Laser emission drive circuit and laser radar

Abstract

A laser emission drive circuit and laser radar, wherein the drive circuit includes: a drive control module configured to receive an input pulse signal and a digital control signal and output a control level signal; wherein the digital control signal is used to adjust the magnitude of the control level signal output by the drive control module, and the pulse signal is used to control whether the drive control module outputs the control level signal; a drive module connected to the drive control module and a power supply, and configured to provide a drive current to a light-emitting device based on the control level signal to drive the light-emitting device to emit light; and a mirror feedback module connected to the drive control module and configured to provide a closed-loop feedback signal that adjusts the output of the drive control module to offset fluctuations in the drive current flowing through the light-emitting device due to temperature drift of the drive module. The above solution can improve the control accuracy of the laser emission light intensity.

Description

Technical Field

[0001] The embodiments of this specification relate to the field of circuit technology, and in particular to a laser emission drive circuit and a laser radar. Background Art

[0002] With the rapid development of artificial intelligence (AI), applications such as autonomous driving, facial recognition, and 3D photography are gradually maturing. LiDAR, as an important stereoscopic imaging sensor, has become a fundamental requirement for the implementation of these applications.

[0003] The working principle of lidar is to transmit a detection signal (laser beam or light signal) to the target, and then compare the received signal reflected from the target (target echo) with the transmitted detection signal. After appropriate processing, measurement information such as the distance and direction of the target can be obtained.

[0004] The light-emitting device is an important component of the entire laser radar. In the application of laser ranging radar, in order to achieve higher ranging accuracy, longer detection distance, and higher scanning rate, the light-emitting device is required to generate a laser pulse signal with a fast leading edge, high peak power, and narrow pulse width, which is used as a detection signal. The laser pulse signal has a fast leading edge and a small time error, so the equivalent distance error is small; the peak power is high, the longer the distance for the energy to decay to 0, and the narrower the pulse width (abbreviated as "pulse width"), the more laser pulses can be emitted continuously within the same time interval. In order to ensure that saturation distortion does not occur for long, medium, and short distance detection, the light-emitting energy of the laser is required to be able to be dynamically adjusted within a wide range. For example, a pulse signal with high energy can be emitted at long distances, and a pulse signal with low energy can be emitted at close distances.

[0005] Since the performance of the laser light source itself is generally good enough to fully meet the requirements of fast leading edge, high peak power and narrow pulse width, the main factor affecting the signal quality of the laser pulse output by the laser radar is the performance of the laser radar driving circuit. Summary of the Invention

[0006] In view of this, the embodiments of this specification provide a laser emission driving circuit and a laser radar to improve the control accuracy of the laser emission light intensity.

[0007] The embodiment of this specification provides a laser emission driving circuit, the driving circuit comprising:

[0008] a drive control module configured to receive an input pulse signal and a digital control signal, and output a control level signal; wherein the digital control signal is used to adjust the magnitude of the control level signal output by the drive control module, and the pulse signal is used to control whether the drive control module outputs the control level signal; and

[0009] a driving module connected to the driving control module and the power supply, and configured to provide a driving current to the light emitting device based on the control level signal, so as to drive the light emitting device to emit light;

[0010] The mirror feedback module is connected to the driving control module and is configured to provide a closed-loop feedback signal for adjusting the output of the driving control module to offset the fluctuation of the driving current flowing through the light-emitting device caused by the temperature drift of the driving module.

[0011] Optionally, the drive control module includes a digital-to-analog conversion unit and a voltage stabilization unit;

[0012] The digital-to-analog conversion unit is adapted to convert the digital control signal into an analog voltage signal and input the analog voltage signal into the voltage stabilization unit;

[0013] The voltage stabilizing unit is adapted to receive the analog voltage signal and the closed-loop feedback signal and output a regulated voltage signal;

[0014] The input end of the mirror feedback module is a port for outputting the voltage stabilization signal, the output end of the mirror feedback module is coupled to the input end of the voltage stabilization unit, and the mirror feedback module includes: the driving module and a mirror structure of the light emitting device.

[0015] Optionally, the drive control module further includes a switch unit, wherein:

[0016] The voltage stabilizing unit is coupled to the switch unit and is adapted to perform a voltage stabilizing operation on the pulse signal input to the control terminal of the switch unit according to the voltage stabilizing signal;

[0017] The switch unit is adapted to receive the pulse signal stabilized by the voltage stabilizing unit, determine whether to conduct the power supply of the driving module and the path between the switch unit and the ground according to the pulse signal, and provide the control level signal to the driving module when conducting.

[0018] Optionally, the light emitting device includes: a laser; the driving module includes: a first transistor, wherein:

[0019] The control electrode of the first transistor is connected to the drive control module, the first electrode of the first transistor is connected to the power supply of the drive module, and the second electrode of the first transistor is connected to the anode of the laser;

[0020] The drive control module also includes: a first level shifter, which is connected to the switch unit, the control electrode of the first transistor and the power supply of the drive module, suitable for providing a voltage drop, and outputting the control level signal based on the peak level of the pulse signal output by the switch unit to control the opening and closing of the first transistor.

[0021] Optionally, the mirror feedback module includes: a first resistor, a second transistor, and a second level shifter, wherein:

[0022] a first resistor, forming a mirror structure with the laser;

[0023] a second transistor forming a mirror structure with the first transistor, wherein a first electrode of the second transistor is connected to a preset reference power supply, and a second electrode of the second transistor is connected to the first resistor;

[0024] The second level shifter forms a mirror structure with the first level shifter, wherein the second level shifter is connected to the voltage stabilizing unit, the control electrode of the second transistor and the reference power supply, is suitable for providing a voltage drop, and controls the opening and closing of the second transistor based on the control level signal transmitted by the voltage stabilizing unit.

[0025] Optionally, the first level shifter includes: a third transistor and a second resistor, wherein: a control electrode of the third transistor is connected to the output end of the switch unit, and a first electrode of the third transistor is connected to the power supply of the driving module and to the control electrode of the first transistor through the second resistor;

[0026] The second level shifter includes: a fourth transistor and a third resistor, wherein: a control electrode of the fourth transistor is connected to the output terminal of the voltage stabilizing unit, a first electrode of the fourth transistor is connected to the preset reference power supply and to the control electrode of the second transistor through the third resistor, and a second electrode of the fourth transistor is grounded;

[0027] The resistance values ​​of the first resistor and the laser on-resistance, the resistance values ​​of the third resistor and the second resistor, the transconductance of the second transistor and the first transistor, and the transconductance of the fourth transistor and the third transistor are set so that the voltage difference between the control terminals of the second transistor and the first transistor is the same.

[0028] Optionally, the third resistor is an adjustable resistor, suitable for being adjusted based on the voltage of the regulated signal.

[0029] Optionally, the light emitting device includes a laser;

[0030] The driving module includes: a fifth transistor, wherein a first electrode of the fifth transistor is connected to the cathode of the laser, and a second electrode of the fifth transistor is connected to the ground;

[0031] The mirror feedback module includes: a sixth transistor and a first resistor, wherein the first resistor forms a mirror structure with the laser; the first electrode of the sixth transistor is coupled to the first resistor, the first electrode and the second electrode of the sixth transistor are also connected to the inverting input end of the voltage stabilizing unit, and the control electrode of the sixth transistor is connected to the output end of the voltage stabilizing unit.

[0032] Optionally, a parameter ratio of a device between the voltage control terminal of the drive control module and the drive module and the light-emitting device to corresponding devices of the mirror feedback module is not less than 100.

[0033] Optionally, the voltage stabilizing unit includes:

[0034] an operational amplifier, whose non-inverting input terminal is suitable for inputting the analog voltage signal, whose inverting input terminal is connected to the output terminal of the mirror feedback module, and whose voltage output terminal is connected to the switching unit and is suitable for outputting the regulated voltage signal; and / or

[0035] The drive control module further includes:

[0036] The narrow pulse generator is coupled to the switch unit and is adapted to generate a first narrow pulse based on the pulse signal, wherein the pulse width of the first narrow pulse is smaller than the pulse width of the input pulse signal.

[0037] The embodiment of this specification further provides a laser radar, the laser radar comprising:

[0038] A controller, a plurality of light-emitting devices, and a plurality of driving devices, wherein:

[0039] The driving device includes the laser emission driving circuit described in any of the aforementioned embodiments;

[0040] The plurality of light emitting devices are respectively coupled to corresponding driving devices and are adapted to emit light under the drive of the laser emission driving circuit;

[0041] The controller is adapted to be coupled to the plurality of driving devices respectively, and is adapted to output a pulse signal and a digital control signal to the laser emission driving circuit to drive the corresponding light emitting device to emit light.

[0042] By adopting the laser emission driving circuit in the embodiment of this specification, a closed-loop feedback signal for adjusting the output of the driving control module is provided through a mirror feedback module, which can offset the fluctuation of the driving current flowing through the light-emitting device due to the temperature drift of the driving module. Therefore, the driving device can stably and accurately generate the driving current based on the control level signal provided by the driving control module to drive the light-emitting device to emit light, thereby improving the control accuracy of the light intensity of the light-emitting device.

[0043] Furthermore, the mirror feedback module and the driving module share a driving control module. Specifically, its input end is coupled to the output end of the voltage stabilizing unit, and its output end is coupled to the input end of the voltage stabilizing unit. The voltage stabilizing module can be used to stabilize the peak value of the pulse signal, thereby stably controlling the control end voltage of the driving module. Since the mirror feedback module includes a mirror structure of the driving module and the light-emitting device, as well as a mirror connection between the driving module and the light-emitting device, the impact of temperature changes on the driving module can be reflected in the devices at the corresponding positions of the mirror feedback module. Through the output end of the voltage stabilizing unit and the feedback signal input back to the voltage stabilizing unit, a negative feedback loop can be formed, thereby enabling the driving current output by the driving module to be stably controlled, thereby achieving precise control of the light intensity of the light-emitting device.

[0044] Furthermore, since the parameter ratio of the devices from the voltage-stabilized signal output end of the drive control module to the drive module and the light-emitting device to the corresponding devices of the mirror feedback module is not less than 100, the DC power consumption brought by the mirror feedback module is much smaller than the static power consumption brought by the drive control module. Therefore, the impact on the normal operation of the light-emitting path of the light-emitting device is extremely small, and therefore it will not affect the accurate measurement of high-precision measuring devices such as laser radars that include the laser emission drive circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0046] Figure 1 A schematic structural diagram of a laser emission drive circuit is shown;

[0047] Figure 2A and Figure 2B The functional module structure diagram and example circuit diagram of another laser emission drive circuit are shown respectively;

[0048] Figure 3 Shown Figure 2B The driving current waveform of the example circuit corresponding to different temperatures;

[0049] Figure 4 A schematic diagram of the structure of a laser radar in an embodiment of this specification is shown;

[0050] Figure 5 A schematic diagram of the structure of a laser emission drive circuit according to an embodiment of this specification is shown;

[0051] Figure 6 shows a functional module structure diagram of a laser emission drive circuit in some embodiments of this specification;

[0052] Figure 7 Shown Figure 6 An example circuit diagram of a laser emission drive circuit shown;

[0053] Figure 8 Shown Figure 6 Another example circuit diagram of the laser emission drive circuit shown;

[0054] Figure 9 An example circuit diagram of a laser emission driving circuit in some other embodiments of this specification is shown;

[0055] Figure 10 Shown Figure 7 The voltage waveform corresponding to the example circuit shown;

[0056] Figure 11 Shown Figure 7 The relationship between the Vsg voltage waveform and the first transistor drain output current waveform in the example shown;

[0057] Figure 12 Shown Figure 8 The driving current waveforms corresponding to different third resistors in the example circuit shown;

[0058] Figure 13 Shown Figure 7 The example circuit shown shows the driving current waveforms corresponding to different temperatures. DETAILED DESCRIPTION

[0059] As described in the background, the signal quality of laser pulses output by a LiDAR is primarily influenced by the performance of its laser emission driver circuit. However, the inventors have studied existing laser emission driver circuits and found that current driver circuit solutions still have many problems.

[0060] Reference Figure 1The schematic diagram of the structure of a laser emission driving circuit is shown, wherein the driving circuit 10 includes a power field effect transistor (Power FET), and the pulse driving signal Vin is input into the gate of the Power FET via the gate driver 11. The source of the Power FET is grounded, and the drain is connected to the laser LD. The current flowing through the laser LD can be changed by controlling the pulse width of the pulse driving signal Vin of the driving circuit or the power supply voltage HV, thereby changing the luminous energy value. Specifically, the pulse width of each pulse driving signal Vin corresponds to the luminous duration of the laser LD. When the pulse driving signal Vin changes from a low level to a high level, the Power FET can be turned on, thereby HV A discharge path is formed among the laser LD, Power FET and ground (GND), and the laser LD starts to emit light.

[0061] Widening the pulse width of the pulse drive signal Vin limits the interval between adjacent multi-pulses emitted by the laser, increasing the measurement dead time and preventing the achievement of a high repetition rate. Luminous energy is equal to the luminous power multiplied by the time width. The luminous power is proportional to the current input to the laser LD. Therefore, changing the pulse width of the input pulse drive signal Vin can proportionally change the luminous energy. When the on-resistance of the laser LD and the Power FET is constant, changing the power supply voltage HV can change the current flowing into the laser LD, thereby changing the luminous energy.

[0062] Therefore, in Figure 1 In the driving circuit shown, if you want to increase the light intensity of the laser LD, you can 1) increase the pulse width of the pulse driving signal Vin; or 2) increase the power supply voltage HV. However, for 1), increasing the pulse width of the pulse driving signal Vin will cause the output pulse of the optical signal to become wider, and the pulse widening limits the interval between adjacent pulses, increases the dead time of the measurement, and cannot achieve a higher repetition frequency. In addition, since the peak power current of the output laser pulse does not change, the detection distance corresponding to the non-saturation distortion does not change, so it is impossible to achieve non-saturation distortion detection at far, medium and near distances at the same time. As for 2), the power supply voltage HV is generated by a boost circuit. It is necessary to increase HV by controlling the boost circuit, which will make the switching rate of the boost circuit lower, resulting in a longer stabilization time between the two adjustments, and will also make the system control more complicated.

[0063] In order to solve the above problems, the prior art has proposed some laser emission driving circuits, such as Figure 2A and Figure 2B The functional module structure diagram and example circuit diagram of another laser emission driving circuit are shown respectively.

[0064] Combined with the first and following Figure 2A and Figure 2BThe principle is explained by completing a laser pulse emission process: the input pulse signal Vin is adjusted to a few nanoseconds by the narrow pulse generator 23, and then amplified by the intermediate stage amplifier link 24 and output to the final stage inverter 25. The power supply of the final stage inverter 25 is provided by the voltage follower 22, and the input of the voltage follower 22 comes from the V generated by the digital-to-analog converter 21. REF , then the peak value of the pulse high level output by the final inverter 25 is stable and V REF , the level shifter 26 is driven by the final inverter 25, and the output of the level shifter 26 controls the opening and closing of the P-type power MOSFET 27, thereby controlling whether the semiconductor laser 28 emits light. Specifically, as Figure 2B In the embodiment, the output of the final-stage inverter 25 controls the opening and closing of the field-effect transistor LDNMOS. Once the field-effect transistor LDNMOS is turned on, the path from the power supply HVDD1 to the resistor R1 to the field-effect transistor LDNMOS to the ground (GND) is turned on. If the current flowing through this path is I, a voltage drop LV is generated across the resistor R1, and the node voltage input to the field-effect transistor LDPOS is HV(=HVDD1)-LV(=HVDD1-I*R1). Vsg=LV>Vth, and the field-effect transistor LDPMOS is turned on, where Vth is the gate threshold voltage of the field-effect transistor LDPOS, and the laser LD emits light. If the output of the final-stage inverter 25 is insufficient to turn on the field-effect transistor LDPOS, the path from the power supply HVDD1 to the resistor R1 to the field-effect transistor LDNMOS to the ground (GND) is turned off. The node voltage input to the field-effect transistor LDPMOS is HV=HVDD1, Vsg=0, which is less than the gate threshold voltage Vth. The LDPMOS cannot be turned on, and the laser LD does not emit light.

[0065] The study found that in Figure 2A and Figure 2B In some of the laser emission drive circuits shown, it is difficult to accurately control the laser emission intensity. Specifically:

[0066] 1) For example, it is difficult to accurately control the driving current of the laser by controlling the voltage output by the analog-to-digital converter 21, for example, Figure 2B In the embodiment, there is no exact corresponding relationship between the voltage output by the voltage-type DAC 21 and the peak value of the output current of the MOS tube LDPMOS.

[0067] 2) The peak value of the laser driving current drifts greatly with temperature, such as Figure 3The driving current change waveform corresponding to a certain laser pulse emitted by the laser shown in the figure, wherein the temperature corresponding to waveform b31 is -40°C, the temperature corresponding to waveform b32 is 25°C, and the temperature corresponding to waveform b33 is 125°C. By comparing the peak values ​​of waveforms b31, b32, and b33, it can be seen that the driving current, that is, the output current of the LDPMOS, has temperature drift (referred to as "temperature drift"). The higher the temperature, the smaller the output current, and the corresponding laser light intensity is smaller.

[0068] To this end, the embodiments of this specification provide a laser emission driving circuit that can improve the accuracy of driving current control, as well as an example of a laser radar to which the laser emission driving circuit of the embodiments of this specification can be applied. By utilizing the input pulse voltage signal and digital control signal to control the voltage / current provided to the light-emitting device, the light emission of the light-emitting device can be precisely controlled.

[0069] In the embodiment of this specification, the laser radar may include: a controller, a plurality of light-emitting devices, and a plurality of driving devices, wherein:

[0070] The driving device may include the laser emission driving circuit described in the embodiments of this specification;

[0071] The plurality of light emitting devices are respectively coupled to corresponding driving devices and are adapted to emit light under the drive of the laser emission driving circuit;

[0072] The controller is adapted to be coupled to the plurality of driving devices respectively, and adapted to output pulse signals and digital control signals to the laser emission driving circuit to drive the corresponding light emitting devices to emit light. The following first briefly introduces the laser radar through some examples.

[0073] Figure 4 Figure 2 shows a schematic diagram of the structure of a laser radar. Figure 4 As shown in , the laser emission driving circuit in the embodiment of this specification can be applied to a laser radar 40. Specifically, the laser radar 40 may include a driving device 41 of the laser emission driving circuit in the embodiment of this specification, and a light emitting device 42, wherein the driving device 41 may be one or more, and correspondingly, the light emitting device 42 may also be one or more, and each driving device 41 is used to drive a corresponding light emitting device 42. The specific structure and working principle of the laser emission driving circuit included in the driving device will be combined in subsequent embodiments. Figures 5 to 13 Provide a detailed description.

[0074] Each driver 41 is connected to a power supply 43 and to the anode (i.e., high-side) of the corresponding light-emitting device 42. The cathode (i.e., low-side) of the light-emitting device 42 is grounded (GND). The power supply 43 provides a power supply voltage HVDD1 to the driver 41. The driver 41 receives a pulse signal Vin and a digital control signal Din and generates a drive current Id to output to the light-emitting device 42. The light-emitting device 42 converts the input drive current Id into light energy. The laser radar 40 may also include a control unit 44, which is connected to the driver 41 and can generate a separate pulse signal Vin and digital control signal Din for each driver 41 according to ranging requirements. This allows each light-emitting device 42 to be cycled through and selected to emit light, or some light-emitting devices 42 can be selected to emit light simultaneously. The specific lighting method can be determined according to the detection requirements and is not limited here. In other words, the control unit 44 can determine the light-emitting device 42 to be driven and provide the corresponding pulse signal Vin and digital control signal Din to the driver 41 of the light-emitting device 42.

[0075] Those skilled in the art will appreciate that although Figure 4 The input of each driving device 41 is shown as Vin and Din, but depending on different ranging requirements, the pulse signal Vin and digital control signal Din of each driving device 41 can be different.

[0076] Here, the pulse signal Vin is a trigger signal for the driver 41, which is issued each time the radar is ranging (for example, scanning every 1 microsecond). Each pulse signal Vin can include one or several (such as 2-4) narrow pulses, each of which has a pulse width of tens of nanoseconds and is proportional to the luminous power of the light-emitting device 42. The digital control signal Din is a control signal for the driver 10, which can change as the ranging requirements change. For example, when the environmental obstacle has a high reflectivity surface, its value can be reduced, and when the environmental obstacle has a low reflectivity surface, its value can be increased.

[0077] In addition, although Figure 4 The driving device 41 and the light emitting device 42 are shown in a one-to-one correspondence, but those skilled in the art will appreciate that, depending on actual conditions, one driving device 41 can drive multiple light emitting devices 42 .

[0078] The light emitting device 42 may be, for example, an edge emitting laser (EEL) or a vertical-cavity surface emitting laser (VCSEL).

[0079] In the specific implementation, continue to refer to Figure 4One or more driving devices 41 can be packaged on a chip 4A, and one or more light-emitting devices 42 can be packaged on another chip 4B. The chip 4A and the chip 4B can share the same power supply 43.

[0080] Those skilled in the art will appreciate that other parts of the laser radar 40 , such as the receiver, etc., are omitted here for the sake of brevity.

[0081] The laser emission driving circuit of the embodiment of this specification can also be applied to cathode driven lasers, laser cathode driven laser radars and Figure 4 The difference is that the driving device is coupled between the cathode of the light emitting device and the ground (GND), and the anode of the light emitting device is connected to the power supply, which will not be repeated here.

[0082] Figure 5 The schematic diagram of the structure of a laser emission drive circuit in an embodiment of the present specification is shown, wherein the laser emission drive circuit 50 may include a drive control module 51, a drive module 52, and a mirror feedback module 53. The drive control module 51 is configured to receive an input pulse signal Vin and a digital control signal Din, and output a control level signal Vx. The digital control signal Din is used to adjust the magnitude of the control level signal Vx output by the drive control module 51, and the pulse signal Vin is used to control whether the drive control module 51 can output the control level signal Vx (of course, Vx always outputs a certain numerical signal. The output here represents the output of the control level signal Vx sufficient to turn on the drive module. When the drive module is not turned on, Vx = HVDD1; when the drive control module is turned on, Vx < HVDD1). In addition, the digital control signal Din can stabilize the peak value of the pulse signal Vin, which affects the magnitude of the control level signal Vx.

[0083] The driving module 52 is connected to the driving control module 51 and the power supply HVDD1, and is used to provide a driving current Id to the light emitting device based on the control level signal Vx, so as to drive the light emitting device 5A to emit light;

[0084] The mirror feedback module 53 is configured to provide a closed-loop feedback signal Vf for adjusting the output of the drive control module 50 to offset the fluctuation of the drive current flowing through the light emitting device (such as a laser) 5A caused by the temperature drift of the drive module 52.

[0085] By adopting the laser emission driving circuit in the embodiment of this specification, a closed-loop feedback signal for adjusting the output of the driving control module is provided through a mirror feedback module, which can offset the fluctuation of the driving current flowing through the light-emitting device due to the temperature drift of the driving module. Therefore, the driving device can stably and accurately generate the driving current based on the control level signal provided by the driving control module to drive the light-emitting device to emit light, thereby improving the control accuracy of the light intensity of the light-emitting device.

[0086] In some embodiments of this specification, reference is made to Figure 5 and Figure 6 The driver control module 51 may include a control voltage terminal VA that outputs a corresponding control voltage based on the digital control signal Din. The control voltage output by the control voltage terminal VA is suitable for adjusting the magnitude of the control level signal output by the driver control module 51. The mirror feedback module 53 is coupled to the voltage control terminal VA of the driver control module 51 (which is also the output terminal of the voltage stabilizing unit A2; the voltage VA can be referred to as a regulated voltage signal). Specifically, the input terminal of the mirror feedback module 53 is the port where the regulated voltage signal VA is output by the voltage stabilizing unit A2, and the output terminal 53 of the mirror feedback module is coupled to the input terminal of the voltage stabilizing unit A2. In other words, the mirror feedback module 53 and the driver module 6B share the driver control module 51. The mirror feedback module 53 controls the control level input to the driver module by the driver control module 51 through closed-loop control of the regulated voltage signal VA output by the voltage stabilizing unit A2. The mirror feedback module 53 may include: a mirror structure between the driver module 52 and the light-emitting device 5A, and a mirror structure connecting the voltage control terminal VA of the driver control module 51 to the light-emitting device 5A.

[0087] Reference Figure 6 The functional module structure diagram of the laser emission driving circuit in some embodiments of the present specification is shown, wherein the laser emission driving circuit 60 includes: a driving control module 6A and a driving module 6B.

[0088] More specifically, the drive control module 6A may include a digital-to-analog conversion unit A1, a voltage stabilization unit A2, and a switch unit A3, wherein:

[0089] The digital-to-analog conversion unit A1 can convert the digital control signal into an analog voltage signal;

[0090] The voltage stabilizing unit A2 is connected to the switching unit A3 of the digital-to-analog conversion unit A1, can receive the analog voltage signal and the closed-loop feedback signal, output a stabilizing signal, and perform a voltage stabilizing operation on the pulse signal input to the control terminal of the switching unit according to the stabilizing signal, that is, stabilize the peak value of the pulse signal;

[0091] The switch unit A3 is adapted to receive the pulse signal stabilized by the voltage stabilizing unit, determine whether to turn on the power supply of the driving module and the path between the switch unit and the ground according to the pulse signal, and provide the control level signal to the driving module 6B when turned on.

[0092] Continue to refer to Figure 6 , the embodiments of this specification can be applied to the case where the light emitting device includes a laser, such as Figure 6 In the light emitting device 6C shown, an anode driven semiconductor laser U6 is used. Corresponding to this light emitting device, in some embodiments of this specification, the driving module 6B includes: a first transistor U5, wherein:

[0093] The control electrode of the first transistor U5 is connected to the drive control module, the first electrode of the first transistor is connected to the power supply of the drive module, and the second electrode of the first transistor is connected to the anode of the semiconductor laser U6;

[0094] like Figure 6 As shown, the driving control module 6A further includes a first level shifter U4, which is connected to the switching unit A3, the control electrode of the first transistor U5 and the power supply HVDD1 of the driving module, is suitable for providing a voltage drop, and controls the opening and closing of the first transistor U5 based on the control level signal Vx output by the switching unit A3.

[0095] For the above-mentioned drive module structure solution, the following mirror feedback module solution can be adopted:

[0096] Continue to refer to Figure 6 , the mirror feedback module 6D includes: a first resistor R1, a second transistor U8 and a second level shifter U7, wherein:

[0097] The first resistor R1 forms a mirror structure with the semiconductor laser U6;

[0098] A second transistor U8 forms a mirror structure with the first transistor U5, wherein a first electrode of the second transistor U8 is connected to a preset reference power supply VDD2, and a second electrode of the second transistor U8 is connected to the first resistor R1;

[0099] The second level shifter U7 forms a mirror structure with the first level shifter U4, wherein the second level shifter U7 is connected to the voltage stabilizing unit A2, the control electrode of the second transistor U8 and the reference power supply VDD2, is suitable for providing a voltage drop, and controls the opening and closing of the second transistor U8 based on the control level signal transmitted by the voltage stabilizing unit A2.

[0100] In some embodiments of this specification, reference is made to Figure 7 An example circuit diagram of a laser emission driving circuit is shown, wherein the first level shifter U4 may include: a third transistor M3 and a second resistor R2, wherein: the control electrode of the third transistor M3 is connected to the output end of the switch unit A2, and the first electrode of the third transistor M3 is connected to the power supply HVDD1 of the driving module through the second resistor R2, and is connected to the control electrode of the first transistor LDP1;

[0101] Correspondingly, the second level shifter U7 having a mirror-image structure with the first level shifter U4 includes: a fourth transistor M4 and a third resistor R3, wherein: a control electrode of the fourth transistor M4 is connected to the output terminal VA of the voltage stabilizing unit, a first electrode of the fourth transistor M4 is connected to the reference power supply VDD2 and to the control electrode of the second transistor LDP2 through the third resistor R3, and a second electrode of the fourth transistor M4 is grounded (GND).

[0102] In a specific implementation, the transistors in the embodiments of this specification, such as the first transistor LDP1, the second transistor LDP2, the third transistor M3, the fourth transistor M4, etc., can be field effect transistors, thyristors, etc. If field effect transistors are used, they can be P-channel field effect transistors, such as P-type power MOSFETs, or N-channel field effect transistors, such as N-type power MOSFETs, such as Figure 7 In the example circuit diagram shown, the first transistor LDP1 adopts a P-type power MOSFET. Based on the mirror structure, the second transistor has the same structure as the first transistor, so the second transistor LDP2 also adopts a P-type power MOSFET; for example, the fourth transistor structure is the same as the third transistor structure, for example, both use N-channel field effect transistors M3 and M4.

[0103] In a specific implementation, in order to achieve a precise mirror structure, the parameter ratios of the devices between the voltage control end of the drive control module and the drive module and the light-emitting device and the corresponding devices of the mirror feedback module need to satisfy an appropriate proportional relationship, so that the mirror structure and the main drive circuit operate under similar working conditions.

[0104] Specifically, the resistance values ​​of the first resistor R1 and the on-resistance of the laser LD, the resistance values ​​of the third resistor R3 and the second resistor R2, the transconductance of the fourth transistor and the third transistor, and the transconductance of the second transistor LDP2 and the first transistor LDP1 are all in a preset proportional relationship. In other words, the approximate formula of the current I1P output by the first transistor LDP1 is: I1P = gm*(Vsg-Vthp) = V f / R1*q=V f / R1*R2 / R3, where gm is the transconductance of the first transistor LDP1, Vsg is the voltage difference between the source and gate of the first transistor LDP1 (also called the control terminal voltage difference of the first transistor LDP1), Vthp is the threshold voltage of the first transistor LDP1, and V f =VA (output voltage of voltage stabilizing unit U1). During operation, Vthp varies with temperature. To maintain a constant peak value of output current I1P, it is necessary to ensure that the voltage difference (Vsg-Vthp) remains constant. Therefore, the present application selects and sets parameters such as the closed loop of U7, U8, and U9, as well as the resistance values ​​of the third resistor R3 and the second resistor R2, the transconductance of the fourth transistor and the third transistor, and the transconductance of the second transistor LDP2 and the first transistor LDP1. This can automatically and in real time provide feedback on the output voltage VA of the voltage stabilizing unit U1, so that the current I2P flowing through the second transistor LDP2 remains constant, thereby controlling I1P to be approximately constant, thereby compensating for the temperature drift effect of the first transistor LDP1.

[0105] In some embodiments of this specification, Figure 5 As shown, the parameter ratio of the components between the voltage control terminal VA of the drive control module 51 and the drive module 52 and the light-emitting device 53 to the corresponding components of the mirror feedback module 53 is not less than 100. That is, p>100. In a specific implementation, the value of p can range from 100 to 1000. It will be understood that the above value range is only an example, and the specific value of p can also be greater than 1000.

[0106] Since the parameter ratio of the devices from the voltage control end of the drive control module to the drive module and the light-emitting device to the corresponding devices of the mirror feedback module is not less than 100, the DC power consumption brought by the mirror feedback module is much smaller than the static power consumption brought by the drive control module. Therefore, the impact on the normal operation of the light-emitting path of the light-emitting device is extremely small, and therefore it will not affect the accurate measurement of high-precision measuring devices such as laser radars that include the laser emission drive circuit.

[0107] In the specific implementation, refer to Figure 5 、 Figure 6 and Figure 7 , the voltage stabilizing unit U1 may include: an operational amplifier AMP.

[0108] The operational amplifier AMP has a non-inverting input (+) adapted to receive the analog voltage signal, and an inverting input (-) connected to the output of the mirror feedback module 6D (also providing the feedback signal). Its voltage output, connected to the switch unit A3 via a final-stage inverter U3, also serves as the signal input of the mirror feedback module 6D, adapted to output the regulated voltage signal. The mirror feedback module 53 and the driver module 6B share the driver control module 51. The mirror feedback module 53 controls the regulated voltage signal VA output by the regulated voltage unit A2 through closed-loop control, thereby controlling the control level inputted by the driver control module 51 to the driver module, thereby controlling the current flowing through the light-emitting device.

[0109] Continue to refer to Figure 6 and Figure 7 , the drive control module 6A may further include:

[0110] The narrow pulse generator U2 is coupled to the switch unit A3 and is adapted to generate a first narrow pulse based on the pulse signal Tr1 , wherein the pulse width of the first narrow pulse is smaller than the pulse width of the input pulse signal Tr1 .

[0111] In a specific implementation, the drive control module 6A may further include: an intermediate stage amplification link U10, which includes at least one stage amplification circuit, coupled between the narrow pulse generator U2 and the switch unit A3, and is suitable for performing a corresponding level of signal amplification on the first narrow pulse.

[0112] In a specific embodiment, the switch unit A3 includes: a final-stage inverter U3, the inverter U3 including a power supply terminal, an input terminal, and an output terminal, wherein:

[0113] The input end of the inverter U3 is suitable for coupling with a narrow pulse generator to output a pulse signal. The input end of the inverter U3 is connected to the output end VA of the voltage stabilizing unit A2, and the output end is connected to the first level shifter U4.

[0114] The following combination Figure 6 and Figure 7 The following describes the principle of precise control of laser emission by the laser emission drive circuit in the embodiment of this specification through the emission of a laser pulse:

[0115] First, the trigger signal Tr1 is transmitted along the narrow pulse generator U2 and the intermediate stage amplification link U10 (which includes at least one stage of amplification circuit) to the final stage inverter U3. After that, the first transistor U5 can be controlled to be on and off through the first level shifter U4. This path can be called a dynamic control path. At the same time, a static control path is formed through the voltage stabilizing unit U1, the second level shifter U7, the second transistor U8, the first resistor R1, to the inverting input terminal of the voltage stabilizing unit U1. Specifically, the drain voltage of the second transistor LDP2 can be guided to the inverting input terminal (-) of the voltage stabilizing unit U1, thereby forming a closed-loop negative feedback regulation of the output of the voltage stabilizing unit U1.

[0116] Through the above static control path, the output voltage VA of the voltage stabilizing unit U1 is controlled by the loop composed of the second level shifter U7, the second transistor U8, and the first resistor R1, then: VDAC=VA=VR, where VR=I 2P *R1, where I 2P represents the output current of the drain of the second transistor LDP2, R1 represents the resistance of the first resistor R1, and VR represents the voltage of the resistor R1.

[0117] In addition, the voltage difference between the source and gate of the second transistor LDP2 is Vsg1=I 1N *R2,I 1N is the current flowing through the fourth transistor M4; similarly, the voltage difference between the source and gate of the first transistor LDP1 is Vsg1=I 1N *R2.

[0118] In a specific implementation, the resistance ratio of the resistor R3 in the first level shifter U7 to the resistor R2 in the second level shifter U4 is selected so that I 2N =2I 1N / p, where p can be a positive integer, and it is recommended to be 100 or above, for example, it can be selected between 100 and 1000. Since p is a large value, a very small part is separated from the output end of the voltage stabilizing unit U1 to the second level shifter U7, and a large part is sent to the switch unit U3, and then to the first level shifter U4. R3 = p*R2 is selected, where p is an integer multiple, so Vsg1 = Vsg2; the ratio is selected so that the parameter ratio of the first transistor LDP1 and the second transistor LDP2 is q, then I 1p =I 2p *q, where q can be a positive integer. It is recommended to be 100 or above, for example, it can be selected between 100 and 1000.

[0119] Please continue to refer to Figure 7 , in the first level shifter U4, I 1p = VR / R1*p, where I1p is the peak current of the laser diode LD, I 1p When the pulse signal Tr1 is high and valid, if the preset reference power supply voltage VDD2 is low, in order to reduce the power consumption of the mirror feedback module, the reference power supply can use a low voltage power supply, such as 5V, p = R2 / R3, where the only variable is the voltage VR, so I 1p The loop formed by the second level shifter U7, the second transistor U8, and the first resistor R1 is determined. In other words, the loop formed by the second level shifter U7, the second transistor U8, and the first resistor R1 can reflect the current I of the laser diode LD. 1p changes in the situation.

[0120] Furthermore, as mentioned above, the first transistor LDP1 may have temperature drift, and the voltage output by the voltage-type DAC and the current I output by the first transistor LDP1 are 1p The corresponding relationship of the peak value will change with the temperature, and thus the output voltage VR of the voltage stabilizing unit will also fluctuate.

[0121] At the same time, according to VDAC=VA=VR, since the voltage follower U1 is a closed-loop self-regulating device, it will continuously tend to adjust VR to V through the closed-loop system. DAC , and as Figure 6 and Figure 7 As shown, V DAC It is determined by the digital input signal Din at the digital-to-analog converter U0 and can be precisely controlled. Therefore, the output current I of the first transistor U5 is 1p , that is, the driving current of the semiconductor laser U6 can be controlled stably, so the light intensity of the laser can be accurately controlled.

[0122] In summary, in the above embodiment, the voltage difference between the control terminals of the second transistor LDP2 and the first transistor LDP1 can be made the same by setting the resistance of the first resistor R1 and the on-resistance of the laser LD, the resistance of the third resistor R3 and the second resistor R2, the transconductance of the second transistor LDP2 and the first transistor LDP1, and the transconductance of the fourth transistor M4 and the third transistor M3.

[0123] In addition, since the ratio p is relatively large, the DC power consumption brought by the second level shifter U7, the second transistor U8 and the first resistor R1 is only about 1 / 1000 of the static power consumption brought by the entire voltage stabilization module. Therefore, the static power consumption introduced by the second level shifter U7, the second transistor U8 and the first resistor R1 is not large, which has little impact on the laser emission path, ensuring the normal operation of the laser.

[0124] To better understand the working principle of the laser emission drive circuit in this manual, you can refer to Figure 10 The voltage waveform shown in the figure, Figure 10 Shows that when there is a pulse signal input Figure 7 The voltage waveforms of multiple key nodes of the example circuit shown, where: the horizontal axis is the time axis, the unit is nanoseconds, the vertical axis is time, waveform b01 shows the voltage waveform of the input pulse signal Tr1; waveform b02 is the gate waveform of the first transistor LDP1, and waveform b03 shows the drain voltage waveform of the third transistor M3; waveform b04 shows the voltage waveform of the power supply HVDD1, that is, the source voltage waveform of the first transistor LDP1; waveform b05 shows the voltage waveform of the output end of the semiconductor laser LD; waveform b06 is the voltage waveform of the output end of the analog-to-digital converter U0 and the voltage waveform of the positive end of R1; waveform b07 shows the voltage waveform of the output end of the voltage stabilizing unit U1.

[0125] According to the derivation process of the above embodiment, the voltage difference Vsg2 between the source and the drain of the second transistor LDP2 is equal to I 2N *R2, and I 2N =gm M2 *V LDO , where gm is the transconductance, which indicates the relationship between the gate-source voltage difference and the drain current. Therefore, changing R3 can change the output voltage of the operational amplifier. The transconductance between the fourth transistor M2 and the first transistor LDP1 is proportional. The voltage difference between proportional devices is the same, but the current output by the drain is proportional. Please refer to Figure 11 As shown in the figure, the relationship between the Vsg voltage waveform b11 and the first transistor drain output current waveform b12 clearly shows that the two are in a linear proportional relationship.

[0126] From the above derivation process and Figure 11 From the relationship between the Vsg voltage waveform b11 and the first transistor drain output current waveform b12 shown, it can be seen that by adjusting the resistance value of the third resistor R3, different output current values ​​can be obtained. Therefore, the resistance value of the third resistor R3 can be set, and then by adjusting the resistance value of the third resistor, the light intensity of the laser can be adjusted accordingly.

[0127] Figure 8 The structure diagram of the laser emission driving device including the adjustable third resistor is shown. Figure 7The difference is that the third resistor R3 is an adjustable resistor. In a specific implementation, it can be adjusted based on the input digital control signal Din2. The digital control signal Din2 can be related to the voltage of the regulated signal, so that the resistance of the third resistor R3 can be adjusted based on the voltage of the regulated signal. In a specific implementation, a weighted resistor network DAC can be used to convert the digital control signal Din2 into a corresponding resistance value. Figure 12 Shown Figure 8 The driving current waveforms corresponding to different third resistors in the example circuit shown are shown, where the horizontal axis is time and the vertical axis is the driving current of the laser. Waveforms b21, b22, b23, and b24 correspond to the resistance values ​​of the third resistors being 1000Ω, 2000Ω, 3000Ω, and 4000Ω, respectively. Figure 12 It can be seen that the larger the resistance of the third resistor R3 is, the smaller the peak value of the driving current of the laser can be adjusted.

[0128] use Figure 7 The laser emission drive circuit shown in FIG. 1 compensates for temperature drift through a mirror feedback module, and the drive current waveform obtained at different temperatures is as follows: Figure 13 As shown, waveform b41, waveform b42 and waveform b43 are respectively Figure 7 The driving current waveform of the laser emission driving circuit shown in the figure is changed at -40℃, 25℃ and 125℃. Figure 13 and Figure 3 By comparison, it can be seen that the peak change of the driving current caused by temperature drift has been significantly reduced. By comparing and calculating the current peak data corresponding to the above waveforms, the degree of current peak drift with temperature has been reduced from 30% (at Figure 3 In the case of 125° to 40°, the peak current changes from 25A to 32A, which is about a 30% increase) to 4% (in Figure 13 From 125° to 40°, the peak current changes from 26A to 27A, an increase of approximately 4%. Based on the waveform comparison and test data comparison, it can be seen that the laser emission drive circuit according to the embodiment of this specification can achieve precise adjustment of the drive current peak based on the input digital control signal, thereby improving the precise adjustment of the laser emission light intensity.

[0129] More specifically, the laser emission driving current, that is, the output current I 1p The approximate formula can be expressed as: 1p=gm*(Vsg-Vthp), and the gate threshold voltage Vth of the field effect transistor LDP1 in the driving module will change with temperature. In order to keep the output current peak constant, it is necessary to ensure that the source-gate voltage difference and the gate threshold voltage difference Vsg-Vthp of the field effect transistor LDP1 remain unchanged. Through the loop composed of the second level shifter U7, the second transistor U8, and the first resistor R1, the output voltage VA of the operational amplifier AMP can be automatically feedback-regulated in real time, so that the current I corresponding to the first resistor in the mirror feedback module 2p , that is, the output current of the drain of the second transistor LDP2 remains unchanged, thereby controlling the peak value of the driving current I 1p Remain unchanged.

[0130] The above embodiments introduce a laser emission driving circuit when the laser in the light emitting device is anode driven. It should be noted that the laser emission driving scheme in the embodiments of this specification can also be applied to cathode driven lasers.

[0131] like Figure 9 The specific example circuit diagram of the laser emission drive circuit shown in FIG. 1 is different from the laser emission drive circuit of the anode-driven laser in that the drive control module 9A does not include a level shifter, and the transistor in the drive module U11 adopts an N-type field effect transistor, as shown in FIG. Figure 9 As shown, the driving module U11 includes: a fifth transistor LDN1, wherein a first electrode of the fifth transistor LDN1 is connected to the cathode of the laser LD, and a second electrode of the fifth transistor LDN1 is connected to the ground;

[0132] Correspondingly, the mirror feedback module U12 does not include a level shifter. The mirror feedback module U12 includes: a sixth transistor LDN2 and a first resistor R1, wherein the first resistor R1 forms a mirror structure with the laser LD; the first electrode of the sixth transistor LDN2 is coupled to the first resistor R1, the first electrode and the second electrode of the sixth transistor LDN2 are also connected to the inverting input terminal (-) of the voltage stabilizing unit U1, and the control electrode of the sixth transistor is connected to the output terminal of the voltage stabilizing unit U1.

[0133] In a specific implementation, the parameters of the corresponding components can be set according to the following proportional relationship:

[0134] I1=p*I2. To reduce DC loss, the value of p can be greater than 100. For example, an integer between 100 and 1000 or greater than 1000 can be selected as the value of p.

[0135] In addition, I1 = gm1 * (VA - Vth);

[0136] I2=(VDD2-VR) / R1;

[0137] V DAC =VR;

[0138] (VA-Vth)gm2=I2;

[0139] gm1=gm2*p;

[0140] Wherein, VA represents the output voltage of the voltage stabilizing unit, I1 represents the source current of the fifth transistor LDM1, that is, the driving current of the laser LD, I2 is the source current of the sixth transistor, gm2 is the transconductance of the sixth transistor LDM2, and represents the relationship between the gate-source voltage and the threshold voltage of the sixth transistor LDM2, VDD2 is the preset reference voltage, VR is the voltage between the gate and source of the sixth transistor LDM2, V DAC is the input voltage of the positive input terminal of the voltage stabilizing unit. When Vth changes with temperature (or other variables, such as process error), VR=V DAC , V DAC The invariance makes I2 unchanged with temperature, and the automatic adjustment of the feedback loop makes VA change with Vth. After VA changes, I1 remains approximately unchanged with temperature under the control of the drive pulse.

[0141] Although the embodiments of the present invention are disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A laser emission driving circuit, characterized in that: include: a drive control module configured to receive an input pulse signal and a digital control signal, and output a control level signal; wherein the digital control signal is used to adjust the magnitude of the control level signal output by the drive control module, and the pulse signal is used to control whether the drive control module outputs the control level signal; and a driving module connected to the driving control module and the power supply, configured to provide a driving current to the light-emitting device based on the control level signal to drive the light-emitting device to emit light, wherein the driving module adjusts the magnitude of the driving current based on the digital control signal; a mirror feedback module, connected to the drive control module and configured to provide a closed-loop feedback signal to the drive control module, wherein the closed-loop feedback signal is used to adjust the magnitude of the control level signal to offset the fluctuation of the drive current caused by the temperature drift of the drive module; In which, the driving control module includes a voltage stabilizing unit, which is suitable for outputting a stabilizing signal. The input end of the mirror feedback module is a port for outputting the stabilizing signal. The output end of the mirror feedback module is coupled to the input end of the voltage stabilizing unit. The mirror feedback module includes: the driving module and the mirror structure of the light-emitting device.

2. The laser emission driving circuit according to claim 1, characterized in that: The drive control module includes a digital-to-analog conversion unit; The digital-to-analog conversion unit is adapted to convert the digital control signal into an analog voltage signal and input the analog voltage signal into the voltage stabilization unit; The voltage stabilizing unit is adapted to receive the analog voltage signal and the closed-loop feedback signal.

3. The laser emission driving circuit according to claim 2, wherein: The drive control module further includes a switch unit, wherein: The voltage stabilizing unit is coupled to the switch unit and is adapted to perform a voltage stabilizing operation on the pulse signal input to the control terminal of the switch unit according to the voltage stabilizing signal; The switch unit is adapted to receive the pulse signal stabilized by the voltage stabilizing unit, determine whether to conduct the power supply of the driving module and the path between the switch unit and the ground according to the pulse signal, and provide the control level signal to the driving module when conducting.

4. The laser emission driving circuit according to claim 3, characterized in that: The light emitting device includes: a laser; the driving module includes: a first transistor, wherein: The control electrode of the first transistor is connected to the drive control module, the first electrode of the first transistor is connected to the power supply of the drive module, and the second electrode of the first transistor is connected to the anode of the laser; The drive control module also includes: a first level shifter, which is connected to the switch unit, the control electrode of the first transistor and the power supply of the drive module, suitable for providing a voltage drop, and outputting the control level signal based on the peak level of the pulse signal output by the switch unit to control the opening and closing of the first transistor.

5. The laser emission driving circuit according to claim 4, characterized in that: The mirror feedback module includes: a first resistor, a second transistor and a second level shifter, wherein: a first resistor, forming a mirror structure with the laser; a second transistor forming a mirror structure with the first transistor, wherein a first electrode of the second transistor is connected to a preset reference power supply, and a second electrode of the second transistor is connected to the first resistor; The second level shifter forms a mirror structure with the first level shifter, wherein the second level shifter is connected to the voltage stabilizing unit, the control electrode of the second transistor and the reference power supply, is suitable for providing a voltage drop, and controls the opening and closing of the second transistor based on the control level signal transmitted by the voltage stabilizing unit.

6. The laser emission driving circuit according to claim 5, characterized in that: The first level shifter includes: a third transistor and a second resistor, wherein: a control electrode of the third transistor is connected to the output end of the switch unit, and a first electrode of the third transistor is connected to the power supply of the driving module and to the control electrode of the first transistor through the second resistor; The second level shifter includes: a fourth transistor and a third resistor, wherein: a control electrode of the fourth transistor is connected to the output terminal of the voltage stabilizing unit, a first electrode of the fourth transistor is connected to the preset reference power supply and to the control electrode of the second transistor through the third resistor, and a second electrode of the fourth transistor is grounded; The resistance values ​​of the first resistor and the laser on-resistance, the resistance values ​​of the third resistor and the second resistor, the transconductance of the second transistor and the first transistor, and the transconductance of the fourth transistor and the third transistor are set so that the voltage difference between the control terminals of the second transistor and the first transistor is the same.

7. The laser emission driving circuit according to claim 6, characterized in that: The third resistor is an adjustable resistor, suitable for being adjusted based on the voltage of the regulated signal.

8. The laser emission driving circuit according to claim 3, characterized in that: The light emitting device includes a laser; The driving module includes: a fifth transistor, wherein a first electrode of the fifth transistor is connected to the cathode of the laser, and a second electrode of the fifth transistor is connected to the ground; The mirror feedback module includes: a sixth transistor and a first resistor, wherein the first resistor forms a mirror structure with the laser; the first electrode of the sixth transistor is coupled to the first resistor, the first electrode and the second electrode of the sixth transistor are also connected to the inverting input end of the voltage stabilizing unit, and the control electrode of the sixth transistor is connected to the output end of the voltage stabilizing unit.

9. The laser emission driving circuit according to any one of claims 2 to 8, characterized in that: The parameter ratio of the components between the voltage control terminal of the driving control module and the driving module and the light-emitting device to the corresponding components of the mirror feedback module is not less than 100.

10. The laser emission driving circuit according to claim 3, characterized in that: The voltage stabilizing unit includes: an operational amplifier, whose non-inverting input terminal is suitable for inputting the analog voltage signal, whose inverting input terminal is connected to the output terminal of the mirror feedback module, and whose voltage output terminal is connected to the switching unit and is suitable for outputting the regulated voltage signal; and / or The drive control module further includes: The narrow pulse generator is coupled to the switch unit and is adapted to generate a first narrow pulse based on the pulse signal, wherein the pulse width of the first narrow pulse is smaller than the pulse width of the input pulse signal.

11. A laser radar, characterized in that: include: A controller, a plurality of light-emitting devices, and a plurality of driving devices, wherein: The driving device comprises the laser emission driving circuit according to any one of claims 1 to 10; The plurality of light emitting devices are respectively coupled to corresponding driving devices and are adapted to emit light under the drive of the laser emission driving circuit; The controller is adapted to be coupled to the plurality of driving devices respectively, and is adapted to output a pulse signal and a digital control signal to the laser emission driving circuit to drive the corresponding light emitting device to emit light.

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