CN117673890A - Light-emitting driving circuit and laser radar - Google Patents

Abstract

The application provides a light-emitting driving circuit and a laser radar. The circuit comprises: a power regulating circuit and a driving circuit. A first output of the power conditioning circuit is coupled to a first input of the drive circuit. A second output of the drive circuit is for coupling with a laser. The power conditioning circuit includes: a first transistor and a second transistor coupled at different voltage sources. The drain of the first transistor and the drain of the second transistor are both coupled to the first output terminal. The driving circuit comprises a charge-discharge capacitor. The first end of the charge-discharge capacitor is coupled with the first input end, and the second end of the charge-discharge capacitor is grounded. The method and the device can simplify the driving circuit in the light-emitting driving circuit with larger peak power and pulse width.

Description

Light-emitting driving circuit and laser radar

Technical Field

The application relates to the technical field of laser radars, in particular to a light-emitting driving circuit and a laser radar.

Background

Lidar is an object detection technique. The laser is used as a signal light source, and the reflected signal of the target object is collected by emitting the laser to the target object, so that information such as the azimuth and the speed of the target object is obtained. The laser radar has the advantages of high measurement accuracy, strong anti-interference capability and the like, and is widely applied to the fields of remote sensing, measurement, intelligent driving, robots and the like.

In an actual application scenario or application environment, the lidar may need to dynamically adjust the power of the laser. In dynamic regulation, on the one hand, the laser radar needs to ensure that the peak power and pulse width of the laser pulse meet the requirements. On the other hand, a driving circuit for driving a laser in a lidar needs to be as compact as possible.

Therefore, how to simplify the driving circuit in the light-emitting driving circuit while ensuring that the peak power and the pulse width of the laser pulse meet the requirements is a problem to be solved.

Disclosure of Invention

The application provides a light-emitting driving circuit and a laser radar, so that the driving circuit in the light-emitting driving circuit with larger peak power and pulse width is simplified.

In a first aspect, the present application provides a light-emitting drive circuit. The circuit comprises: a power regulating circuit and a driving circuit. A first output of the power conditioning circuit is coupled to a first input of the drive circuit. A second output of the drive circuit is for coupling with a laser. The power conditioning circuit includes: a first transistor and a second transistor coupled at different voltage sources. The drain of the first transistor and the drain of the second transistor are both coupled to the first output terminal. The driving circuit comprises a charge-discharge capacitor. The first end of the charge-discharge capacitor is coupled with the first input end, and the second end of the charge-discharge capacitor is grounded.

In some possible implementations, when the first transistor is on, there may be a first drive signal at the first output; the second transistor may have a second drive signal at the first output when the second transistor is turned on.

The first driving signal and the second driving signal are used for charging the charge-discharge capacitor.

In some possible implementations, the voltage source may include a first voltage source and a second voltage source. The amplitude of the first voltage source is greater than the amplitude of the second voltage source, the source of the first transistor is coupled to the first voltage source, and the source of the second transistor is coupled to the second voltage source.

In some possible implementations, the power conditioning circuit may further include a gate drive circuit. An output of the gate drive circuit is coupled to the gate of the first transistor and the gate of the second transistor. The grid driving circuit is used for conducting the first transistor or the second transistor according to the input control signal. The first transistor is used for outputting a first voltage signal from a drain electrode of the first transistor when being conducted. The second transistor is used for outputting a second voltage signal from the drain electrode of the second transistor when being conducted. The amplitude of the first voltage signal is different from the amplitude of the second voltage signal.

In some possible embodiments, the first transistor may be turned on when the gate driving circuit inputs the first control signal; the second transistor may be turned on when the gate driving circuit inputs the second control signal.

In some possible implementations, the gate drive circuit may include a gate driver, a third transistor, and a first resistor. The third transistor is used for being turned on or turned off under the control of a control signal. The first resistor is used for outputting a third voltage signal to the input end of the gate driver when the third transistor is turned on; and outputting a fourth voltage signal to an input terminal of the gate driver when the third transistor is turned off. The amplitude of the third voltage signal and the amplitude of the fourth voltage signal are different.

In some possible implementations, the gate drive circuit may include an isolated gate driver. The isolated gate driver is used for turning on one of the first transistor and the second transistor according to the control signal.

In some possible implementations, the drive circuit may further include a second resistor. A first terminal of the second resistor is coupled to the first output terminal. The second terminal of the second resistor is coupled to the first input terminal.

In some possible implementations, the drive circuit may further include a first inductor. The first inductor is connected in parallel with the second resistor.

In a second aspect, the present application provides a lidar. The laser radar includes: a light-emitting drive circuit as in the first aspect and any possible implementation thereof; and the laser is coupled with the second output end of the light-emitting driving circuit.

The technical scheme that this application provided can include following beneficial effect:

in the present application, the power conditioning circuit includes different transistors coupled to different voltage sources, and these transistors output voltage signals with different magnitudes at the output end of the power conditioning circuit, so as to provide different voltages for the charge and discharge capacitors in the driving circuit in the charging stage; the charging and discharging capacitor in the driving circuit is independent of the power regulating circuit, and can drive the laser to emit light in the discharging stage. On one hand, the transistors in the power regulating circuit are selectively conducted, so that quick dynamic switching can be realized, and the peak power and the pulse width of the laser pulse of the laser can meet the requirements; on the other hand, the power regulating circuit can be decoupled from the driving circuit, so that the simplification of the driving circuit is ensured, and the area of a light-emitting loop formed by the driving circuit and the laser is reduced.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

Fig. 1 is a schematic structural diagram of a laser radar in the related art;

fig. 2 is a schematic diagram of a structure of a light-emitting driving circuit in the related art;

FIG. 3 is a schematic diagram of a light-emitting driving circuit according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of a gate driving circuit in an embodiment of the present application;

fig. 5 is a schematic structural diagram of another gate driving circuit according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a first implementation of a light-emitting driving circuit in an embodiment of the present application;

fig. 7 is a schematic structural diagram of a second implementation of a light-emitting driving circuit in an embodiment of the present application;

fig. 8 is a schematic structural diagram of a third implementation of a light-emitting driving circuit in an embodiment of the present application;

fig. 9 is a schematic structural diagram of a lidar according to an embodiment of the present application.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

In order to illustrate the technical solutions described in the present application, the following description is made by specific examples.

Lidar is an object detection technique. The laser radar emits laser beams through the laser, the laser beams are diffusely reflected after encountering a target object, the reflected beams are received through the detector, and the characteristic quantities such as the distance, the azimuth, the height, the speed, the gesture and the shape of the target object are determined according to the emitted beams and the reflected beams.

The application field of laser radar is very wide. In addition to its use in the military field, it is now widely used in the life field, including but not limited to: intelligent piloting vehicles, intelligent piloting airplanes, three-dimensional (3D) printing, virtual reality, augmented reality, service robots, and the like. Taking intelligent driving technology as an example, a laser radar is arranged in an intelligent driving vehicle, and the laser radar can scan the surrounding environment by rapidly and repeatedly emitting laser beams so as to acquire point cloud data reflecting the morphology, the position, the movement and the like of one or more target objects in the surrounding environment.

The intelligent driving technique may refer to unmanned, automatic, auxiliary, and the like.

Fig. 1 is a schematic structural diagram of a laser radar in the related art. Referring to fig. 1, the lidar 10 may include: a light emitting device 101, a light receiving device 102, and a processor 103. Wherein the light emitting device 101 and the light receiving device 102 are connected with the processor 103.

The connection relationship between the devices may be electrical connection or optical fiber connection. For example, in the light emitting device 101 and the light receiving device 102, it is also possible to include a plurality of optical devices, respectively, and the connection relationship between these optical devices is also possible to be a spatial light transmission connection.

The processor 103 is used to realize control of the transmitting device 101 and the light receiving device 102 so that the light transmitting device 101 and the light receiving device 102 can operate normally. Illustratively, the processor 103 may provide driving voltages for the light emitting device 101 and the light receiving device 102, respectively, and the processor 103 may also provide control signals for the light emitting device 101 and the light receiving device 102.

By way of example, the processor 103 may be a general-purpose processor such as a central processing unit (central processing unit, CPU), a network processor (network processor, NP), etc.; the processor 103 may also be a digital signal processor (digital signal processing, DSP), an application specific integrated circuit (application specific integrated circuit, ASIC), a field-programmable gate array (field-programmable gate array, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, or the like.

The light emitting device 101 further includes a light source (not shown) therein. It will be appreciated that the light source described above may refer to a laser, and that the number of lasers may be one or more. In an embodiment, the laser may be a pulsed laser diode (pulsed laser diode, PLD), semiconductor laser, fiber laser, or the like. The light source is used for emitting a laser beam. For example, the processor 103 may send an emission control signal to the light source, triggering the light source to emit a laser beam.

It will be appreciated that the laser beam may also be referred to as a laser pulse, laser, emitted beam, etc.

In an embodiment, the laser radar 10 may further include: one or more beam shaping optics and a beam scanning device (not shown). In one aspect, the beam shaping optics and beam scanning device focus and project the laser beam toward a particular location (e.g., an object) in the surrounding environment. In another aspect, the beam scanning device and the one or more shaping optics direct and focus the return wave beam onto the detector. A beam scanning device is employed in the optical path between the beam shaping optical element and the target object. The beam scanning device actually expands the field of view and increases the sampling density within the field of view of the lidar.

The following describes the detection of the object 104 by the lidar in a simplified manner in connection with the construction of the lidar shown in fig. 1.

Referring to fig. 1, the laser beam propagates in the emission direction, and when the laser beam encounters an object 104, it is reflected at the surface of the object 104, and the reflected beam is received by a light receiving device 102 of the laser radar. Here, the beam of the laser beam reflected back by the object 104 may be referred to as an echo beam (the laser beam and the echo beam are indicated by solid lines in fig. 1).

After the light receiving device 102 receives the echo beam, photoelectric conversion is performed on the echo beam, that is, the echo beam is converted into an electrical signal, the light receiving device 102 outputs the electrical signal corresponding to the echo beam to the processor 103, and the processor 103 can obtain the shape, position, moving point cloud data and the like of the object 104 according to the electrical signal of the echo beam.

In the related art, the laser in the above-described lidar needs to emit light under the drive of the light-emission drive circuit. The light emission driving circuit is generally classified into a charging circuit and a discharging circuit. When the light-emitting driving circuit drives the laser to emit light, the charging circuit firstly charges the charge-discharge capacitor until the voltage at two ends of the charge-discharge capacitor reaches a preset amplitude; then, the charge-discharge capacitor discharges to drive the laser to emit light.

In one known approach to a light emitting drive circuit, a boost circuit, such as a parallel switching converter (boost converter), is included in the charging circuit. The parallel switching converter can be used to charge a charge-discharge capacitance. However, due to the limitation of the characteristics of the associated switching converter, the adjustment range of the pulse width of the driving pulse of the laser is limited, and the peak power and the pulse width of the laser pulse cannot be ensured to meet the requirements, so that the light-emitting driving circuit cannot be suitable for all scenes.

Furthermore, in another known solution of the light-emitting driving circuit, the light-emitting driving circuit comprises a plurality of charge-discharge loops. Fig. 2 is a schematic diagram of a structure of a light-emitting driving circuit in the related art. As shown in fig. 2, the light-emitting driving circuit includes three charge-discharge circuits. Each charge-discharge loop includes a voltage source (e.g., any one of voltage source Va, voltage source Vb, and voltage source Vc), a diode Da, a charge-discharge capacitor C, a transistor T, a diode Db, and a light emitting diode Dc. The light emitting diode Dc is driven to emit light by one charge-discharge circuit at a time by the control signal outputted from the control unit 20. However, in the light emission driving circuit in this scheme, the charging circuit and the discharging circuit are not decoupled. In this way, when the charge-discharge capacitor C drives the light emitting diode Dc to emit light, the light emitting circuit including the charge-discharge capacitor and the light emitting diode Dc is complicated, and the area of the light emitting circuit is excessively large.

Therefore, how to simplify the driving circuit in the light-emitting driving circuit while ensuring that the peak power and the pulse width of the laser pulse meet the requirements is a problem to be solved.

In order to solve the above-described problems, embodiments of the present application provide a light emission driving circuit.

Fig. 3 is a schematic structural diagram of a light-emitting driving circuit in an embodiment of the present application. As shown in fig. 3, the light emission driving circuit 300 includes a power adjusting circuit 310 and a driving circuit 320.

Wherein the output terminal OUT1 (i.e., the first output terminal) of the power adjusting circuit 310 is coupled to the input terminal IN1 (i.e., the first input terminal) of the driving circuit 320. The output OUT2 (e.g., a second output) of the driver circuit 320 is configured to couple with the laser a. The driving circuit 320 includes a charge-discharge capacitance C. The first terminal of the charge-discharge capacitor C is coupled to the input terminal IN 1. The second end of the charge-discharge capacitor C is grounded. The power regulation circuit 310 further includes a transistor T1 (i.e., a first transistor) and a transistor T2 (i.e., a second transistor). The transistor T1 and the transistor T2 are coupled at different voltage sources. The drain of the transistor T1 and the drain of the transistor T2 are coupled to the output terminal OUT1.

It will be appreciated that the power adjustment circuit 310 is configured to generate a drive signal and the drive circuit 320 is configured to drive the laser a with the drive signal. Illustratively, the power conditioning circuit 310 outputs a drive signal at the output terminal OUT1, and the drive circuit 320 receives the drive signal at the input terminal IN 1.

In some possible implementations, the operation of the light-emitting driving circuit 300 may include two phases according to the operation state of the charge-discharge capacitor C: a charging phase and a discharging phase. IN the charging stage, one of the transistor T1 and the transistor T2 is turned on and generates a driving signal at the drain, which is output from the output terminal OUT1 to the input terminal IN1 and thereby charges the charge-discharge capacitance C. It can be understood that the maximum value of the voltage between the first terminal and the second terminal of the charge-discharge capacitor C is the amplitude of the driving signal at the input terminal IN 1. In the discharging stage, the charge-discharge capacitor C outputs a driving signal to the laser a through the output terminal OUT2, thereby driving the laser a to emit light.

It should be noted that the first terminal of the charge-discharge capacitor C is coupled to the input terminal IN1, and thus to the drain of the transistor T1 and the drain of the transistor T2; the second end of the charge-discharge capacitor C is grounded. In this way, during the discharge phase, the discharge loop formed by charge-discharge capacitor C and laser a (and possibly other circuit elements) is decoupled from power conditioning circuit 310.

In one embodiment, the transistors T1 and T2 may be field effect transistors (field effect transistor, FETs). Illustratively, the transistors T1 and T2 may be junction field effect transistors (jonction field effect transistor, JFET) and insulated gate field effect transistors by structure. Among them, insulated gate field effect transistors mostly refer to metal-oxide-semiconductor field effect transistors (MOSFETs). Of course, MOSFETs may be classified as enhancement MOSFETs or depletion MOSFETs.

It should be noted that the transistors T1 and T2 may be the same or different types of field effect transistors, which is not particularly limited in the embodiments of the present application.

In the embodiment of the present application, the field effect transistor is suitably applied to a high-sensitivity and low-noise circuit, and the transistor T1 and the transistor T2 can be rapidly (for example, nanosecond level) switched at the output terminal OUT1 under the driving of the gate driving circuit 311, so that the light emitting power of the laser can be rapidly adjusted.

In some possible implementations, when the transistor T1 is turned on, there may be a first drive signal at the output OUT 1; when the transistor T2 is turned on, a second driving signal may be present at the output terminal OUT 1. The first driving signal and the second driving signal are both used for charging the charge-discharge capacitor C.

It will be appreciated that since the transistor T1 and the transistor T2 are coupled to different voltage sources, respectively, the drive signals output by the transistors T1 and T2 to the output terminal OUT1 when turned on may be different (i.e., correspond to different voltage sources). When the transistor T1 is turned on, the driving signal output to the output terminal OUT1 is the first driving signal. When the transistor T2 is turned on, the driving signal output to the output terminal OUT1 is the second driving signal. The driving signal is used to output to the charge-discharge capacitor C through the output terminal OUT1, regardless of whether the driving signal is the first driving signal or the second driving signal, thereby charging the charge-discharge capacitor C.

In practical applications, the first drive signal and the second drive signal may have the same or different amplitudes, may have the same or different durations, and may also have the same or different repetition frequencies.

In some possible implementations, the voltage sources may include a voltage source V1 (i.e., a first voltage source) and a voltage source V2 (i.e., a second voltage source). The amplitude of the voltage source V1 is greater than the amplitude of the voltage source V2. The source of transistor T1 is coupled to a voltage source V1. The source of transistor T2 is coupled to a voltage source V2.

In practical applications, the amplitude values of the voltage source V1 and the voltage source V2 may be preset, so that the dynamic range of the optical signal emitted by the laser a may reach more than 10dB, thereby ensuring the linearity of the signal received by the receiving end. In one embodiment, the magnitude of voltage source V1 may be set to 20 volts (V) and the magnitude of voltage source V2 may be set to 6 volts (V). It should be noted that the voltage source V1 and the voltage source V2 may have any suitable amplitude, which is not specifically limited in the embodiments of the present application.

In some possible implementations, the power conditioning circuit 310 may also include a gate drive circuit 311. An output terminal of the gate driving circuit 311 is coupled to the gate of the transistor T1 and the gate of the transistor T2. The gate driving circuit 311 is configured to turn on the transistor T1 or the transistor T2 according to the input control signal SIG 1. The transistor T1 is configured to output a first voltage signal from a drain of the transistor T1 when turned on. The transistor T2 is configured to output a second voltage signal from the drain of the transistor T2 when turned on. The amplitude of the first voltage signal is different from the amplitude of the second voltage signal.

Obviously, since the drain of the transistor T1 and the drain of the transistor T2 are both coupled to the output terminal OUT1, the first voltage signal output from the drain of the transistor T1 is the first driving signal, and the second voltage signal output from the drain of the transistor T2 is the second driving signal.

In some possible embodiments, the gate driving circuit 311 is used to control the on and off of the transistors T1 and T2. An output terminal of the gate driving circuit 311 is coupled to the gate of the transistor T1 and the gate of the transistor T2. One of the transistors T1 and T2 is turned on and the other is turned off by a gate control signal outputted from an output terminal of the gate driving circuit 311. In one embodiment, the transistor T1 is turned on and the transistor T2 is turned off. In another embodiment, the transistor T1 is turned off and the transistor T2 is turned on.

Further, since the amplitude of the voltage source V1 is different from the amplitude of the voltage source V2, the amplitude of the first voltage signal output when the transistor T1 coupled to the voltage source V1 is turned on is different from the amplitude of the second voltage signal output when the transistor T2 coupled to the voltage source V2 is turned on. For example, in the case where the amplitude of the voltage source V1 is larger than the amplitude of the voltage source V2, the amplitude of the first voltage signal output when the transistor T1 coupled to the voltage source V1 is turned on is larger than the amplitude of the second voltage signal output when the transistor T2 coupled to the voltage source V2 is turned on.

In some possible embodiments, when the control signal SIG1 input by the gate driving circuit 311 is a first level value (i.e., a first control signal), the transistor T1 may be turned on; when the control signal SIG1 input from the gate driving circuit 311 is a second level value (i.e., a second control signal), the transistor T2 may be turned on.

It is understood that the control signal SIG1 may be one control signal having different levels. Or a combination of two independent sub-signals. Of course, the control signal SIG1 may take any other form, which is not particularly limited in the embodiment of the present application.

In some possible embodiments, the gate driving circuit 311 controls on and off of the transistors T1 and T2 under the action of the control signal SIG 1. To achieve such a function, the gate driving circuit 311 may realize its function in the following various ways, without being limited thereto.

In a first manner, fig. 4 is a schematic structural diagram of a gate driving circuit in an embodiment of the present application. As shown in fig. 4, the gate driving circuit 311 may include a gate driver GD, a transistor T3 (i.e., a third transistor), and a resistor R1 (i.e., a first resistor).

Illustratively, the transistor T3 may be an N-channel enhancement MOSFET (or referred to as an NMOS transistor). The gate of the transistor T3 inputs a control signal SIG1. The source of transistor T3 is grounded. The drain of transistor T3 is coupled to resistor R1. The resistor R1 may include a resistor R11 and a resistor R12. The first terminal of resistor R11 is coupled to a voltage source V1. A first terminal of resistor R12 is coupled to the drain of transistor T3. A second terminal of the resistor R11 and a second terminal of the resistor R12 are both coupled to an input terminal of the gate driver GD.

The transistor T3 is used to be turned on or off under the control of the control signal SIG1. The resistor R1 is used for outputting a third voltage signal to the input end of the gate driver GD when the transistor T3 is turned on; and outputs the fourth voltage signal to the input terminal of the gate driver GD when the third transistor T3 is turned off. The amplitude of the third voltage signal and the amplitude of the fourth voltage signal are different.

The gate driver GD is configured to output a gate control signal at an output terminal when receiving a voltage signal (e.g., a third voltage signal or a fourth voltage signal) at an input terminal thereof, so as to control on and off of the transistors T1 and T2. For example, the gate driver GD may control the transistor T1 to be turned on after receiving the third voltage signal; the gate driver GD may control the transistor T2 to be turned on after receiving the fourth voltage signal.

In one embodiment, the operation of the gate driving circuit is described based on the structure shown in fig. 4. When SIG1 is at a high level, transistor T3 is turned on, a third voltage signal is input at the input end of gate driver GD under the voltage division effect of resistor R11 and resistor R12, and a gate control signal corresponding to the third voltage signal is output at the output end of gate driver GD, and at this time, gate drive circuit 311 outputs the gate control signal; when SIG1 is low, transistor T3 is turned off, a fourth voltage signal is input to the input terminal of gate driver GD, and a gate control signal corresponding to the fourth voltage signal is output to the output terminal of gate driver GD, and at this time, gate drive circuit 311 outputs a gate control signal corresponding to the fourth voltage signal. Illustratively, if the magnitude of the third voltage signal is lower than the magnitude of the fourth voltage signal. The gate control signal output from the gate driving circuit 311 may be a low level signal corresponding to the third voltage signal or a high level signal corresponding to the fourth voltage signal.

In the embodiment of the present application, since the gate driver GD has a larger driving current, the gate driving circuit 311 including the gate driver GD can realize fast on and off of the transistor T1 and the transistor T2, thereby realizing fast switching of the amplitude of the driving signal.

In some possible embodiments, the circuit formed by the transistor T3, the resistor R11, and the resistor R12 may be referred to as a level shift circuit (or a level shift circuit). The function of the level shift circuit is to add a suitable dc bias to the signal input to the input of the gate driver GD to adapt to the reference levels of the gate driver GD, the transistor T1 and the transistor T2. For example, the reference level may include voltage sources to which the gate driver GD, the transistor T1, and the transistor T2 are respectively coupled.

In some possible implementations, the gate drive circuit 311 may include an isolated gate driver IGD. The isolated gate driver IGD is configured to turn on the transistor T1 or the transistor T2 according to a control signal.

Fig. 5 is a schematic structural diagram of another gate driving circuit in an embodiment of the present application. As shown in fig. 5, the gate drive circuit 311 may include an isolated gate driver IGD. The isolated gate driver IGD may replace the gate driver GD, the transistor T3, and the resistor R1 in fig. 5 and achieve the same function.

In practical applications, the gate driving circuit shown in fig. 5 can have a more compact circuit structure than the gate driving circuit shown in fig. 4 due to the use of the isolated gate driver IGD.

Still referring to fig. 3, the driving circuit 320 may further include a transistor T4 (i.e., a fourth transistor) in addition to the charge-discharge capacitor C. Alternatively, the transistor T4 may be a field effect transistor similar to the above-described transistors T1, T2, and T3. Illustratively, as shown in fig. 3, the transistor T4 may be an NMOS transistor. The gate of the transistor T4 inputs a control signal SIG2. The source of transistor T4 is grounded. The drain and the input terminal IN1 of the transistor T4 serve as two terminals of the output terminal OUT2, respectively, for connection to both ends of the laser a. The transistor T4 is turned off in the charge phase and turned on in the discharge phase under the control of the control signal SIG2 at the gate. Thus, in the discharging stage, the charge-discharge capacitor C, the transistor T4 and the laser a form a light emitting circuit to drive the laser a to emit light. In addition, it can be seen that the light emitting circuit is completely decoupled from the power conditioning circuit 310, and therefore can be sufficiently compact, reducing the area of the light emitting circuit.

In some possible implementations, the drive circuit may further include a resistor R2 (i.e., a second resistor). A first terminal of resistor R2 is coupled to output OUT 1. A second terminal of resistor R2 is coupled to input IN 1.

For example, a resistor R2 may be connected IN series between the output terminal OUT1 of the power adjusting circuit 310 and the input terminal IN1 of the driving circuit 320. In the charging phase, a resistor R2 is connected in series with a charge-discharge capacitor C. Thus, the resistor R2 can be used to adjust the charging speed of the charge-discharge capacitor C. When the resistance value of the resistor R2 is small, the charging current is large, the charging speed of the charging and discharging capacitor C is high, and the switching speed of the amplitude of the driving signal is high. When the resistance value of the resistor R2 is large, the charging current is small, the charging speed of the charging and discharging capacitor C is slow, and the switching speed of the amplitude of the driving signal is slow. In one embodiment, the transistor T1 or the transistor T2 receives the charging current, and the current passing capability of the transistor T1 or the transistor T2 needs to be considered to determine the resistance of the resistor R2.

In some possible implementations, the driving circuit 320 may further include an inductance L1 (i.e., a first inductance). The inductance L1 is connected in parallel with the resistance R2. It will be appreciated that the inductor L1 acts to reduce the dc impedance and thus eliminate the dc voltage drop in the charging loop.

In order that the gate driving circuit of the embodiment of the present application may be better understood, the following describes an example of the light emitting driving circuit in combination with a specific embodiment.

Fig. 6 is a schematic structural diagram of a first implementation of the light-emitting driving circuit in the embodiment of the present application. As shown in fig. 6, the light emitting driving circuit 600 may include a power adjusting circuit 610 and a driving circuit 620.

The light-emitting driving circuit 610 includes a transistor T1, a transistor T2, a gate driver GD, a transistor T3, a resistor R11, and a resistor R12. The source of transistor T1 is coupled to a voltage source V1. The source of transistor T2 is coupled to a voltage source V2. The drain of transistor T1 and the drain of transistor T2 are coupled to node N1. The gate of transistor T1 and the gate of transistor T2 are coupled to node N2. The first terminal of resistor R11 is coupled to a voltage source V1. The second terminal of the resistor R11 and the first terminal of the resistor R12 are both coupled to the input terminal of the gate driver GD. The second terminal of resistor R12 and the drain of transistor T3 are coupled to node N3. The gate of the transistor T3 is coupled to the control signal SIG 1. The source of transistor T3 is grounded. One input of the gate driver GD is coupled to the node N3. The output of the gate driver GD is coupled to the node N2. Further, the gate driver GD also has two input terminals. These two inputs are coupled to a voltage source V1 and a voltage source V2, respectively. The amplitude of the voltage source V1 is greater than the amplitude of the voltage source V2.

The driving circuit 620 may include a charge-discharge capacitor C and a transistor T4. The first terminal of the charge-discharge capacitor C is coupled to the node N1. The second end of the charge-discharge capacitor C is grounded. The gate of the transistor T4 is coupled to the control signal SIG 2. The source of transistor T4 is grounded. A first end of laser a is coupled to node N1. A second terminal of laser a is coupled to the drain of transistor T4.

In this embodiment, the transistor T1 is a PMOS transistor, and the transistors T2, T3, and T4 are NMOS transistors.

Based on the above configuration, the operation of the light-emitting driving circuit shown in fig. 6 will be described.

During the charging phase, the power conditioning circuit 610 operates as follows:

in the case where the control signal SIG1 input to the gate of the transistor T3 is high level, the transistor T3 is turned on. The third node N3 is low, and a low signal is input to the gate driver GD. The gate driver GD outputs a low-level signal to the node N2 and then inputs to the gate of the transistor T1 and the gate of the transistor T2. Transistor T1 is on and transistor T2 is off. The transistor T1 outputs a high level signal of the voltage source V1 to the node N1, and at this time, the first driving signal output from the power adjusting circuit 610 is a high level signal.

In the case where the control signal SIG1 input to the gate of the transistor T3 is low level, the transistor T3 is turned off. The third node N3 is at a high level, and a high level signal is input to the gate driver GD. The gate driver GD outputs a high level signal to the node N2 and then inputs to the gate of the transistor T1 and the gate of the transistor T2. Transistor T1 is off and transistor T2 is on. The transistor T2 outputs the low level signal of the voltage source V2 to the node N1, and at this time, the second driving signal output from the power adjusting circuit 610 is the low level signal.

In the charging phase, the driving circuit 620 operates as follows:

the control signal SIG2 has a low level, and the transistor T4 is turned off. In the case of having a high level at the node N1, the charge-discharge capacitance C is charged to the high level. In the case of having a low level at the node N1, the charge-discharge capacitance C is charged to the low level.

In the discharge phase, the driving circuit 620 operates as follows:

the control signal SIG2 has a high level, and the transistor T4 is turned on. Under the action of the voltage (namely the potential difference between the node N1 and the ground) between the charging and discharging capacitor C, the laser A is driven to emit light.

Up to this point, the light emission driving circuit shown in fig. 6 can realize switching between the level of the voltage source V1 and the level of the voltage source V2, thereby realizing switching of the laser a between high power and low power.

Fig. 7 is a schematic structural diagram of a second implementation of a light-emitting driving circuit in an embodiment of the present application. As shown in fig. 7, the light emission driving circuit 700 includes a power adjusting circuit 710 and a driving circuit 720.

The light-emitting driving circuit 710 includes a transistor T1, a transistor T2, and an isolated gate driver IGD. The source of transistor T1 is coupled to a voltage source V1. The source of transistor T2 is coupled to a voltage source V2. The drain of transistor T1 and the drain of transistor T2 are coupled to node N1. The gate of transistor T1 and the gate of transistor T2 are coupled to node N2. The three inputs of the isolated gate driver IGB are coupled to the control signal SIG1, the voltage source V1 and the voltage source V2, respectively. The output of the isolated gate driver IGB is coupled to node N2.

The driving circuit 720 includes a charge-discharge capacitance C and a transistor T4. The first terminal of the charge-discharge capacitor C is coupled to the node N4. The second end of the charge-discharge capacitor C is grounded. The gate of the transistor T4 is coupled to the control signal SIG 2. The source of transistor T4 is grounded. A first end of laser a is coupled to node N4. A second terminal of laser a is coupled to the drain of transistor T4.

The driving circuit 720 further includes a resistor R2 and an inductor L1. A first terminal of resistor R2 is coupled to first node N1. The second terminal of resistor R2 is coupled to a fourth node N4. A first terminal of the inductance L1 is coupled to the first node N1. The second terminal of the inductor L1 is coupled to the fourth node N4.

In this embodiment, the transistor T1 is a PMOS transistor, and the transistors T2 and T4 are NMOS transistors.

To this end, the light-emitting driving circuit shown in fig. 7 can realize switching between the level of the voltage source V1 and the level of the voltage source V2, similarly to the light-emitting driving circuit shown in fig. 6, thereby realizing switching of the laser a between high power and low power.

In some possible embodiments, the number of transistors in the power adjustment circuit may be further extended to be larger, so as to provide a driving signal with a larger power value for the driving circuit, so that the laser can be switched between a larger power, thereby expanding the dynamic adjustment range of the laser radar.

For example, assuming that the power adjusting circuit can output driving signals of 4 power values, fig. 8 is a schematic diagram of the structure of a third implementation of a light emitting driving circuit in the embodiment of the present application. As shown in fig. 8, the light emission driving circuit 800 includes a power adjusting circuit 810 and a driving circuit 820.

The light-emitting driving circuit 810 includes a transistor T1, a transistor T2, a gate driver GD, a transistor T3, a resistor R11 and a resistor R12, a transistor T5 (i.e., a fifth transistor), a transistor T6 (i.e., a sixth transistor), a transistor T7 (i.e., a seventh transistor), and a transistor T8 (i.e., an eighth transistor). The source of transistor T1 is coupled to a voltage source V1. The source of transistor T2 is coupled to a voltage source V2. The drain of transistor T1 and the drain of transistor T2 are coupled to node N5. The source of transistor T5 is coupled to a voltage source V3 (i.e., a third voltage source). The source of transistor T6 is coupled to a voltage source V4 (i.e., a fourth voltage source). The drain of transistor T5 and the drain of transistor T6 are coupled to node N6. The source of transistor T7 is coupled to node N5. The source of transistor T8 is coupled to node N6. The gate of the transistor T7 and the gate of the transistor T8 are both coupled to the control signal SIG3. The drain of transistor T7 and the drain of transistor T8 are both coupled to the first node N1. The gate of transistor T1, the gate of transistor T2, the gate of transistor T3, and the gate of transistor T4 are coupled to node N2. The first terminal of resistor R11 is coupled to a voltage source V1. The second terminal of the resistor R11 and the first terminal of the resistor R12 are both coupled to the input terminal of the gate driver GD. The second terminal of resistor R12 and the drain of transistor T3 are coupled to node N3. The gate of the resistor R12 transistor T3 is coupled to the control signal SIG 1. The source of transistor T3 is grounded. One input of the gate driver GD is coupled to the node N3. The output of the gate driver GD is coupled to the node N2. The gate driver also has two inputs. These two inputs are coupled to a voltage source V1 and a voltage source V2, respectively. The amplitude of the voltage source V1 is greater than the amplitude of the voltage source V2. The amplitude of voltage source V3 is greater than the amplitude of voltage source V4.

The driving circuit 820 includes a charge-discharge capacitance C and a transistor T4. The first terminal of the charge-discharge capacitor C is coupled to the node N4. The second end of the charge-discharge capacitor C is grounded. The gate of the transistor T4 is coupled to the control signal SIG 2. The source of transistor T4 is grounded.

The driving circuit 820 further includes a resistor R2 and an inductance L1. A first terminal of resistor R2 is coupled to first node N1. The second terminal of resistor R2 is coupled to a fourth node N4. A first terminal of the inductance L1 is coupled to the first node N1. The second terminal of the inductor L1 is coupled to the fourth node N4.

Further, the driving circuit 820 may further include a resistor R3 (i.e., a third resistor) and an inductor L2 (i.e., a second inductor). Here, the resistor R3 and the inductance L2 can also be understood as parasitic resistances and parasitic inductances in that circuit. The first end of the third resistor R3 is coupled to the drain of the transistor T4. The first end of the second inductance L2 is coupled to the fourth node N4.

The first end of the laser a is coupled to the second end of the second inductance L2. A second terminal of the laser a is coupled to a second terminal of the third resistor R3.

In this embodiment, the transistors T1, T5, and T7 may be PMOS transistors, and the transistors T2, T3, T4, T6, and T8 may be NMOS transistors.

Up to this point, the light emission driving circuit 810 shown in fig. 8 can realize switching between the levels of the voltage source V1, the voltage source V2, the voltage source V3, and the voltage source V4, thereby realizing switching of the laser a between a plurality of powers.

Specifically, in the light emission driving circuit 810, the level of one of the voltage source V1, the voltage source V2, the voltage source V3, and the voltage source V4 is output to the node N1 under the combined action of the control signals SIG1, SIG3 to form a driving signal.

On the one hand, the node N2 may be low level under the action of the control signal SIG 1. At this time, the transistors T1 and T5 are turned on, and the transistors T2 and T6 are turned off. The level of the voltage source V1 is output to the node N5. The level of the voltage source V3 is output to the node N6. Next, in the case where the control signal SIG3 is low level, the transistor T7 is turned on and the transistor T8 is turned off, and the level at the node N5 (i.e., the level of the voltage source V1) is output to the node N1; in the case where the control signal SIG3 is high level, the transistor T7 is turned off and the transistor T8 is turned on, and the level at the node N6 (i.e., the level of the voltage source V3) is output to the node N1.

On the other hand, the node N2 may be high level by the control signal SIG 1. At this time, the transistors T1 and T5 are turned off, and the transistors T2 and T6 are turned on. The level of the voltage source V2 is output to the node N5. The level of the voltage source V4 is output to the node N6. Next, in the case where the control signal SIG3 is low level, the transistor T7 is turned on and the transistor T8 is turned off, and the level at the node N5 (i.e., the level of the voltage source V2) is output to the node N1; in the case where the control signal SIG3 is high level, the transistor T7 is turned off and the transistor T8 is turned on, and the level at the node N6 (i.e., the level of the voltage source V4) is output to the node N1.

The light-emitting driving circuit in the embodiment of the present application may include a power supply circuit, or may receive an input power supply signal.

In the embodiment of the application, the power regulating circuit comprises different transistors coupled to different voltage sources, and the transistors output voltage signals with different amplitudes at the output end of the power regulating circuit, so that charge and discharge capacitors in the driving circuit are charged to different amplitudes in a charging stage; the charging and discharging capacitor in the driving circuit is independent of the power regulating circuit, and can drive the laser to emit light in the discharging stage. On one hand, the transistors in the power regulating circuit are selectively conducted, so that quick dynamic switching can be realized, and the peak power and the pulse width of the laser pulse of the laser can meet the requirements; on the other hand, the power regulating circuit can be decoupled from the driving circuit, so that the simplification of the driving circuit is ensured, and the area of a light-emitting loop formed by the driving circuit and the laser is reduced.

Based on the same inventive concept, the embodiment of the application also provides a laser radar. Fig. 9 is a schematic structural diagram of a lidar according to an embodiment of the present application. As shown in fig. 9, the lidar 900 includes: a light-emitting drive circuit 901 as described in one or more embodiments above; laser a. The laser a is coupled to the output of the light emission drive circuit 901.

It will be understood by those skilled in the art that the sequence number of each step in the above embodiment does not mean that the execution sequence of each process should be determined by the function and the internal logic, and should not limit the implementation process of the embodiment of the present invention.

The above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; while the invention has been described in detail with reference to the foregoing embodiments, it will be appreciated by those skilled in the art that variations may be made in the techniques described in the foregoing embodiments, or equivalents may be substituted for elements thereof; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention, and are intended to be included in the scope of the present invention.

Claims (10)

1. A light-emitting drive circuit, characterized by comprising: the laser comprises a power adjusting circuit and a driving circuit, wherein a first output end of the power adjusting circuit is coupled with a first input end of the driving circuit, and a second output end of the driving circuit is used for being coupled with a laser;

the power conditioning circuit includes: a first transistor and a second transistor coupled at different voltage sources, the drain of the first transistor and the drain of the second transistor both being coupled to the first output;

The driving circuit includes: and the first end of the charge-discharge capacitor is coupled with the first input end, and the second end of the charge-discharge capacitor is grounded.

2. The light-emitting driver circuit according to claim 1, wherein the first output terminal has a first drive signal when the first transistor is turned on; when the second transistor is conducted, a second driving signal is arranged at the first output end, and the first driving signal and the second driving signal are used for charging the charge-discharge capacitor.

3. The light-emitting driver circuit of claim 1, wherein the voltage source comprises:

a first voltage source and a second voltage source, the first voltage source having a magnitude greater than a magnitude of the second voltage source, a source of the first transistor coupled to the first voltage source, and a source of the second transistor coupled to the second voltage source.

4. The light-emitting driver circuit according to claim 1, wherein the power adjustment circuit further comprises: a gate drive circuit, an output of which is coupled to the gate of the first transistor and the gate of the second transistor;

The grid driving circuit is used for conducting the first transistor or the second transistor according to an input control signal;

the first transistor is used for outputting a first voltage signal from the drain electrode of the first transistor when being conducted; the second transistor is used for outputting a second voltage signal from the drain electrode of the second transistor when being conducted; the amplitude of the first voltage signal is different from the amplitude of the second voltage signal.

5. The light-emitting driver circuit according to claim 4, wherein the first transistor is turned on when the gate driver circuit inputs a first control signal; when the gate driving circuit inputs a second control signal, the second transistor is turned on.

6. The light-emitting driver circuit according to claim 4, wherein the gate driver circuit comprises: a gate driver, a third transistor, and a first resistor;

the third transistor is used for being turned on or turned off under the control of the control signal;

the first resistor is used for outputting a third voltage signal to the input end of the gate driver when the third transistor is turned on, and outputting a fourth voltage signal to the input end of the gate driver when the third transistor is turned off; the amplitude of the third voltage signal and the amplitude of the fourth voltage signal are different.

7. The light-emitting driver circuit according to claim 4, wherein the gate driver circuit comprises: and the isolated gate driver is used for conducting one of the first transistor and the second transistor according to the control signal.

8. The light-emitting driver circuit according to claim 1, wherein the driver circuit further comprises: and a second resistor, a first end of the second resistor being coupled to the first output terminal, and a second end of the second resistor being coupled to the first input terminal.

9. The light-emitting driver circuit of claim 8, wherein the driver circuit further comprises: and the first inductor is connected with the second resistor in parallel.

10. A lidar, comprising:

the light-emitting drive circuit according to any one of claims 1 to 9;

and the laser is coupled with the second output end of the light-emitting driving circuit.