CN117039610B

CN117039610B - Laser driving circuit and driving method, lighting system and laser radar

Info

Publication number: CN117039610B
Application number: CN202311302565.0A
Authority: CN
Inventors: 肖岩; 杨强强
Original assignee: Shenzhen Lemon Photon Technology Co ltd
Current assignee: Shenzhen Lemon Photon Technology Co ltd
Priority date: 2023-10-10
Filing date: 2023-10-10
Publication date: 2024-01-16
Anticipated expiration: 2043-10-10
Also published as: CN117767108A; CN117039610A

Abstract

The embodiment of the specification provides a laser driving circuit and a driving method, an illumination system and a laser radar, wherein the laser driving circuit is coupled with a laser module, the laser module comprises a plurality of lasers, cathodes of the lasers are connected with each other and grounded, and the laser driving circuit comprises: the sampling unit is coupled with the anode of each laser and is suitable for acquiring the working impedance of each laser in the light emitting process to obtain a corresponding impedance sampling signal; the control unit is suitable for receiving the impedance sampling signal, and generating a driving control signal corresponding to the working impedance according to the working impedance corresponding to the impedance sampling signal and the preset mapping relation between the impedance and the driving voltage; and the driving unit is suitable for responding to the driving control signal and generating a driving signal corresponding to the working impedance so as to adjust the light emitting parameters of the corresponding lasers. By adopting the technical scheme, the luminous consistency of the laser can be improved.

Description

Laser driving circuit and driving method, lighting system and laser radar

Technical Field

The embodiment of the specification relates to the technical field of laser driving control, in particular to a laser driving circuit, a driving method, a lighting system and a laser radar.

Background

Lasers are one of the essential core components in modern laser processing systems, and with the continued development of laser technology, semiconductor lasers have emerged. The semiconductor laser has obvious technical advantages, such as small volume, light weight, high efficiency, low energy consumption, long service life and the like, and is widely applied to the fields of optical fiber communication, optical fiber sensing, laser material processing and the like.

The laser modules may include a common anode laser and a common cathode laser based on different connection relationships. The common cathode laser module cannot be driven by the same constant current source, the common practice is that a single constant voltage source drives a single-path laser, and when the common cathode laser module is applied to multiple paths of lasers, the light emission consistency difference of the lasers is large.

In this context, how to improve the light emission uniformity of the laser is a technical problem that needs to be solved by those skilled in the art.

Disclosure of Invention

In view of this, the embodiments of the present disclosure provide a laser driving circuit and driving method, an illumination system, and a laser radar, which can improve the light emission uniformity of a laser.

In a first aspect, embodiments of the present disclosure provide a laser driving circuit coupled to a laser module, the laser module including a plurality of lasers, a cathode of each of the lasers being connected to a ground, wherein the laser driving circuit includes:

The sampling unit is coupled with the anode of each laser and is suitable for acquiring the working impedance of each laser in the light emitting process to obtain a corresponding impedance sampling signal;

the control unit is suitable for receiving the impedance sampling signal and generating a driving control signal corresponding to the working impedance according to the working impedance corresponding to the impedance sampling signal and the mapping relation between the preset impedance and the driving voltage;

and the driving unit is respectively coupled with the anode of each laser and the control unit and is suitable for responding to the driving control signals and generating driving signals corresponding to the working impedance so as to adjust the light emitting parameters of the corresponding lasers.

According to the laser driving circuit in the embodiment, according to the working impedance of each laser in the light emitting process, the same driving unit can provide driving signals corresponding to the working impedance for each laser, so that each laser can work under proper electric parameters, and the light emitting consistency of the lasers can be improved.

Optionally, the sampling unit includes: a plurality of first sampling resistors, a plurality of second sampling resistors, a plurality of gating modules, and a plurality of sampling modules, wherein:

A first sampling resistor corresponds to a gating module, a first end of the first sampling resistor is coupled with a first power end, and a second end of the first sampling resistor is coupled with a first end of the gating module;

a gating module corresponds to a laser and a sampling module, and a second end of the gating module is respectively coupled with anodes of the sampling module and the laser; the gating module is suitable for conducting the paths of the laser coupled with the gating module and the first power supply end when being gated;

the sampling module corresponds to a second sampling resistor, is coupled with the first end of the second sampling resistor, and is suitable for acquiring working impedance in the corresponding laser light emitting process and outputting the impedance sampling signal when the gating module is gated;

the second end of the second sampling resistor is grounded.

In the above embodiment, one sampling module may be used to collect the working impedance of a corresponding laser, so that the accuracy of the obtained impedance sampling signal may be improved, and the light emission consistency of each laser may be further improved.

Optionally, the sampling module includes an operational amplifier, a first input end of the operational amplifier is coupled to the second end of the gating module and the anode of the laser, a second input end of the operational amplifier is coupled to the first end of the second sampling resistor, and an output end of the operational amplifier is coupled to the control unit and is adapted to output the impedance sampling signal.

In the embodiment, the implementation mode of the sampling module is simpler. Optionally, the laser driving circuit further includes: the logic operation unit is respectively coupled with each sampling module and the control unit and is suitable for executing logic operation on the impedance sampling signals output by each sampling module to obtain a logic operation result;

the control unit is further adapted to update a mapping relationship between preset impedance and driving voltage according to the logic operation result and the driving signal corresponding to the impedance sampling signal.

In the above embodiment, by making each sampling module share the same logic operation unit, logic operation can be performed on the impedance sampling signal output by each sampling module, so that the sampling result of each sampling module can be input to the control unit successively, so that only one receiving port of the control unit is required to be occupied, too many connection ports are not required to be occupied, and the circuit structure can be simplified.

Optionally, the laser driving circuit further includes: the light intensity detection unit is coupled with the control unit and is suitable for detecting the luminous power of each laser and generating a corresponding light intensity detection signal to the control unit;

and the control unit is further adapted to output a sampling control signal to the sampling unit to gate the gating module corresponding to the light intensity detection signal when the light intensity detection signal contains light emitting power lower than the set light emitting power, wherein the impedance value of the laser corresponding to the gating module in the on state is used as the current working impedance value.

In the above embodiment, through the cooperation setting of the light intensity detection unit and the control unit, only the working impedance of the laser with the luminous power lower than the set luminous power needs to be collected, that is, only the luminous parameter with the luminous power lower than the set luminous power needs to be adjusted, the impedance value of the laser with the normal luminous power does not need to be collected, and the point-to-point accurate collection of the impedance value is realized, so that the driving efficiency can be improved.

Optionally, the driving unit includes: the device comprises a driving module, a comparing module, a switching module and a feedback module, wherein:

the driving module is coupled with the control unit, the comparison module and the feedback module respectively and is suitable for responding to the driving control signal to generate a driving signal corresponding to the working impedance; and an electrical parameter adapted to adjust the drive signal according to a feedback signal, wherein the electrical parameter of the drive signal comprises a voltage value and a current value of the drive signal;

the comparison module is coupled with the switch module and is suitable for outputting corresponding conduction signals according to the driving signals and the externally connected input voltage;

the switch module is coupled with the laser module and the control unit and is suitable for responding to the conducting signal and the switch signal from the control unit to output the driving signal to the laser module;

The feedback module is suitable for collecting the electrical parameters of the driving signals, and outputting the feedback signals for adjusting the electrical parameters of the driving signals to the driving module when the parameters of the driving signals are determined to not meet the preset electrical parameters.

In the adjusting process of the above embodiment, the feedback module may collect the electrical parameter of the driving signal, and output the feedback signal for adjusting the electrical parameter of the driving signal to the driving module when it is determined that the parameter of the driving signal does not meet the preset electrical parameter, so that the driving module can adjust the electrical parameter of the driving signal according to the feedback signal, so as to improve the accuracy of the obtained driving signal.

Optionally, the feedback module includes: a first voltage comparator, a current comparator, and a second voltage comparator, wherein:

the first input end of the second voltage comparator is respectively coupled with the first input ends of the switch module and the current comparator, the second input end of the second voltage comparator is respectively coupled with the switch module and the ground, and the output end of the second voltage comparator is coupled with the driving module and is suitable for collecting the voltage value of the driving signal;

the first input end of the first voltage comparator is coupled with the second power end, the second end of the first voltage comparator is coupled with the first input end of the current comparator, the output end of the first voltage comparator is coupled with the driving module, and the first voltage comparator is suitable for collecting an input voltage value provided by the second power end and outputting a corresponding voltage comparison signal to the driving module according to the voltage value of the driving signal collected by the second voltage comparator;

The first input end of the current comparator is respectively coupled with the switch module and the second voltage comparator, the output end of the current comparator is coupled with the driving module, and the current comparator is suitable for outputting corresponding current comparison signals to the driving module according to the acquired relation between the current value of the driving signal and a preset current value.

Optionally, the switching module includes a first transistor, a second transistor, and a third transistor, and the first transistor and the second transistor are different;

the control end of the first transistor is coupled with the comparison module, the input end of the first transistor is coupled with the second power supply end, and the output end of the first transistor is coupled with the input end of the second transistor, the input end of the third transistor and the first input end of the current comparator respectively;

the control end of the second transistor is coupled with the comparison module, and the output end of the second transistor is respectively coupled with the second input end of the second voltage comparator and the ground;

the control end of the third transistor is coupled with the control unit, and the input end of the third transistor is coupled with the laser module.

Optionally, the laser driving circuit further includes:

and the voltage protection unit is coupled with the driving unit and is suitable for carrying out voltage division processing on the voltage provided by the second power supply end when the difference value between the voltage provided by the accessed second power supply end and the set first reference voltage meets the preset voltage threshold value, obtaining divided voltage and outputting the divided voltage to the driving unit so that the driving unit outputs a corresponding driving signal to the anode of the corresponding laser.

In the above embodiment, when it is determined that the difference between the voltage provided by the accessed second power supply terminal and the set first reference voltage meets the preset voltage threshold, the voltage protection unit performs voltage division processing on the voltage provided by the second power supply terminal to obtain a divided voltage, and outputs the divided voltage to the driving unit, so that the driving unit can output a corresponding driving signal to the anode of the corresponding laser, and the driving unit is prevented from being damaged due to the fact that the voltage provided by the second power supply terminal is larger, thereby improving the operation stability of the laser driving circuit.

Optionally, the voltage protection unit includes: error amplifier, voltage dividing module and first resistance, wherein:

the first input end of the error amplifier is suitable for inputting the voltage provided by the second power end, the second input end of the error amplifier is connected with the first reference voltage, the third input end of the error amplifier is grounded through the first resistor, and the output end of the error amplifier is coupled with the first end of the voltage dividing module;

the second end of the voltage dividing module is coupled with the driving unit.

Optionally, the laser driving circuit further includes: the voltage conversion unit is coupled between the voltage protection unit and the driving unit, and is suitable for converting the divided voltage to obtain a converted voltage and outputting the converted voltage to the driving unit.

Optionally, the voltage conversion unit includes: a pulse amplifier and a capacitor, wherein:

the first input end of the pulse amplifier is respectively coupled with the voltage protection unit and the first end of the capacitor, the second end of the pulse amplifier is connected with a set second reference voltage, and the output end of the pulse amplifier is coupled with the driving unit;

the second end of the capacitor is grounded.

In the above embodiment, the voltage conversion unit is configured to convert the divided voltage to obtain a converted voltage suitable for the operation of the driving unit, so as to further improve the operation stability of the laser driving circuit.

Optionally, the laser driving circuit further includes: and the configuration unit is coupled with the control unit and is suitable for carrying out functional configuration on the control unit based on the configuration data so as to determine the light emitting parameters of the laser to emit light in a light emitting mode.

In the above embodiment, by setting the configuration unit, the laser driving circuit can be adapted to different working modes, so as to improve universality of the laser driving circuit.

In a second aspect, embodiments of the present disclosure further provide an illumination system, including:

the laser module is suitable for providing illumination light and comprises a plurality of lasers, and cathodes of the lasers are connected with each other and grounded;

The laser driving circuit of any of the above embodiments, coupled to the anode of each laser, adapted to provide driving signals to each laser to adjust the emission parameters of the corresponding laser.

In the lighting system, the application of the laser driving circuit enables the light emission consistency of the system to be stronger, so that the lighting effect is greatly improved.

In a third aspect, an embodiment of the present disclosure further provides a laser radar, including a laser module, an optical system, an echo detection device, and a computing system, where the laser driving circuit in any one of the foregoing embodiments is:

the laser module comprises a plurality of lasers, wherein cathodes of the lasers are connected with each other and grounded, and the laser module is suitable for providing detection light;

the laser driving circuit is coupled with the anode of each laser and is suitable for driving the lasers in the laser module to emit light;

the optical system is suitable for transmitting the detection light to a detection target object and transmitting the reflected light of the detection target object to the echo detection device;

the echo detection device is suitable for acquiring the receiving time of the reflected light;

the computing system is suitable for computing the distance of the detection target object according to the emission time of the detection light and the receiving time of the reflected light.

In the laser radar, the laser driving circuit is applied to ensure that the system has stronger luminous consistency, and is favorable for ensuring the consistency of the laser array operation during the laser radar detection, thereby better improving the laser detection precision.

In a fourth aspect, embodiments of the present disclosure further provide a laser radar laser driving method for adjusting a light emitting parameter of a corresponding laser in a laser module, where a cathode of each laser is connected to a ground, the laser driving method includes:

acquiring the working impedance of each laser in the light emitting process, and acquiring a corresponding impedance sampling signal;

generating a driving control signal corresponding to the working impedance according to the working impedance corresponding to the impedance sampling signal and a preset mapping relation between the impedance and the driving voltage;

and generating a driving signal corresponding to the working impedance in response to the driving control signal so as to adjust the light emitting parameters of the corresponding lasers.

According to the method, according to the working impedance of each laser in the light emitting process, the same driving unit can provide driving signals corresponding to the working impedance for each laser, so that each laser can work under proper electric parameters, and the light emitting consistency of the lasers can be improved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present application, and that other drawings may be obtained according to the provided drawings without inventive effort to a person skilled in the art.

FIG. 1 is a schematic diagram of a common anode laser module;

fig. 2 is a schematic structural diagram of a laser driving circuit according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of a sampling unit according to an example of the present disclosure;

fig. 4 is a schematic structural view of a driving unit in the example of the present specification;

FIG. 5 is a schematic diagram of another laser driving circuit according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of an illumination system according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of a lidar according to an embodiment of the present disclosure;

fig. 8 is a flowchart of a laser driving method according to an embodiment of the present disclosure.

Detailed Description

As described in the background art, when the same constant current source is applied to a plurality of lasers, the light emission uniformity of each laser is greatly different.

In order to solve the above technical problems, the embodiments of the present disclosure provide a laser driving circuit, which may be coupled to a laser module, where the laser module includes a plurality of lasers, and cathodes of the lasers are connected to a ground, where the laser driving circuit may include a sampling unit, a control unit, and a driving unit, where the sampling unit may obtain working impedance of each laser in a light emitting process to obtain a corresponding impedance sampling signal, and the control unit may generate a driving control signal corresponding to the working impedance according to the working impedance corresponding to the impedance sampling signal and a mapping relationship between preset impedance and driving voltage, so that the driving unit may generate a driving signal corresponding to the working impedance in response to the driving control signal to adjust a light emitting parameter of the corresponding laser. Therefore, by adopting the laser driving circuit in the embodiment of the specification, according to the working impedance of each laser in the light emitting process, the same driving unit can provide driving signals corresponding to the working impedance for each laser, so that each laser can work under proper electric parameters, and the light emitting consistency of the lasers can be improved.

In order that those skilled in the art will better understand the driving mechanism, principles and advantages of the embodiments of the present disclosure, a detailed description will be made with reference to specific embodiments thereof.

Referring to a schematic structure of a laser module shown in fig. 1, as shown in fig. 1, a laser module 100 may include a plurality of lasers (e.g., lasers LD1 to LDn).

As a specific example, multiple lasers in a laser module in this specification may be accessed to the laser driver circuit in a "common cathode" manner. Specifically, anodes of the n lasers are coupled to the same laser driving circuit, and cathodes of the n lasers may be grounded, where n is an integer greater than 1.

In some embodiments, lasers LD1 through LDn may be disposed on the same substrate B; in some other embodiments, the lasers LD1 to LDn may be provided on different substrates, which is not limited in any way in the embodiments of the present specification, as long as the laser driving circuit in the embodiments of the present specification is capable of driving each laser to emit light.

In practical applications, the laser driving circuit in the embodiments of the present disclosure may be coupled to the anode of each laser to drive each laser to emit light.

Specifically, referring to fig. 1, referring to a schematic structural diagram of a laser driving circuit in the embodiment of the present disclosure shown in fig. 2, in some embodiments of the present disclosure, a laser driving circuit 200 may be coupled to a laser module 100, as shown in fig. 1, the laser module 100 may include lasers LD1 to LDn, and the lasers LD1 to LDn are connected by a common cathode.

Accordingly, the laser driving circuit 200 may include: a sampling unit 210, a control unit 220, and a driving unit 230, wherein:

the sampling unit 210 is coupled with the anode of each laser and is suitable for acquiring the working impedance of each laser in the light emitting process to obtain a corresponding impedance sampling signal;

the control unit 220 is adapted to receive the impedance sampling signal, and generate a driving control signal corresponding to the working impedance according to the working impedance corresponding to the impedance sampling signal and a mapping relationship between a preset impedance and a driving voltage;

the driving unit 230 is coupled to the anode of each laser and the control unit, respectively, and is adapted to generate a driving signal corresponding to the operating impedance in response to the driving control signal, so as to adjust the light emitting parameters of the corresponding laser.

Referring to fig. 1 and 2, the sampling unit 210 may be coupled to anodes of the lasers LD1 to LDn, and may obtain an operating impedance of one of the lasers when the laser is in a light emitting state. For example, as shown in fig. 1, the laser LD7 emits light, and the sampling unit 210 may acquire the operating impedance R of the laser LD7 _LD7 And can output an impedance sampling signal R corresponding to the impedance sampling signal _C7 。

The control unit 220 may generate a driving control signal corresponding to the operating impedance according to the impedance sampling signal and a preset mapping relationship between the impedance and the driving voltage, and the driving unit 230 may generate a driving signal for adjusting the light emitting parameters of the corresponding laser in response to the driving control signal.

For example, the control unit 220 may sample the signal R according to the impedance _C7 And a mapping relation between preset impedance and driving voltage, and generating and working impedance R _LD7 The corresponding driving control signal TC7, and thus the driving unit, may adjust the light emitting parameter of the laser LD7 in response to the driving control signal TC 7.

In some embodiments of the present description, the lighting parameters may include lighting brightness, lighting timing, and lighting duration.

It will be appreciated that the specific types of lighting parameters described above are merely exemplary, and that the present embodiments are not limited in any way. For example, in some other embodiments, the lighting parameters may also include a lighting time.

As can be seen from the above, with the laser driving circuit according to the embodiments of the present disclosure, according to the working impedance of each laser in the light emitting process, the same driving unit can provide the driving signal corresponding to the working impedance for each laser, so that each laser can operate under appropriate electrical parameters, and the light emitting consistency of the lasers can be improved.

For better understanding and implementation by those skilled in the art, some examples of the realizations of the modules in the laser transmitter circuits of the present specification are shown below.

In some embodiments of the present disclosure, the lasers may not maintain good emission uniformity when operating with different lasers, even if the same driving voltage is provided, taking into account manufacturing process induced variations. In a specific implementation, to eliminate this difference, the embodiment of the present disclosure may compensate the driving signal according to the impedance feedback when the laser is in operation, which includes the following specific steps:

step 1, performing impedance detection, namely respectively acquiring actual impedance values of all lasers;

and 2, respectively adjusting the frequency and the duty ratio of the driving signals output to each laser, detecting the output actual current value in real time, and comparing the actual current value with a target driving current value, wherein the actual current value reaches the target driving current value or is in a target threshold range after at least one adjustment.

Wherein the target driving current value I ₀ The specific determination can be made according to the operating parameters of the laser to be driven, or the user can customize the laser; and "target threshold range" means that the target driving current value I is used ₀ A range set as a base reference, for example, a preset threshold floating interval of + -I ₁ Then the target threshold range is (I) ₀ - I ₁ ，I ₀ + I ₁ ）。

And 3, detecting the output voltage value of each laser when the actual current value reaches the target driving current value or is in the target threshold range, carrying out association matching setting on the output voltage value and the actual impedance value, and storing the output voltage value and the actual impedance value in a memory.

And 4, generating an impedance-voltage configuration table according to the matching condition of the voltage values of the lasers and the actual impedance values, and storing the impedance-voltage configuration table.

And 5, when driving each laser, the control unit can call the impedance-voltage configuration table from the storage table, and determine the voltage value matched with the actual impedance value of each laser according to the impedance-voltage configuration table and the actual impedance value of each laser, so that the driving unit can modulate a driving signal corresponding to the voltage value and output the driving signal to the corresponding laser.

In an ideal state, the actual current value of each laser reaches the target driving current value or is in the target threshold range, so that the light emission consistency of each laser can be ensured.

In some embodiments, an AI intelligent model can be introduced to learn and train the impedance-voltage configuration table under various modes and various application scenes, and the trained model can be directly applied to other laser driving circuits.

In particular implementations, the control unit may be implemented by a central processing unit (Central Processing Unit, CPU), field programmable gate array (Field Programmable Gate Array, FPGA), or the like, as well as by an integrated circuit (Application Specific Integrated Circuit, ASIC) or one or more integrated circuits configured to implement embodiments of the present invention.

In some embodiments of the present description, the sampling unit may include a plurality of first sampling resistors, a plurality of second sampling resistors, a plurality of gating modules, and a plurality of sampling modules, wherein:

the first sampling resistor corresponds to a gating module, a first end of the first sampling resistor is coupled with the first power end, and a second end of the first sampling resistor is coupled with the first end of the gating module;

the second end of the gating module is respectively coupled with the anodes of the sampling module and the laser; the gating module is suitable for conducting the path of the laser and the first power supply terminal which are coupled with the gating module when being gated;

the sampling module corresponds to a second sampling resistor, is coupled with the first end of the second sampling resistor, and is suitable for acquiring working impedance in the corresponding laser light emitting process and outputting an impedance sampling signal when the gating module is gated;

The second end of the second sampling resistor is grounded.

In short, the number of the first sampling resistor, the second sampling resistor, the gating module, and the sampling module in the embodiments of the present specification is the same and equal to the number of lasers. That is, in the embodiment of the present disclosure, one sampling module may be used to collect the working impedance of a corresponding laser, so that the accuracy of the obtained impedance sampling signal may be improved, and further the light emission consistency of each laser may be further improved.

As a specific example, as shown in a schematic structure of a sampling unit in fig. 3, in some embodiments of the present disclosure, in conjunction with fig. 1 to 3, the sampling unit 210 may include first sampling resistors R11 to R1n, second sampling resistors R21 to R2n, gating modules K1 to Kn, and sampling modules 211 to 21n.

For ease of understanding, the impedance of the laser LD1 sampled by the sampling module 211 is exemplified, and description of other sampling modules may be referred to in detail for the sampling module 211.

As shown in fig. 3, a first terminal of the first sampling resistor R11 may be connected to the first power supply terminal VCC1, and a second terminal thereof may be connected to a first terminal of the gating module K1; a second end of the gating module K1 may be connected to the sampling module 211 and an anode of the laser LD1, respectively, and the laser LD1 may emit light when the gating module K1 is gated; the first end of the second sampling resistor R21 is connected to the sampling module 211, and the second end thereof is grounded.

The principle of sampling the working impedance of the laser LD1 by the sampling module 211 is:

when the gating module K1 is gated, the first sampling resistor R11 and the laser LD11 are connected in series, and the current value flowing through the first sampling resistor R11 is the same as the current value flowing through the laser LD 11. Based on the principle of 'virtual short' of the operational amplifier, the voltages at the first input end and the second input end of the operational amplifier are the same, namely the voltage U of the second sampling resistor R21 _R21 The same voltage as the laser LD11 and the current flowing through the first sampling resistor R11 are: (U) _VCC1 - U _R21 ）/R _R11 。

Since the cathode of the laser LD11 is grounded, for the conducting branch formed by the first sampling resistor R11 and the laser LD11, the corresponding total impedance is: u (U) _VCC1 * R _R11 /（U _VCC1 - U _R21 ) Further, the impedance of the laser LD11 can be obtained as follows: u (U) _VCC1 *R11/（U _VCC1 - U _R21 ）- R _R11 。

It will be appreciated that the specific configuration of the sampling unit illustrated above is merely illustrative and is not intended to limit the specific configuration of the sampling unit, and that in implementations, other configurations of sampling circuits or devices may be used to obtain the operating impedance of the laser.

In specific implementation, the specific structure of each sampling module can be flexibly set according to actual requirements.

As a specific example, the sampling module in the embodiment of the present disclosure may include an operational amplifier, where a first input terminal of the operational amplifier is coupled to the second terminal of the gating module and an anode of the laser, respectively, a second input terminal of the operational amplifier is coupled to the first terminal of the second sampling resistor, and an output terminal of the operational amplifier may be coupled to the control unit and adapted to output an impedance sampling signal.

For example, with continued reference to fig. 3, the sampling module 211 may include an operational amplifier A1, a first input terminal of the operational amplifier A1 may be coupled to a second terminal of the gating module K1 and an anode of the laser LD1, respectively, a second input terminal thereof may be coupled to a first terminal of the second sampling resistor R21, and an output terminal thereof may be adapted to output an impedance sampling signal.

In the actual working process, only part of the lasers may emit light, and when the acquisition module acquires the working impedance of the corresponding lasers, the control unit can obtain a driving signal corresponding to the working impedance of the lasers according to the preset mapping relation between the impedance and the driving voltage. At this time, it is explained that when a driving signal is output to the laser, the laser can output laser light satisfying the light emission parameter, and therefore, the map between the impedance and the driving voltage set in advance can be updated.

As a specific example, the laser driving circuit in the embodiment of the present specification may further include: and the logic operation unit is respectively coupled with each sampling module and the control unit and is suitable for executing logic operation on the impedance sampling signals output by each sampling module to obtain a logic operation result.

Correspondingly, the control unit is further adapted to update a mapping relation between preset impedance and driving voltage according to the logic operation result and the driving signal corresponding to the impedance sampling signal.

For example, in conjunction with fig. 2 and 3, the laser driving circuit in the embodiment of the present specification may further include: the logic operation unit 240, the logic operation unit 240 may be coupled to the sampling modules 211 to 21n and the control unit 220, respectively, and perform logic operation on the impedance sampling signals output by the sampling modules 211 to 21n to obtain a logic operation result.

Specifically, when the sampling module outputs an impedance sampling signal, which corresponds to a high level "1", and the other sampling modules which do not output impedance sampling signals correspond to a low level "0", a corresponding logic operation result can be obtained through logic operation, and the logic operation result can represent the laser sampled at this time.

The control unit can determine that the impedance sampling signals obtained by sampling at this time comprise the impedance of the lasers according to the logic operation result, further can determine the driving signals corresponding to the impedance sampling signals, and uses the impedance corresponding to the impedance sampling signals acquired at this time and the voltage value corresponding to the driving signals as a new mapping relation, further can update the mapping relation between the impedance of at least one laser and the driving voltage.

For example, with continued reference to fig. 3, it is assumed that the sampling module 211 outputs a sampling impedance signal to the logic operation unit 240, and the other sampling modules do not output a sampling impedance signal to the logic operation unit 240, and then after logic operation, the control unit may determine that the current sampling is the impedance of the laser LD1, and then may reestablish the mapping relationship between the impedance and the voltage of the laser LD 1.

By adopting the mode in sequence, the new corresponding relation between the impedance and the voltage of any laser can be obtained, and the preset mapping relation between the impedance and the driving voltage can be updated.

In some embodiments of the present disclosure, the logic operation unit may include an OR logic gate OR, where the OR logic gate OR may perform an OR logic operation according to a new round of updating the impedance-voltage configuration table required by each laser in the laser module, so that the impedance values sampled by each sampling module may be sequentially output to the control unit.

It should be understood that the logic operation unit may also include a plurality of logic circuits, which is not limited in this embodiment of the present disclosure, as long as the logic operation can be performed on the impedance sampling signals output by the sampling modules, so that the logic operation result corresponds to each sampling module.

Therefore, each sampling module shares the same logic operation unit, so that the impedance sampling signals output by each sampling module can be subjected to logic operation, the sampling results of each sampling module can be sequentially input to the control unit, only one receiving port of the control unit is needed to be occupied, too many connecting ports are not needed to be occupied, and the circuit structure can be simplified.

As before, the laser module includes a plurality of lasers, and there may be some lasers whose light emission parameters already meet the light emission requirement, so that the light emission parameters of the resistors need not be adjusted, that is, the mapping relationship between the impedance and the driving voltage need not be updated.

As a specific example, the laser driving circuit in the embodiment of the present specification may further include: the light intensity detection unit is coupled with the control unit and is suitable for detecting the luminous power of each laser and generating corresponding light intensity detection signals to the control unit.

Correspondingly, the control unit is further adapted to output a sampling control signal to the sampling unit to gate the gating module corresponding to the light intensity detection signal when the light intensity detection signal contains light emitting power lower than the set light emitting power, wherein the impedance value of the laser corresponding to the gating module in the on state is used as the current working impedance value.

Specifically, when the lasers emit light, the light intensity detection unit may detect the light emitting power (may be considered as the light emitting brightness) of each laser, and the control unit may determine a relative relationship between the light emitting power and the set light emitting power of each laser, and when determining that the light emitting power of the laser is lower than the set light emitting power (indicating that the voltage output to the laser cannot make the laser be in the set working state), output at least one sampling control signal to the sampling unit, so as to conduct the gating module corresponding to the light intensity detection signal, and at this time, may take the impedance value of the laser corresponding to the gating module in the conducting state as the current working impedance value, and further may make at least one of the lasers emit light again according to the driving signal output by the driving unit according to the current working impedance value and the preset mapping relationship between the impedance and the driving voltage.

In some embodiments, the light intensity detection unit may include a photodiode PD, where the photodiode PD may convert an optical signal output by the laser into an electrical signal, and the control module may determine the light emitting power of each laser according to the electrical signal.

By adopting the mode, as the light intensity detection unit can detect the light emitting power of each laser, the control unit can output the sampling control signal to the sampling unit when determining that the light emitting power contained in the light intensity detection signal is lower than the set light emitting power, so as to gate the gating module corresponding to the light intensity detection signal, and further, only the working impedance of the laser with the light emitting power lower than the set light emitting power needs to be acquired, namely, only the light emitting parameter with the light emitting power lower than the set light emitting power needs to be adjusted, so that the driving efficiency can be improved.

By adopting the mode, the driving control signal corresponding to the laser light emitting state can be determined, and the driving unit can generate the driving signal for adjusting the laser light emitting parameter.

In some embodiments of the present disclosure, referring to fig. 1 to 3, and referring to a schematic structural diagram of a driving unit in the implementation of the present disclosure shown in fig. 4, the driving unit 230 may include: a driving module 231, a comparing module 232, a switching module 233 and a feedback module 234, wherein:

A driving module 231 coupled to the control unit 220, the comparing module 232 and the feedback module 234, respectively, adapted to generate a driving signal corresponding to the operating impedance in response to the driving control signal; and an electrical parameter adapted to adjust the drive signal according to the feedback signal, wherein the electrical parameter of the drive signal comprises a voltage value and a current value of the drive signal;

the comparison module 232 is coupled with the switch module 233 and is suitable for outputting a corresponding conduction signal according to the driving signal and the external input voltage;

a switch module 233 coupled to the laser module 100 (specifically, the anode of each laser) and the control unit 220, and adapted to respond to the on signal and the switch signal from the control unit 220 and output a driving signal to the laser module 100;

the feedback module 234 is adapted to collect electrical parameters of the driving signal and output a feedback signal for adjusting the electrical parameters of the driving signal to the driving module when it is determined that the parameters of the driving signal do not meet the preset electrical parameters.

Specifically, the driving module 231 is configured to generate a driving signal for adjusting a light emitting parameter of the laser in response to the driving control signal, under the action of the driving signal, the comparing module 232 is configured to turn on the switching module 233 and output the driving signal to the laser module 100, meanwhile, the feedback module 234 is configured to collect a voltage value and a current value of the driving signal, compare the voltage value and the current value of the driving signal with preset electrical parameters, and output a feedback signal for adjusting the electrical parameter of the driving signal to the driving module 231 when it is determined that the parameter of the driving signal does not meet the preset electrical parameter, and the driving module 231 is configured to adjust the electrical parameter of the driving signal according to the feedback signal and output the adjusted driving signal to an anode of a corresponding laser, so that the laser can emit laser light meeting the set light emitting parameter.

In some embodiments, with continued reference to fig. 4, the feedback module 234 may include: a first voltage comparator MC, a current comparator OC and a second voltage comparator RC, wherein:

the first input end of the second voltage comparator OC is respectively coupled with the first input ends of the switch module 233 and the current comparator OC, the second input end of the second voltage comparator OC is respectively coupled with the switch module 233 and the ground, and the output end of the second voltage comparator OC is coupled with the driving module 231 and is suitable for collecting the voltage value of the driving signal;

the first input end of the first voltage comparator MC is coupled to the second power supply end VIN, the second end thereof is coupled to the first input end of the current comparator OC, the output end thereof is coupled to the driving module 231, and is adapted to collect an input voltage value provided by the second power supply end VIN, and output a corresponding voltage comparison signal to the driving module 231 according to the voltage value of the driving signal collected by the second voltage comparator RC;

the first input end of the current comparator OC is coupled to the first input ends of the switch module 233 and the second voltage comparator RC, respectively, and the output end thereof is coupled to the driving module 231, and is adapted to output a corresponding current comparison signal to the driving module 231 according to the relation between the current value of the collected driving signal and the preset current value.

Specifically, the first voltage comparator MC may collect the voltage value provided by the second power supply terminal VIN, the second voltage comparator RC may collect the voltage value of the driving signal, and since the second input terminal of the first voltage comparator MC may be connected to the first input terminal of the second voltage comparator RC, the first voltage comparator MC may determine, according to the voltage value provided by the second power supply terminal VIN and the voltage value of the driving signal, whether the voltage value of the driving signal meets the set requirement, and when it is determined that the voltage value of the driving signal does not meet the set requirement, the first voltage comparator MC may output a voltage feedback signal to the driving module 231; meanwhile, the current comparator OC may collect a current value of the driving signal, and output a corresponding current comparison signal to the driving module 231 when it is determined that the current value of the driving signal is different from the preset current value.

The driving module 231 may further perform Pulse Width Modulation (PWM) on the driving signal according to the voltage feedback signal and the current feedback signal, so that the voltage value and the current value of the driving signal can meet the set requirement.

In some embodiments, with continued reference to fig. 4, the comparison module 232 may include a first comparator CP1 and a second comparator CP2, wherein:

The first comparator CP1 has a first end coupled to the driving module 231, a second end coupled to the second power supply terminal VIN, and a third end coupled to the third power supply terminal VCC2, and is adapted to output a high-level on signal when determining that the voltage value corresponding to the driving signal is greater than the voltage value provided by the third power supply terminal VCC 2; conversely, a conduction signal with a low level is output;

the first end of the second comparator CP2 is coupled to the driving module 231, the second end thereof is coupled to the fourth power supply terminal VCC3, and the third end thereof is coupled to the second input end of the second voltage comparator, and is adapted to output a high-level turn-on signal when determining that the voltage value corresponding to the driving signal is greater than the voltage value provided by the fourth power supply terminal VCC 3; conversely, a turn-on signal having a low level is output.

In some embodiments, with continued reference to fig. 4, the switch module 233 includes a first transistor M1, a second transistor M2, and a third transistor M3, and the first transistor M1 and the second transistor M2 are different;

the control terminal of the first transistor M1 is coupled to the comparing module 232 (specifically, the first comparator CP 1), the input terminal thereof is coupled to the second power supply terminal VIN, and the output terminal thereof is respectively coupled to the input terminal of the second transistor M2, the input terminal of the third transistor M3, and the first input terminal of the current comparator OC;

The control terminal of the second transistor M2 is coupled to the comparing module 232 (specifically, the second comparator CP 2), and the output terminal thereof is coupled to the second input terminal of the second voltage comparator RC and ground, respectively;

the control terminal of the third transistor M3 is coupled to the control unit 220, and the input terminal thereof is coupled to the laser module 100.

Specifically, since the first transistor M1 and the second transistor M2 are different, when the first comparator CP1 and the second comparator CP2 each output an on signal having a high level, only one of the first transistor M1 and the second transistor M2 may be turned on, for example, the first transistor M1 may be turned on, and thus a driving signal may be output to the input terminal of the third transistor M3, and when the control terminal of the third transistor M3 receives a control signal from the control unit 220, the third transistor M3 may be turned on, and thus each laser in the laser module 100 may emit light.

It should be noted that, the control signal in the embodiment of the present disclosure may be generated when the control unit obtains the impedance acquisition signal of the corresponding laser, that is, the control for controlling the third transistor to be turned on is also generated when the impedance acquisition signal of the laser is obtained.

In some embodiments, the first transistor M1 and the second transistor M2 may be turned on at the same time. For example, the first comparator CP1 outputs a turn-on signal having a high level can satisfy the turn-on requirement of the first transistor M1, and the second comparator CP2 outputs a turn-on signal having a low level can satisfy the turn-on requirement of the second transistor M2.

In practice, the inventors have found that when the voltage input to the driving unit exceeds the safe operating voltage range of the driving unit, the driving unit and the subsequent electronic components may be dangerous, and thus the voltage value input to the driving unit needs to be detected.

In some embodiments of the present specificationReferring to fig. 5, the laser driving circuit in the embodiment of the present disclosure further includes a voltage protection unit 250, where the voltage protection unit 250 may be coupled to the driving unit 230 and adapted to determine the voltage provided by the second power source terminal VIN and the set first reference voltage V _ref1 When the difference value satisfies the preset voltage threshold, the voltage provided by the second power supply terminal VIN is divided to obtain a divided voltage, and the divided voltage is output to the driving unit 230, so that the driving unit 230 outputs a corresponding driving signal to the anode of the corresponding laser.

Specifically, by comparing the relative relation between the voltage provided by the accessed second power supply end and the set first reference voltage, when the difference between the two voltages meets the preset voltage threshold value, the phenomenon that the voltage is overlarge at a certain moment due to the phenomena of too fast power-on, electrostatic discharge (ESD) and the like of the power supply voltage can be prevented, and the driving unit is in a safe working voltage.

In some embodiments, the drive unit may be powered in a soft start manner.

In an implementation, as shown in fig. 5, the voltage protection unit 250 may include: error amplifier EA, voltage dividing module 251 and first resistor R1, wherein:

the error amplifier EA has a first input terminal adapted to input a voltage provided by the second power supply terminal VIN and a second input terminal connected to the first reference voltage V _ref1 The third input end of the voltage divider is grounded through a first resistor R1, and the output end of the voltage divider is coupled with the first end of the voltage divider module 251;

a second end of the voltage dividing module 251 is coupled to a driving unit 230 (which may be a driving module 231 in particular).

In some embodiments, the voltage dividing module 251 may include a second resistor R2 and a third resistor R3, where a first end of the second resistor R2 is coupled to the output end of the error amplifier EA, and a second end thereof is connected to a first end of the third resistor R3 and the driving unit 230;

The second end of the third resistor R3 is grounded.

The operating principle of the voltage protection unit 250 is as follows:

error amplifier EA by comparison ofA voltage value of an input end and a first reference voltage V of a second input end _ref1 If the difference value of the voltage between the two is determined to be within the set range, the corresponding voltage value can be output, and after the voltage is divided by the second resistor R2 and the third resistor R3, a suitable voltage can be provided for the driving module 231.

In a specific implementation, since the set reference voltage of the error amplifier is small, if the divided voltage of the voltage protection unit is directly output to the driving unit, the driving signal output by the driving unit may not drive the laser to emit light normally.

Based on this, with continued reference to fig. 5, the laser driving circuit in the embodiment of the present disclosure further includes a voltage conversion unit 260, and the voltage conversion unit 260 may be coupled between the voltage protection unit 250 and the driving unit (e.g. the driving module 231) and adapted to convert the divided voltage to obtain a converted voltage, and output the divided voltage to the driving unit.

In some embodiments, the voltage conversion unit 260 includes: a pulse amplifier BA and a capacitor C1, wherein a first input end of the pulse amplifier is respectively coupled with the voltage protection unit 250 and a first end of the capacitor C1, and a second input end of the pulse amplifier is connected with a set second reference voltage V _ref2 The output end of which is coupled with the driving unit 230;

the second terminal of the capacitor C1 is grounded.

Specifically, the voltage obtained by dividing the second resistor R2 and the third resistor R3 is compared with the second reference voltage V _ref2 By comparing, the pulse amplifier BA can be ensured to output a voltage value satisfying the driving requirement, and even when the voltage provided by the second power supply terminal VIN is large, the driving unit can still operate normally.

In implementations, the emission parameters of the laser may be set to emit light patterns for different scenes and different operating parameters. For example, when the laser is applied to the illumination field, the power, brightness, illumination duration, dimming value (such as color temperature, color) of the laser can be set for different illumination environments (such as tunnel, open road surface, illuminated weather, etc.), and the combination of the illuminated lasers, for example, a plurality of lasers on the same array emit light, or a plurality of lasers on different arrays emit light, so that a plurality of illumination modes can be configured.

Similarly, different working modes can be correspondingly adapted for different application scenes in industrial processing, consumer electronics, vehicle-mounted and laser medical science.

Based on this, the laser driving circuit in the embodiment of the present specification may further include: and the configuration unit can be coupled with the control unit and is suitable for carrying out functional configuration on the control unit based on the configuration data so as to determine the light emitting parameters of the laser to emit light in a light emitting mode.

In some embodiments of the present disclosure, the configuration data may be input to the control unit through an external interface, or may be obtained from another storage unit by the control unit, which embodiments of the present disclosure are not limited thereto.

In a specific implementation, the laser driving circuit in the above embodiment may be applied to any device that needs to drive a laser, and a specific application example is given below.

Referring to fig. 6, which is a schematic diagram of an illumination system in an embodiment of the present disclosure, in some embodiments of the present disclosure, an illumination system 300 may include a laser module 100 and a laser driving circuit 200 of any of the foregoing embodiments, wherein:

the laser module 100 is suitable for providing illumination light, the laser module 100 comprises a plurality of lasers, and cathodes of the lasers are connected with each other and grounded;

the laser driving circuit 200 is coupled to the anode of each laser, and is adapted to provide driving signals for each laser to adjust the light emitting parameters of the corresponding laser.

The specific structure and the light emitting principle of the laser module 100 can be referred to the foregoing examples, and will not be described herein in detail.

The specific structure and driving principle of the laser driving circuit 200 are referred to in the foregoing examples, and will not be described in detail herein.

In addition, the embodiments of the present disclosure further provide a lidar corresponding to the laser driving circuit of any of the above embodiments, and detailed description will be made with reference to the accompanying drawings by way of specific embodiments.

Referring to fig. 7, which is a schematic structural diagram of a laser radar in the embodiment of the present disclosure, in some embodiments of the present disclosure, a laser radar M0 is adapted to detect a target MA, and may specifically include a laser module M1, an optical system M3, an echo detection device M4, a computing system M5, and a laser driving circuit M2 of any of the foregoing embodiments, where:

the laser module M1 comprises a plurality of lasers, wherein cathodes of the lasers are connected with each other and grounded, and the laser module M1 is suitable for providing detection light;

the laser driving circuit M2 is coupled with the anode of each laser and is suitable for driving the lasers in the laser module M1 to emit light;

an optical system M3 adapted to transmit the detection light to the detection target object and transmit the reflected light of the detection target object to the echo detection device M4;

the echo detection device M4 is suitable for acquiring the receiving time of the reflected light;

the computing system M5 is adapted to calculate the distance of the detection target object based on the emission time of the detection light and the reception time of the reflected light.

In the embodiment of the present disclosure, the laser driving circuit M2 in the laser radar M0 may be the laser driving circuit described in the embodiment of the present disclosure to implement laser scanning to obtain corresponding point cloud data, and specific structures, working principles, advantages and the like of the laser driving circuit may be referred to the foregoing embodiments and are not described herein again.

In a specific implementation, the laser in the laser module M1 may be, for example, an edge emitting laser (Edge Emitting Laser, EEL) or a Vertical-Cavity surface emitting laser (Vertical-Cavity SurfaceEmittingLaser, VCSEL), which is not limited to the type of laser used in the embodiments of the present disclosure.

It is also understood that the laser driving circuit described above may also be applied to industrial processing fields, consumer electronics, laser medical devices, and the like.

As a specific example, the industrial processing field may include: cell coating, soldering, wafer annealing, quenching, rapid prototyping, surface treatment, and the like.

Consumer electronics may include robots, 3D face recognition devices, AR/VR, cell phones, and the like.

The laser medical equipment can comprise a laser dehairing instrument, a laser physiotherapy instrument, a blood oxygen pulse measuring instrument and the like.

The embodiments of the present specification also provide a laser driving method corresponding to the laser driving circuit of any of the above embodiments, and detailed description will be made below by specific embodiments with reference to the accompanying drawings.

As shown in fig. 8, a flowchart of a laser driving method according to an embodiment of the present disclosure may adjust the light emitting parameters of the corresponding lasers in the laser module, where the cathodes of the lasers are connected to the ground.

The laser driving method may be specifically performed as follows:

s11, working impedance of each laser in the light emitting process is obtained, and corresponding impedance sampling signals are obtained.

S12, generating a driving control signal corresponding to the working impedance according to the working impedance corresponding to the impedance sampling signal and the mapping relation between the preset impedance and the driving voltage.

And S13, responding to the driving control signal, and generating a driving signal corresponding to the working impedance so as to adjust the light emitting parameters of the corresponding lasers.

By adopting the driving method of the lasers, the driving signals corresponding to the working impedance can be provided according to the working impedance of each laser in the light emitting process, so that each laser can work under proper electrical parameters, and the light emitting consistency of the lasers can be improved.

Although the embodiments of the present invention are disclosed above, the present invention is not limited thereto. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be assessed accordingly to that of the appended claims.

Claims

1. A laser driver circuit coupled to a laser module, the laser module comprising a plurality of lasers, cathodes of each laser being connected to ground, wherein the laser driver circuit comprises:

the driving units are respectively coupled with the anodes of the lasers and the control unit and are suitable for responding to the driving control signals to generate driving signals corresponding to the working impedance so as to adjust the luminous parameters of the corresponding lasers;

Wherein the driving unit includes: the device comprises a driving module, a comparing module, a switching module and a feedback module, wherein:

2. The laser driving circuit according to claim 1, wherein the sampling unit includes: a plurality of first sampling resistors, a plurality of second sampling resistors, a plurality of gating modules, and a plurality of sampling modules, wherein:

the second end of the second sampling resistor is grounded.

3. The laser driving circuit according to claim 2, wherein the sampling module comprises an operational amplifier, a first input terminal of the operational amplifier is coupled to the second terminal of the gating module and the anode of the laser, respectively, a second input terminal thereof is coupled to the first terminal of the second sampling resistor, and an output terminal thereof is coupled to the control unit and adapted to output the impedance sampling signal.

4. The laser driver circuit of claim 2, further comprising:

the logic operation unit is respectively coupled with each sampling module and the control unit and is suitable for executing logic operation on the impedance sampling signals output by each sampling module to obtain a logic operation result;

5. The laser driver circuit of claim 2, further comprising:

the light intensity detection unit is coupled with the control unit and is suitable for detecting the luminous power of each laser and generating a corresponding light intensity detection signal to the control unit;

6. The laser driver circuit of claim 1, wherein the feedback module comprises: a first voltage comparator, a current comparator, and a second voltage comparator, wherein:

7. The laser driver circuit of claim 6, wherein the switching module comprises a first transistor, a second transistor, and a third transistor, and wherein the first transistor and the second transistor are different;

8. The laser driving circuit according to any one of claims 1 to 7, further comprising:

9. The laser driving circuit according to claim 8, wherein the voltage protection unit includes: error amplifier, voltage dividing module and first resistance, wherein:

the second end of the voltage dividing module is coupled with the driving unit.

10. The laser driver circuit of claim 8, further comprising:

the voltage conversion unit is coupled between the voltage protection unit and the driving unit, and is suitable for converting the divided voltage to obtain a converted voltage and outputting the converted voltage to the driving unit.

11. The laser driving circuit according to claim 10, wherein the voltage conversion unit includes: a pulse amplifier and a capacitor, wherein:

the second end of the capacitor is grounded.

12. The laser driving circuit according to any one of claims 1 to 7, further comprising:

And the configuration unit is coupled with the control unit and is suitable for carrying out functional configuration on the control unit based on the configuration data so as to determine the light emitting parameters of the laser to emit light in a light emitting mode.

13. A lighting system, comprising:

a laser driver circuit as claimed in any one of claims 1 to 12, coupled to the anode of each laser, adapted to provide a drive signal to each laser to adjust the emission parameters of the respective laser.

14. A lidar, comprising: a laser module, an optical system, an echo detection device and a computing system, and a laser driving circuit according to any one of claims 1-12, wherein: