulse energy of the semiconductor laser is well controlled. The circuit structure provided in the embodiments of the present application is first explained as an example in combination with multiple embodiments.

Fig. 1 is a schematic diagram of a circuit structure provided in an embodiment of the present application. As shown in Fig. 1 , the circuit structure includes: a charging circuit 11 and a discharging circuit 12.

The input end of the charging circuit 11 is connected to a preset power supply, and the output end of the charging circuit is connected to the discharge circuit 12. The discharge circuit 12 is also connected to the anode of the semiconductor laser 13, and the cathode of the semiconductor laser 13 is grounded. The charging circuit 11 is arranged on the first circuit board A, and the discharge circuit 12, the semiconductor laser 13, the switch unit 14 and the signal processing circuit 15 are arranged on the second circuit board B.

In this embodiment, the semiconductor laser 13 can also be called a laser chip, a laser diode (laser diode, LD) chip, for example, it can be an edge emitting laser diode (Edge Emitting Laser-laser diode, EEL-LD), also known as an edge emitting laser (Edge Emitting Laser, EEL).

The circuit structure is actually a charging and discharging circuit or a power supply of the semiconductor laser 13. The preset power supply can charge the energy storage unit in the discharge circuit 12 through the charging circuit 11, and then discharge to the anode of the semiconductor laser 13 through the discharge circuit 12, so as to provide a pulse current to the anode of the semiconductor laser 13, thereby realizing power supply to the semiconductor laser 13.

As the main heat load in the circuit structure, the heat power consumption generated by the charging circuit 11 is far greater than the heat power consumption generated by the discharge circuit and other circuits. In order to prevent the heat conduction of this part of the heat power consumption generated by the charging circuit 11 from affecting the area where the semiconductor laser 13 is located, in the solution provided in this embodiment, the charging circuit 11 and the discharge circuit 12 can be decoupled, and the charging circuit 11 and other parts (discharge circuit 12, semiconductor laser 13, etc.) can be respectively arranged on two different circuit boards to limit the heat conduction between the charging circuit 11 and other parts, thereby limiting the heat conduction of the heat power consumption generated by the charging circuit 11 to the area where the semiconductor laser 13 is located.

In a possible implementation example, the first circuit board A and the second circuit board B may be two circuit boards separated in physical space. The charging circuit and the discharging circuit are electrically connected via a flexible wire. The flexible wire may also be called a soft flat cable.

In the solution provided by this embodiment, the pulse current requirement of the semiconductor laser is met by the cooperation between the charging circuit and the discharging circuit in the circuit structure, and the high peak power and narrow pulse width of the semiconductor laser are achieved. The charging circuit in the circuit structure is also arranged on the first circuit board, and the discharging circuit in the circuit structure is arranged on the second circuit board where the semiconductor laser is located, so that the charging circuit with the main heat power consumption in the circuit structure and other circuit structures such as the discharging circuit are realized. The separate setting of the electrical circuit and the semiconductor laser limits the conduction of heat generated by the charging circuit to the discharge circuit, thereby limiting the heat conduction to the semiconductor laser, avoiding the temperature rise in the area where the semiconductor laser is located as much as possible, avoiding the problem of insufficient reliability of the semiconductor laser caused by high temperature, and achieving high reliability and high stability of the semiconductor laser.

The embodiment of the present application continues to explain the driving circuit of the semiconductor laser provided in conjunction with multiple drawings. FIG2 is a schematic diagram of the structure of a driving circuit of a semiconductor laser provided in the embodiment of the present application. As shown in FIG2, the driving circuit of the semiconductor laser includes: the circuit structure provided in the above embodiment, that is, the charging circuit 11 and the discharging circuit 12. On this basis, it may also include: a semiconductor laser 13, a switch unit 14 and a signal processing circuit 15.

The input end of the signal processing circuit 15 is used to receive a preset pulse signal, and the output end of the signal processing circuit is connected to the control end of the switch unit 14; the input end of the switch unit 14 is connected to the cathode of the semiconductor laser 13, and the output end of the switch unit 14 is grounded. The input end of the charging circuit 11 is connected to a preset power supply, and the output end of the charging circuit is connected to the discharge circuit 12. The discharge circuit 12 is also connected to the anode of the semiconductor laser 13 to supply power to the anode of the semiconductor laser 13.

The charging circuit 11 is arranged on the first circuit board A, and the discharging circuit 12 , the semiconductor laser 13 , the switching unit 14 and the signal processing circuit 15 are arranged on the second circuit board B.

The preset power supply can provide pulse current to the anode of the semiconductor laser 13 through the charging and discharging of the charging circuit 11 and the discharging circuit 12, and the cathode of the semiconductor laser 13 is grounded. Therefore, the charging of the charging circuit 11 and the discharging of the discharging circuit 12 are both controlled by the on-off of the switch unit 14 set between the cathode of the semiconductor laser 13 and the ground.

Specifically, if the switch unit 14 is in the non-conducting state, the path between the cathode of the semiconductor laser 13 and the ground is disconnected, and at this time, the preset power supply can charge the energy storage unit in the discharge circuit 12 through the charging circuit 11. Correspondingly, if the switch unit 14 is in the conducting state, the path between the cathode of the semiconductor laser 13 and the ground is connected, and at this time, the discharge circuit 12 can discharge to the anode of the semiconductor laser 13.

As for the on/off state of the switch unit 14 , the signal processing circuit 15 may control the switch unit 14 based on the input preset pulse signal.

Since the opening speed of the charging circuit 11 depends on the on-off state of the switch unit 14, the switching frequency of the switch unit 14 is 10KHz-100KHz, when the frequency of the switch unit 14 is the maximum value (100KHz), the corresponding charging time of the charging circuit 11 is about 10us; the opening state of the discharge circuit 12 depends on the on-off state of the switch unit 14, and the opening rate of the discharge circuit 12 depends on the opening time of the switch unit 14. The opening time of the switch unit 14 is approximately equal to 1ns, and the frequency corresponding to this opening time is 1GHz. The total time required for the discharge circuit 12 to discharge is approximately equal to 5ns, and the corresponding frequency at this time is 200MHz; so the charging circuit 11 can also be called a low-speed circuit or a low-speed loop (10KHz-100KHz); correspondingly, the discharge circuit 12 can also be called a high-speed circuit or a high-speed loop (200MHz-1GHz).

In the process of the preset power supply supplying power to the anode of the semiconductor laser 13, the charging circuit 11 is the main heat load in the driving circuit, and the heat generated by it may reach 90% of the heat generated by the entire driving circuit. For example, its peak power needs to be greater than or equal to 800W. To achieve a peak power of 800W, since the electro-optical conversion efficiency of a 905nm semiconductor laser is about 3.5W/A, the drive circuit needs to provide a pulse current of 228.6A to the anode of the semiconductor laser. Assuming that the switching frequency f of the switch unit is equal to 100KHz and the peak power is 800W, to provide a pulse current of 228.6A, the power consumption of the charging circuit 11 in the drive circuit accounts for 90%, which is about 7W, while the heat power consumption generated by other parts of the drive circuit accounts for about 10%, which is close to 0.77W. In order to avoid the influence of the main heat load in the driving circuit, that is, the heat power consumption generated by the charging circuit 11, on the area where the semiconductor laser 13 is located, in the solution provided in this embodiment, in addition to decoupling the charging circuit 11 and the discharging circuit 12 in the driving circuit, the charging circuit 11 and the discharging circuit 12 are separated, and the charging circuit 11 and the discharging circuit 12 are respectively arranged on two circuit boards, thereby limiting the heat conduction between the charging circuit 11 and other parts.

In the driving circuit of the semiconductor laser provided in this embodiment, the pulse current requirement of the semiconductor laser can be met by the cooperation between the charging circuit and the discharging circuit in the driving circuit, thereby achieving high peak power and narrow pulse width of the semiconductor laser. The charging circuit in the driving circuit can be arranged on a first circuit board, while the discharging circuit, the semiconductor laser, the switching unit and the signal processing circuit in the driving circuit can be arranged on a second circuit board, thereby achieving the separate arrangement of the charging circuit and other units of the driving circuit, which are the main heat consumption units, and limiting the heat generated by the charging circuit from being transferred to the semiconductor laser, thereby avoiding as much as possible the temperature increase in the area where the semiconductor laser is located, avoiding the problem of insufficient reliability of the semiconductor laser due to the influence of high temperature, and achieving high reliability and high stability of the semiconductor laser.

It should be noted that, in one example, the first circuit board A and the second circuit board B may be two different circuit boards in the same physical space. For example, they may be two different circuit boards in the shell of a laser radar transmitting module.

In another example, the first circuit board A and the second circuit board B may be two circuit boards separated in physical space, that is, the first circuit board A may be a circuit board arranged outside the shell of the laser radar transmitting module, and the second circuit board B may be a circuit board arranged inside the shell of the laser radar transmitting module, which may be a driving circuit board inside the shell of the laser radar transmitting module.

The specific arrangement of the circuit board is explained below in conjunction with the accompanying drawings. FIG3 is a schematic diagram of the structure of another semiconductor laser driving circuit provided in an embodiment of the present application. As shown in FIG3, the first circuit board A and the second circuit board B shown above are two circuit boards arranged outside and inside the shell of the laser radar transmitting module, respectively.

In a specific implementation, assuming that the switching frequency f of the switch unit is equal to 100KHz and the peak power is 800W, then to provide a pulse current of 228.6A, the thermal power consumption of the charging circuit 11 is about 7W, and the volume of a single resistor in the charging circuit that meets the 7W power consumption is very large. In the embodiment of the present application, it is separated from the laser radar transmitting module and arranged on the first circuit board A outside the shell of the laser radar transmitting module, which can greatly reduce the volume of the laser radar transmitting module. When the laser radar transmitting module is in a limited space in the shell, the components on the second circuit board can be arranged more flexibly.

In the scheme of this embodiment, the main heat load in the driving circuit, that is, the charging circuit, can be set on a circuit board outside the shell of the laser radar transmitting module, while the other parts of the driving circuit can be set on the circuit board inside the shell. This not only realizes the separate setting of the charging circuit and the semiconductor laser, reduces the impact of the thermal power consumption of the charging circuit on the area where the semiconductor laser is located, but also reduces the volume of the laser radar transmitting module.

3 , the components on the first circuit board A can be connected to the corresponding components on the second circuit board B via a flexible flat cable 16, also known as a flexible wire. In other words, the charging circuit 11 on the first circuit board A can be connected to the discharging circuit 12 on the second circuit board B via the flexible flat cable 16.

It should be pointed out that, in order to realize the electrical connection between the components on the first circuit board A and the second circuit board B, in addition to the flexible flat cable 16, other forms of connecting wires may also be used, and this embodiment should not be limited thereto.

By using a flexible flat cable to connect the corresponding components on the first circuit board and the second circuit board, the layout of each circuit unit in the driving circuit can be more flexible, thereby effectively ensuring the volume of the laser radar transmitting module.

In a possible implementation example, referring to FIG. 3 , the driving circuit further includes a temperature control unit 17 and a bottom plate, wherein the temperature control unit 17 is disposed between the second circuit board B and the bottom plate. The temperature control unit 17 may be a temperature controller (TEC) or a temperature control chip. For example, the discharge circuit 12, the semiconductor laser 13, the switch unit 14, and the driving chip V1 may be disposed on a first surface of the second circuit board B, and the temperature control unit 17 is disposed between the second surface and the bottom plate, wherein the second surface is a surface of the second circuit board B that is away from the first surface.

The temperature control unit 17 can be used to perform overall temperature control on the discharge circuit 12, semiconductor laser 13, switch unit 14, and driver chip V1, etc., which are arranged on the second circuit board B, so that the operating temperature of the semiconductor laser does not change as much as possible with the change of the ambient temperature, thereby ensuring the working stability and reliability of the semiconductor laser. At the same time, the main heat load in the drive circuit, that is, the charging circuit, is placed on another circuit board, that is, the first circuit board. Therefore, it is easy to perform overall temperature control on the laser radar transmitting module. It is only necessary to perform overall temperature control on the second circuit board where the discharge circuit is located, and the heat power consumption of the discharge circuit is only 10% of the overall heat power consumption. Since the volume of the temperature control unit is determined by the heat load, the smaller the heat load, the smaller the volume of the required temperature control unit, and the lower the cost of the temperature control unit.

Therefore, the solution of this embodiment can effectively reduce the volume of the temperature control unit by setting a temperature control unit between the second circuit board and the base plate, thereby reducing the volume and cost of the entire laser radar transmitting module.

Continuing to refer to FIG. 3 , an optical element 18 is further provided in the housing of the laser radar transmitting module. The optical element 18 is arranged on the light emitting side of the semiconductor laser 13 .

In some possible implementation examples, the circuit board where the semiconductor laser 13 is located, that is, the second circuit board B, can be a circuit board with an aluminum nitride (AlN) ceramic substrate. The semiconductor laser 13 can be directly packaged on the second circuit board B. It should be noted that the embodiment of the present application does not limit the specific material of the first circuit board A, which can be aluminum nitride (AlN). The circuit board may be a ceramic substrate, or may be a circuit board made of other materials, such as a circuit board made of epoxy resin.

In the solution provided in this embodiment, for the circuit board where the semiconductor laser is located, that is, the second circuit board, a circuit board with an aluminum nitride ceramic substrate is used. Since the thermal conductivity of the aluminum nitride ceramic substrate is relatively high, it is convenient to dissipate heat on the second circuit board, thereby ensuring the stability of the wavelength, directivity and divergence angle of the semiconductor laser, and improving the high reliability and high stability of the emission module.

On the basis of the semiconductor laser driving circuit provided in any of the above embodiments, this embodiment also provides some other possible implementation examples of the semiconductor laser driving circuit in combination with the specific structure of each circuit unit in the driving circuit. Figure 4 is a schematic diagram of the structure of another semiconductor laser driving circuit provided in an embodiment of the present application. On the basis of any of the above embodiments, the charging circuit 11 includes: a charging resistor R1 and a filter capacitor C1. The preset power supply is grounded through the filter capacitor C1, and the preset power supply is also connected to one end of the charging resistor R1, one end of the charging resistor R1 is the input end of the charging circuit 11, and the other end of the charging resistor R1 is the output end of the charging circuit.

It should be noted that the charging resistor R1 in FIG. 4 is only used to characterize that it is a resistor unit, and does not limit the specific composition of the charging resistor R1 . It can be a single resistor, or a resistor unit formed by multiple resistors connected in series or in parallel, and this embodiment does not limit this.

In an exemplary implementation example, the charging resistor R1 may be a plurality of resistors connected in parallel, and the resistance value of each resistor may be less than or equal to a preset resistance, or the power consumption of each resistor may be less than or equal to a preset power consumption.

Continuing with the example of a 905nm semiconductor laser, to achieve a peak power of 800W, the charging resistor R1 can be a resistor unit with a power consumption of about 7W. In a specific implementation example, the 7W resistor unit can be realized by connecting multiple resistors with a power consumption of 0.5W in parallel. The volume of a single resistor that meets the power consumption of 7W is usually very large, while the volume of a single resistor with a power consumption of 0.5W is relatively small. Even if multiple small resistors are connected in parallel, the total volume is much smaller than that of a resistor with a power consumption of 7W.

Multiple resistors in parallel are used to implement the charging resistor R1 to meet the high peak power of the semiconductor laser. Compared with the implementation scheme of using independent charging alone, the volume of the charging resistor is reduced because the resistor with a smaller resistance value or lower power consumption is usually small, thereby reducing the volume of the driving circuit.

4 , the discharge circuit 12 includes: a storage capacitor C2 , one end of which is connected to the output end of the charging circuit 11 , the other end of which is grounded, and one end of which is also connected to the anode of the semiconductor laser 13 .

Similar to the above-mentioned charging resistor R1, the energy storage capacitor C2 in Figure 4 is only characterized as a capacitor unit, and the specific composition of the energy storage capacitor C2 is not limited. It can be a single capacitor or a capacitor unit formed by multiple capacitors connected in series or in parallel. This embodiment does not limit this.

Optionally, the discharge circuit 12 may further include: an inductor L1, one end of the energy storage capacitor C2 is connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the anode of the semiconductor laser 13. The inductor L1 and the energy storage capacitor C2 form an LC resonant circuit.

Optionally, referring to FIG. 4 , the signal processing circuit 15 includes a driving chip V1 , wherein the control end of the driving chip V1 is the input end of the signal processing circuit 15 , the output end of the driving chip V1 is the output end of the signal processing circuit 15 , and the input end of the driving chip V1 is grounded.

The driver chip V1 may be a driver chip matched by the switch unit 14. If the switch unit 14 includes a switch tube Q1, and the switch tube Q1 is a gallium nitride field effect transistor (GaN FET) Q1 shown in FIG. 4, then the driver chip V1 may be a gate driver. Taking the gallium nitride field effect transistor as an example, the control end of the switch unit 14 may be the gate of the gallium nitride field effect transistor, the input end of the switch unit 14 may be the drain of the gallium nitride field effect transistor, and the output end of the switch unit 14 may be the source of the gallium nitride field effect transistor. It should be noted that in actual applications, the switch unit 14 may also be other similar transistors, and the drive control of the switch unit 14 can be realized as long as the driver chip V1 matches it.

Based on the driving circuit of the semiconductor laser provided in any of the above embodiments, the embodiment of the present application may also provide a laser radar transmitting module. FIG5 is a schematic diagram of a laser radar transmitting module provided in an embodiment of the present application. As shown in FIG5, the laser radar transmitting module may include a driving circuit 51 of the semiconductor laser shown in any of the above embodiments, and an optical element 18 arranged on the light emitting side of the semiconductor laser.

It should be noted that the driving circuit 51 and the optical module arranged on the light output side of the semiconductor laser together form a laser radar transmitting module.

The present application embodiment also provides a laser radar system. Figure 6 is a schematic diagram of a laser radar system provided by the present application embodiment. As shown in Figure 6, the laser radar system 60 includes: the laser radar transmitting module 61 provided above, and the laser radar receiving module 62 matched therewith.

The laser radar system 60 provided in this embodiment can be applied to a vehicle-mounted system, as a vehicle-mounted laser radar, and can also be applied to a machine vision system, as an airborne radar system equipped on a robot or industrial equipment.

The laser radar transmitting module and laser radar system having any of the semiconductor laser driving circuits shown above can achieve the effects of the semiconductor laser driving circuit shown in any of the above embodiments. Please refer to the above for details, and the embodiments of this application will not elaborate on this.

The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

A circuit structure, characterized in that the circuit structure comprises: a charging circuit and a discharging circuit; the input end of the charging circuit is connected to a preset power supply, and the output end of the charging circuit is connected to the discharging circuit; the discharging circuit is also connected to an anode of a semiconductor laser, and the cathode of the semiconductor laser is grounded;

Wherein, the charging circuit is arranged on a first circuit board, and the discharging circuit and the semiconductor laser are arranged on a second circuit board.
The circuit structure according to claim 1, characterized in that the first circuit board and the second circuit board are two circuit boards separated in physical space;

The charging circuit and the discharging circuit are electrically connected via a flexible wire.
A driving circuit for a semiconductor laser, characterized in that it comprises: the circuit structure according to claim 1 or 2, and further comprises: a semiconductor laser, a switch unit and a signal processing circuit;

The input end of the signal processing circuit is used to receive a preset pulse signal, and the output end of the signal processing circuit is connected to the control end of the switch unit; the input end of the switch unit is connected to the cathode of the semiconductor laser, and the output end of the switch unit is grounded;

The input end of the charging circuit in the circuit structure is connected to a preset power supply, the output end of the charging circuit is connected to the discharge circuit, and the discharge circuit in the circuit structure is also connected to the anode of the semiconductor laser to supply power to the anode of the semiconductor laser;

The charging circuit is arranged on a first circuit board, and the discharging circuit, the semiconductor laser, the switch unit and the signal processing circuit are arranged on a second circuit board.
The driving circuit according to claim 3 is characterized in that the first circuit board is arranged outside the shell of the laser radar transmitting module, and the second circuit board is arranged inside the shell of the laser radar transmitting module.
The driving circuit according to claim 3 is characterized in that the driving circuit further comprises: a temperature control unit and a bottom plate, and the temperature control unit is arranged between the second circuit board and the bottom plate.
The driving circuit according to claim 3 is characterized in that the second circuit board is a circuit board with an aluminum nitride ceramic substrate.
The driving circuit according to claim 3 is characterized in that the charging circuit comprises: a charging resistor and a filter capacitor, the preset power supply is grounded through the filter capacitor, the preset power supply is also connected to one end of the charging resistor, one end of the charging resistor is the input end of the charging circuit, and the other end of the charging resistor is the output end of the charging circuit.
The driving circuit according to claim 7, characterized in that the charging resistor is a plurality of resistors connected in parallel.
The driving circuit according to claim 3, characterized in that the discharge circuit comprises: an energy storage capacitor, One end of the energy storage capacitor is connected to the output end of the charging circuit, the other end of the energy storage capacitor is grounded, and one end of the energy storage capacitor is also connected to the anode of the semiconductor laser.
A laser radar transmitting module, characterized in that it includes the driving circuit described in any one of claims 3 to 9, and also includes: an optical element arranged on the light output side of the semiconductor laser.