Driving device and method for laser radar light emitting device and laser radar

Abstract

The present invention provides a driving device and method for a laser radar light-emitting device, and a laser radar including the driving device. The driving device includes: an inverting module, whose input end is connected to a pulse voltage signal and an adjustable level, and outputs a first intermediate level signal, which is inverted to the pulse voltage signal; an isolation capacitor, which receives the first intermediate level signal and outputs a second intermediate level signal; and a driving module, which receives the second intermediate level signal and provides a driving current to the light-emitting device to drive the light-emitting device to emit light, wherein the driving current is adjusted according to the adjustable level. The solution of the present invention can achieve direct control of the driving current of the light-emitting device used for the laser radar, and the circuit design is relatively simple, the current transmission path is short, and the response speed is fast.

Description

Technical Field

[0001] The present invention relates to the field of laser radar, and more specifically, to a driving device and a driving method for a laser radar light-emitting device, and a laser radar including the driving device. 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. Figure 1 FIG. 1 is a schematic diagram showing the working principle of an exemplary laser radar 100. Figure 1 As shown in FIG, the laser radar 100 is, for example, a 16-line laser radar, which can be along Figure 1 16 laser beams, L1, L2, ..., L15, L16, are emitted in the vertical direction of the laser radar 100. Each laser beam corresponds to a channel of the laser radar 100, with a total of 16 channels for detecting the surrounding environment. During the detection process, the laser radar 100 can rotate along its vertical axis. During the rotation, the light emitting device ( Figure 1 (not shown) laser beams L1, L2, ..., L15, L16 are emitted through each channel in sequence according to a certain time interval (for example, 1 microsecond) and detected, thereby completing a line scan on the vertical field of view. Afterwards, the laser radar 100 performs the next line scan of the vertical field of view at a certain angle (for example, 0.1 degrees or 0.2 degrees) in the horizontal field of view. The receiver of the laser radar 100 can receive the echo reflected back after the laser beam emitted by each channel encounters an obstacle, and detect the distance and direction of the obstacle (or a point on the obstacle) by calculating the round-trip flight time of the laser beam, thereby forming point cloud data. Multiple detections are performed during the entire rotation process of the laser radar 100 to form point cloud data of the obstacle, thereby sensing the conditions of the surrounding environment.

[0003] For example, Figure 1 The 16-channel laser radar 100 shown rotates one circle (360 degrees) to scan and detect, which can form a frame of point cloud data. The laser radar 100 continuously rotates and scans to detect, which can form multiple frames of point cloud data. Figure 1 The laser radar 100 in the figure is only an example used to illustrate the working principle of the laser radar, and the laser beams do not have to be uniformly distributed in the vertical direction.

[0004] As can be seen from the operating principle of LiDAR described above, the LiDAR's light-emitting device is a crucial component of the entire LiDAR system, requiring consistent and stable light energy across temperatures, batches, and channels. Currently, the design of the driver circuit for LiDAR's light-emitting device is a major challenge in LiDAR circuit implementation.

[0005] In actual applications, since the distance and reflectivity of the target detected by the laser radar are constantly changing, the light intensity of the light-emitting device is required to be able to be adjusted quickly accordingly, which puts higher requirements on the driving circuit of the light-emitting device.

[0006] Figure 2 FIG. 1 shows a schematic diagram of a driving circuit for a laser radar light emitting device in the prior art. Figure 2 As shown, the driving circuit includes devices M0 to M5, wherein M0 to M3 are high-voltage NMOS devices, and M4 to M5 are high-voltage PMOS devices. Figure 2 In the driver circuit shown, M0 to M3 form a typical NMOS current mirror circuit, and M4 to M5 form a typical PMOS current mirror circuit. By controlling the device dimensions (such as the aspect ratio) of M0 to M5, a current ratio of 1:K1:K2:K3:KN can be easily achieved.

[0007] like Figure 2 As shown in , assuming the input current source of the driver circuit is I1, the maximum output current (i.e., the input current of light-emitting device D1) is KN*I1*(K1+K2+K3) / K3, and the minimum is KN*I1 / K3. Resistor R2 controls the gate-source voltage of PMOS transistors M4 and M5, and S1 and S1N, S2 and S2N, and S3 and S3N are three pairs of mutually exclusive switches. Mutually exclusive switches refer to switches that, in the same state, one switch is on and the other is off.

[0008] In such Figure 2 In the prior art solution shown, the output current is adjusted by controlling the states of switches S1 and S1N; S2 and S2N; and S3 and S3N. Because the current mirror circuit requires step-by-step current conversion, its response speed is slow, making it difficult to achieve precise nanosecond current control. Furthermore, the circuit is relatively complex, with large parasitic capacitance and resistance in the nodes, which can significantly interfere with the circuit. Summary of the Invention

[0009] In response to the above problems, the present invention proposes a driving device and a driving method for a laser radar light-emitting device that eliminates the current mirror structure, as well as a laser radar including the driving device.

[0010] According to one aspect of the present invention, a driving device for a laser radar light-emitting device is provided. The driving device includes: an inverting module, whose input is connected to a pulse voltage signal and an adjustable voltage level, and outputs a first intermediate-level signal that is inverted from the pulse voltage signal; an isolation capacitor, which receives the first intermediate-level signal and outputs a second intermediate-level signal; and a driving module, which receives the second intermediate-level signal and provides a driving current to the light-emitting device to drive the light-emitting device to emit light, wherein the driving current is adjusted according to the adjustable voltage level.

[0011] In one embodiment, the inverting module includes a first transistor and a second transistor, and the first poles of the first transistor and the second transistor are both connected to the input pulse voltage signal, the second pole of the first transistor is connected to the adjustable level, the third pole of the first transistor is connected to the third pole of the second transistor, and the second pole of the second transistor is grounded.

[0012] In one embodiment, the driving module includes a third transistor, and wherein the first pole of the third transistor is connected to the second intermediate level signal, the second pole of the third transistor is connected to the power supply voltage of the driving module, and the third pole of the third transistor is connected to the light-emitting device of the laser radar to provide the driving current to the light-emitting device.

[0013] In one embodiment, the first transistor is a PNP transistor or a PMOS transistor, and the second transistor is an NPN transistor or an NMOS transistor.

[0014] In one embodiment, the third transistor is a PNP transistor or a PMOS transistor.

[0015] In one embodiment, the high potential of the pulse voltage signal is the first potential, and the low potential is the second potential; the high potential of the first intermediate level signal output by the inversion module is determined by the adjustable level, and the low potential is the second potential.

[0016] In one embodiment, an input end of the isolation capacitor is connected to the third electrode of the first transistor and the third electrode of the second transistor to receive the first intermediate level signal, and an output end of the isolation capacitor outputs the second intermediate level signal to the driving module, wherein the second intermediate level signal is in phase with the first intermediate level signal, and a high potential of the second intermediate level signal is the power supply voltage of the driving module, and a low potential of the second intermediate level signal is the difference between the power supply voltage of the driving module and the adjustable level.

[0017] In one embodiment, the driving module further includes a first resistor and at least one diode connected in parallel between the output terminal of the isolation capacitor and the power supply voltage of the driving module.

[0018] In one embodiment, the at least one diode includes a first diode, and a cathode of the first diode is connected to the power supply voltage of the driving module, and an anode of the first diode is connected to the second intermediate level signal to limit the second intermediate level signal.

[0019] In one embodiment, the at least one diode includes a second diode, and the anode of the second diode is connected to the power supply voltage of the driving module, and the cathode of the second diode is connected to the second intermediate level signal for charging the second intermediate level signal when the third transistor is turned off.

[0020] In one embodiment, the maximum value of the driving current is determined based on the power supply voltage of the driving module, the intrinsic parameters of the third transistor, the parasitic resistance of the light-emitting device, and the second intermediate level signal.

[0021] In one embodiment, the second intermediate level signal is determined by the power supply voltage of the driving module and the adjustable level.

[0022] In one embodiment, the driving device further includes: a stabilizing transformer module configured to receive an input of an adjustable voltage source and output the adjustable level, so that when the adjustable voltage source is adjusted, the adjustable level is stably adjusted along with the adjustable voltage source.

[0023] In one embodiment, the voltage stabilization and transformation module includes a low dropout linear regulator (LDO).

[0024] In one embodiment, the pulse voltage signal is a short pulse signal.

[0025] According to another aspect of the present invention, a laser radar is provided, comprising: a driving device as described above; and a light-emitting device of the laser radar, the light-emitting device comprising a parasitic resistance, a parasitic inductance and a light-emitting device connected in series to the third electrode of the third transistor, and the parasitic resistance and parasitic inductance in series are connected to the high-end side of the light-emitting device, and the low-end side of the light-emitting device is grounded.

[0026] In one embodiment, the light emitting device includes an edge emitting laser (EEL) or a vertical cavity surface emitting laser (VCSEL).

[0027] According to another aspect of the present invention, a method for driving a laser radar light-emitting device is provided, employing the laser radar described above. The method comprises: utilizing an inverting module to receive an input pulse voltage signal and an adjustable level and outputting a first intermediate level signal, the first intermediate level signal being inversely proportional to the pulse voltage signal; utilizing an isolation capacitor to receive the first intermediate level signal and outputting a second intermediate level signal to a driving module; and utilizing the driving module to provide a driving current to the light-emitting device to drive the light-emitting device to emit light, wherein the driving current is adjusted by adjusting the adjustable level.

[0028] In one embodiment, the high potential of the pulse voltage signal is the first potential, and the low potential is the second potential; the high potential of the first intermediate level signal output by the inversion module is determined by the adjustable level, and the low potential is the second potential.

[0029] The solution of the present invention simplifies the circuit structure of the driving device of the light-emitting device of the laser radar, reduces the various parasitic resistances, parasitic capacitances and other problems caused by the complexity of the circuit, and since the driving current can be adjusted without step-by-step accumulation, direct control of the driving current is achieved, making the adjustment speed faster and easily achieving nanosecond (ns) level control. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram illustrating the working principle of an exemplary laser radar is shown;

[0031] Figure 2 A schematic diagram of a driving circuit for a laser radar light emitting device in the prior art is shown;

[0032] Figure 3 A schematic structural diagram of a laser radar according to an embodiment of the present invention is shown;

[0033] Figure 4 Shown for Figure 3 A schematic diagram of a driving device of a light emitting device of the laser radar shown;

[0034] Figure 5 A schematic diagram of signal waveforms of a driving device according to an embodiment of the present invention is shown;

[0035] Figure 6 Shown Figure 4 A schematic diagram of an embodiment of a drive device shown;

[0036] Figure 7 A schematic structural diagram showing a stable voltage transformation module that can be used in a drive device according to an embodiment of the present invention is shown; and

[0037] Figure 8 Shown Figure 4A schematic diagram of another embodiment of a drive device is shown. DETAILED DESCRIPTION

[0038] The following will describe in detail various embodiments of the present invention in conjunction with the accompanying drawings to provide a clearer understanding of the objectives, features and advantages of the present invention. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solution of the present invention.

[0039] In the following description, for the purpose of illustrating the various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details. In other cases, well-known devices, structures, and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0040] Unless the context requires otherwise, throughout the specification and claims, the word "comprise" and variations such as "include" and "have" should be construed in an open, inclusive sense, that is, should be interpreted to mean "including, but not limited to."

[0041] Reference throughout this specification to "one embodiment" or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of "in one embodiment" or "some embodiments" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.

[0042] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "and / or" unless the context clearly dictates otherwise.

[0043] The inventive concept of the present invention is to use direct control to control the driving current output to the light-emitting device of a laser radar, instead of a step-by-step current conversion method. Specifically, the driver of the laser radar light-emitting device of the present invention can input a low-voltage adjustable voltage level (V2), and by adjusting this adjustable voltage level, the output current of the driver (i.e., the driving current of the light-emitting device) can be adjusted.

[0044] Figure 3 FIG. 1 shows a schematic structural diagram of a laser radar 1 according to an embodiment of the present invention. Figure 3As shown in FIG, the laser radar 1 includes a light emitting device 20 and a driving device 10 for providing a driving current Id to the light emitting device 20. The light emitting device 20 includes a parasitic resistor 22, a parasitic inductor 24, and a light emitting device 26 connected in series, wherein the parasitic resistor 22 and the parasitic inductor 24 are connected in series on the power supply side (i.e., the high side) of the light emitting device 26, and the low side of the light emitting device 26 is grounded (GND). Since the driving current Id of the driving device 10 is injected into the light emitting device 26 from the power supply side of the light emitting device 26, Figure 2 The structure shown can also be called a high-side driven laser radar light-emitting device. Those skilled in the art will understand that for the sake of simplicity, only the light-emitting device and its driver portion of the laser radar 1 are shown here, while other parts of the laser radar 1, such as the receiver, are omitted.

[0045] In some embodiments, the light emitting device 26 may be an edge emitting laser (EEL) or a vertical cavity surface emitting laser (VCSEL), among others.

[0046] Figure 4 Shown for Figure 3 Schematic diagram of the driving device 10 of the light emitting device 20 of the laser radar 1 shown. Figure 4 As shown in FIG, the driving device 10 may include an inverting module 12, whose input is connected to the pulse voltage signal Vin and an adjustable voltage level V2, and outputs a first intermediate level signal Vy. The inverting module 12 causes the output first intermediate level signal Vy to be inverted with respect to the input pulse voltage signal Vin. Specifically, when the input pulse voltage signal Vin is at a high level, the output first intermediate level signal Vy is at a low level; when the input pulse voltage signal Vin is at a low level, the output first intermediate level signal Vy is at a high level.

[0047] The high level of the pulse voltage signal Vin and the high level of the first intermediate level signal Vy may have different values.

[0048] Preferably, according to the solution of this embodiment, the high level of the first intermediate level signal Vy is determined by the adjustable level V2. For example, the high level of the pulse voltage signal Vin is the power supply voltage VDD of the signal generator, and the high level value of the first intermediate level signal Vy is the adjustable voltage V2.

[0049] More preferably, the low level of the pulse voltage signal Vin and the low level of the first intermediate level signal Vy are both 0V.

[0050] Figure 5 FIG. 1 shows a schematic diagram of signal waveforms of a driving device according to an embodiment of the present invention. Figure 5As shown, using the inverting module 12, when the input signal Vin is at a low potential (e.g., 0V), the output signal Vy is at a high potential (e.g., adjustable level V2); conversely, when the input signal Vin is at a high potential (e.g., VDD), the output signal Vy is at a low potential (e.g., 0V). Those skilled in the art will appreciate that the above-mentioned high and low potential settings of the pulse voltage signal Vin are merely exemplary, and the present invention is not limited to the above-mentioned specific settings, and other high and low potential settings may be used.

[0051] In one embodiment, the pulse voltage signal Vin can be a short pulse signal, that is, the duration of the high potential (Tpulse) is much shorter than the duration of the low potential. Figure 6 and Figure 8 Provide a detailed description.

[0052] The driving device 10 further includes an isolation capacitor 14, which is used to receive the first intermediate level signal Vy from the inverting module 12 and output a second intermediate level signal Vx. The second intermediate level signal Vx is in phase with the first intermediate level signal Vy, and the level of the second intermediate level signal Vx depends on the level of the first intermediate level signal Vy. However, due to the influence of the load, the levels of the two may be different. In one embodiment, Figure 5 As shown in , when the first intermediate level signal Vy is at a high potential, and the level value is an adjustable level V2, the output second intermediate level signal Vx is also at a high potential, and the level value is the power supply voltage VDD1 of the driving module 16; conversely, when the first intermediate level signal Vy is at a low potential, and the level value is 0V, the second intermediate level signal Vx is also at a low potential, and the level value is VDD1-V2.

[0053] The driving module 16 of the driving device 10 receives the second intermediate-level signal Vx and provides a driving current Id to the light-emitting device 20, causing the light-emitting device 20 to emit light. The magnitude of the driving current Id depends on the magnitude of the second intermediate-level signal Vx. Therefore, if the hardware composition of the entire driving device 10 is fixed, the driving current Id can be adjusted by adjusting the adjustable level V2.

[0054] In order to achieve precise control of the adjustable level V2, in one embodiment, the driving device 10 may further include a stabilizing transformer module 17, which is configured to receive the reference level VREF of the adjustable voltage source 18 and maintain the output adjustable level V2 in a stable manner when the adjustable voltage source 18 is adjusted. In other words, the stabilizing transformer module 17 is used to achieve the conversion from the level VREF to the level V2, where the transmission coefficient is K, K = V2 / VREF. In this way, the adjustable level V2 can be obtained by adjusting the adjustable voltage source 18. The specific embodiment of the stabilizing transformer module 17 will be described below in conjunction with Figure 7 Provide a detailed description.

[0055] In addition, the driving device 10 may further include one or more power supply modules (not shown) to respectively provide the high potential VDD of the pulse voltage signal Vin, the power supply voltage VDD1 of the driving module 16 and the power supply voltage VDD2 of the adjustable voltage source 18 .

[0056] Figure 6 Shown Figure 4 A schematic diagram of an embodiment of a drive device 10 is shown.

[0057] In such Figure 6 In the illustrated embodiment, the inverting module 12 may include a first transistor 122 and a second transistor 124. A first electrode of each of the first transistor 122 and the second transistor 124 is connected to the pulse voltage signal Vin, a third electrode of the first transistor 122 is connected to a third electrode of the second transistor 124 to output a first intermediate level signal Vy to the isolation capacitor 14, a second electrode of the first transistor 122 is connected to the adjustable voltage V2, and a second electrode of the second transistor 124 is grounded (GND).

[0058] The driving module 16 may include a third transistor 162, wherein the first electrode of the third transistor 162 receives the second intermediate level signal Vx from the isolation capacitor 14, the second electrode of the third transistor 162 is connected to the power supply voltage VDD1 of the driving module 16, and the third electrode of the third transistor 162 is connected to the light-emitting device 20 of the laser radar 1, for providing a driving current Id to the light-emitting device 20.

[0059] The input terminal of the isolation capacitor 14 is connected to the third electrode of the first transistor 122 and the third electrode of the second transistor 124 to receive the first intermediate level signal Vy. The output terminal of the isolation capacitor 14 outputs the second intermediate level signal Vx to the driving module 16. For the sake of convenience, the two ends of the isolation capacitor 14 are referred to as the input terminal and the output terminal from the perspective of the direction of voltage influence in the circuit structure. In fact, under normal circumstances, the two ends of the isolation capacitor 14 are not specifically distinguished.

[0060] use Figure 6 In the illustrated driving device 10, the inverting module 12 continuously inputs a low voltage adjustable level V2. When the input pulse voltage signal Vin is at a low potential (e.g., 0V), the first transistor 122 is turned on and the second transistor 124 is turned off, resulting in the first intermediate level signal Vy being at the adjustable level V2, the second intermediate level signal Vx being at the power supply voltage VDD1 of the driving module 16, and the voltage difference across the isolation capacitor 14 being VDD1-V2. When the input pulse voltage signal Vin changes to a high potential VDD, the first transistor 122 is turned off and the second transistor 124 is turned on. The first intermediate level signal Vy and the second transistor 124 are grounded, reaching 0V. The voltage across the isolation capacitor 14 changes equidistantly, and the second intermediate level signal Vx becomes VDD1-V2. Therefore, by adjusting the adjustable level V2, the change of the second intermediate level signal Vx can be adjusted, thereby affecting the equivalent resistance Rdson of the third transistor 162, thereby adjusting the driving current Id.

[0061] In such Figure 6 In the illustrated embodiment, the first transistor 122 may be a PMOS transistor (more specifically, a high-voltage PMOS transistor), the second transistor 124 may be an NMOS transistor (more specifically, a high-voltage NMOS transistor), and in the specification, the first electrode corresponds to the gate (G), the second electrode corresponds to the source (S), and the third electrode corresponds to the drain (D).

[0062] In addition, the third transistor 162 can be a PMOS tube (more specifically, a high-voltage PMOS tube), and the first electrode corresponds to the gate (G), the second electrode corresponds to the source (S), and the third electrode corresponds to the drain (D) in the specification.

[0063] Here, the MOS tube refers to a MOSFET, namely a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), the PMOS tube refers to a P-channel MOS tube, and the NMOS tube refers to an N-channel MOS tube.

[0064] In addition, in some embodiments, the driving module 16 may further include a first resistor 164 and at least one diode (diode 166 and / or 168 ) connected in parallel between the output end of the isolation capacitor 14 and the power supply voltage ( VDD1 ) of the driving module 16 .

[0065] In one embodiment, the at least one diode includes a first diode 166, wherein the negative electrode of the first diode 166 is connected to the power supply voltage VDD1 of the driving module 16, and the positive electrode of the first diode 166 is connected to the second intermediate level signal Vx to limit the second intermediate level signal Vx. With the first diode 166, the level value of the second intermediate level signal Vx is limited to Vx < VDD1 + Vth1, where Vth1 is the conduction voltage threshold of the first diode 166.

[0066] Optionally or additionally, the at least one diode includes a second diode 168, wherein the positive electrode of the second diode 168 is connected to the power supply voltage VDD1 of the driving module 16, and the negative electrode of the second diode 168 is connected to the second intermediate level signal Vx to charge the second intermediate level signal Vx when the third transistor 162 is turned off.

[0067] As Figure 5 shown, in Figure 4 the embodiment shown, the minimum value of the driving current Id is 0, and the maximum value of the driving current Id is Imax. In an embodiment according to the present invention, the maximum value Imax of the driving current Id is determined by the power supply voltage VDD1 of the driving module 16, the on-resistance Rdson of the driving module 16, and the parasitic resistance 22 of the light-emitting device 20. For example, the maximum value Imax of the driving current Id can be expressed by the following formula (1):

[0068] Imax = VDD1 / (R1 + Rdson), (1)

[0069] where R1 is the resistance value of the parasitic resistance 22 of the light-emitting device 20, and Rdson is the on-resistance of the driving module 16.

[0070] Furthermore, the on-resistance Rdson of the driving module 16 is determined by the inherent parameters of the third transistor 162 and the second intermediate level signal Vx. For example, in the embodiment as Figure 6 shown, the on-resistance Rdson of the driving module 16 can be expressed by the following formula (2):

[0071]

[0072] where, W is the channel width of the third transistor 162, L is the channel length of the third transistor 162, Vth is the conduction threshold of the third transistor 162, and they are all inherent parameters of the third transistor 162, and k is a constant. Here, those skilled in the art can know that the constant k is a constant determined by the properties of silicon-based devices and depends on Planck's constant.

[0073] Therefore, in the embodiment as Figure 6In the illustrated embodiment, the maximum value Imax of the driving current may be determined based on the power supply voltage VDD1 of the driving module 16 , intrinsic parameters of the third transistor 162 , the parasitic resistance 22 of the light emitting device 20 , and the second intermediate level Vx.

[0074] As mentioned above and as Figure 5 As shown in , the second intermediate level Vx is determined by the power supply voltage VDD1 and the adjustable level V2 of the driving module 16. That is, when the hardware components of the driving device 10 and the light-emitting device 20 remain unchanged, the maximum value of the driving current Id can vary with the input adjustable level V2.

[0075] In summary, by using the driving device 10 according to an embodiment of the present invention, a short pulse current signal Id can be obtained as the driving current provided to the light-emitting device 20 by inputting a short pulse voltage signal Vin and an adjustable level V2, and by adjusting the level value of the input adjustable level V2, the maximum value Imax of the output driving current Id can be conveniently adjusted.

[0076] Therefore, the stable voltage transformation module 17 for accurately adjusting the adjustable voltage level V2 is very important for adjusting the magnitude of the driving current Id.

[0077] In one embodiment, the voltage stabilization and transformation module 17 may include a low dropout linear regulator (LDO). The LDO may operate in a low voltage domain to output a low voltage domain control signal V2.

[0078] Figure 7 FIG. 1 shows a schematic structural diagram of a stabilizing voltage transformation module 17 that can be used in a driving device 10 according to an embodiment of the present invention.

[0079] like Figure 7 As shown in FIG, the voltage stabilization module 17 includes an error amplifier 172, a driver stage 174, an output stage 176, and a feedback loop 178. The error amplifier 172 is used to amplify the error between the input reference level VREF and the level Vfb obtained by the feedback loop 178, ultimately achieving VREF = Vfb, thereby achieving high open-loop gain of the system.

[0080] The driver stage 174 is used to drive the output stage 176 of the voltage stabilization module 17. Since the output stage 176 is generally a relatively large device, a dedicated driver stage 174 is configured for driving it.

[0081] The output stage 176 is an output module of the voltage stabilization and transformation module 17 , and is configured to output a target voltage level V2 .

[0082] The feedback loop 178 is used to sample the output level V2 and feed the sampled signal back to the error amplifier 172, thereby achieving a closed-loop transmission coefficient K.

[0083] Figure 8 Shown Figure 4 A schematic diagram of another embodiment of a drive device 10 is shown.

[0084] In such Figure 8 In the illustrated embodiment, the inverting module 12 may include a first transistor 122' and a second transistor 124'. A first electrode of each of the first transistor 122' and the second transistor 124' is connected to the pulse voltage signal Vin, a third electrode of the first transistor 122' is connected to the third electrode of the second transistor 124' to output a first intermediate level signal Vy to the isolation capacitor 14, a second electrode of the first transistor 122' is connected to the adjustable voltage V2, and a second electrode of the second transistor 124' is grounded (GND).

[0085] The driving module 16 may include a third transistor 162', wherein the first electrode of the third transistor 162' receives the second intermediate level signal Vx from the isolation capacitor 14, the second electrode of the third transistor 162' is connected to the power supply voltage VDD1 of the driving module 16, and the third electrode of the third transistor 162' is connected to the light-emitting device 20 of the laser radar 1, for providing a driving current Id to the light-emitting device 20.

[0086] The input end of the isolation capacitor 14 is connected to the third electrode of the first transistor 122 ′ and the third electrode of the second transistor 124 ′ to receive the first intermediate level signal Vy. The output end of the isolation capacitor 14 outputs the second intermediate level signal Vx to the driving module 16 .

[0087] In such Figure 8 In the illustrated embodiment, the first transistor 122' may be a PNP transistor, the second transistor 124' may be an NPN transistor, and in the specification, the first electrode corresponds to the base (B), the second electrode corresponds to the emitter (E), and the third electrode corresponds to the collector (C).

[0088] In addition, the third transistor 162 ′ may be a PNP transistor, and in the specification, the first electrode is the base (B), the second electrode corresponds to the emitter (E), and the third electrode corresponds to the collector (C).

[0089] Here, PNP tube refers to PNP type transistor, which is a triode composed of two P-type semiconductors with one N-type semiconductor sandwiched in the middle. Similarly, NPN tube refers to NPN type transistor, which is a triode composed of two N-type semiconductors with one P-type semiconductor sandwiched in the middle.

[0090] exist Figure 6 In the embodiment shown, the third transistor 162 is described as a PMOS transistor of the same type as the first transistor 122. Figure 8In the embodiment shown, the third transistor 162' is described as a PNP transistor of the same type as the first transistor 122'. However, those skilled in the art will appreciate that the present invention is not limited thereto, and various transistors may be mixed and used. For example, in Figure 6 In the embodiment shown, the first transistor 122 can be implemented as a PMOS transistor, and the third transistor 162 can be implemented as a PNP transistor, or Figure 8 In the illustrated embodiment, the first transistor 122 ′ may be implemented as a PNP transistor, and the third transistor 162 ′ may be implemented as a PMOS transistor.

[0091] The above-mentioned scheme of the present invention simplifies the circuit structure of the driving device of the light-emitting device of the laser radar, reduces the various parasitic resistances, parasitic capacitances and other problems caused by the complexity of the circuit, and since the driving current can be adjusted without step-by-step accumulation, direct control of the driving current is achieved, making the adjustment speed faster and easily achieving nanosecond (ns) level control.

[0092] Those skilled in the art will appreciate that, depending on different application scenarios, the solutions according to the inventive concept of the present invention can be easily implemented as hardware circuits (such as FPGA or ASIC), driving methods or corresponding driver programs.

[0093] When the light-emitting device 20 of the laser radar is driven by the driving device 10 according to the present invention, if the light intensity of the echo received by the receiver of the laser radar (not shown in the figure) is too strong or too weak and cannot detect obstacles well, the controller of the laser radar (not shown in the figure) can automatically send a control signal to the driving device 10 according to the echo intensity to reduce or increase the driving current Id of the light-emitting device 20, thereby reducing or increasing the light intensity emitted by the light-emitting device 20.

[0094] In one embodiment, the driver 10 receives a control signal from the controller requesting an increase in the light intensity of the light-emitting device 20. Before the next pulse voltage signal Vin is input to the driver 10, the voltage stabilization and transformation module 17 increases the voltage value of the output adjustable level V2 (e.g., by increasing the reference level VREF of the adjustable voltage source 18) in accordance with the control signal. Since the high level of the first intermediate level signal Vy corresponds to the adjustable level V2, the high level of Vy also increases. Accordingly, the low level (VDD1-V2) of the second intermediate level signal Vx output by the isolation capacitor 14 decreases. According to formula (2), when Vx decreases, the on-resistance Rdson of the driver module 16 decreases, and the maximum value Imax of the drive current Id increases (as shown in formula (1) above).

[0095] In another example, the driver 10 receives a control signal from the controller requesting a reduction in the light intensity of the light-emitting device 20. Before the next pulse voltage signal Vin is input to the driver 10, the voltage stabilization and transformation module 17 reduces the output adjustable voltage level V2 (e.g., by reducing the reference voltage VREF of the adjustable voltage source 18) in accordance with the control signal, thereby reducing the high level (V2) of the first intermediate level signal Vy. At this point, due to the reduction in adjustable level V2, the low level (VDD1-V2) of the second intermediate level signal Vx output by the isolation capacitor 14 increases, and the on-resistance Rdson of the driver module 16 increases (as shown in formula (2) above), thereby reducing the maximum value Imax of the drive current Id (as shown in formula (1) above).

[0096] In this way, each time the light emitting device 20 of the laser radar emits light (for example, in combination with Figure 1 When the laser radar performs the next line scan of the vertical field of view in the horizontal field of view direction), the control signal is used to control the stable voltage transformation module 17 to stably adjust the level value of the output variable level, thereby stably adjusting the driving current Imax of the light-emitting device 20.

[0097] Various aspects of the embodiments of the present invention have been described above with reference to the accompanying drawings. It should be understood that the above description is merely exemplary, and the present invention is not limited to the specific implementations described above and shown in the accompanying drawings. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the embodiments described. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to the technology in the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A driving device for a laser radar light emitting device, wherein the laser radar light emitting device is a high-side driver, and the driving device comprises: an inverting module, the input end of which is connected to the pulse voltage signal (Vin) and an adjustable level (V2), and outputs a first intermediate level signal (Vy), wherein the first intermediate level signal (Vy) is inverted with respect to the pulse voltage signal (Vin); an isolation capacitor receiving the first intermediate level signal (Vy) and outputting a second intermediate level signal (Vx); as well as a driving module receiving the second intermediate level signal (Vx) and providing a driving current to the light emitting device to drive the light emitting device to emit light, wherein the driving current is adjusted according to the adjustable level (V2); A stabilizing transformer module is configured to receive an input of an adjustable voltage source and output the adjustable level (V2), so that when the adjustable voltage source is adjusted, the adjustable level is stably adjusted along with the adjustable voltage source, wherein the stabilizing transformer module includes a low dropout linear regulator (LDO).

2. The driving device according to claim 1 , wherein the inverting module comprises a first transistor and a second transistor, and wherein The first electrodes of the first transistor and the second transistor are both connected to the input pulse voltage signal (Vin), The second electrode of the first transistor is connected to the adjustable voltage level (V2), The third electrode of the first transistor is connected to the third electrode of the second transistor, and A second electrode of the second transistor is grounded.

3. The driving device according to claim 1 , wherein the driving module comprises a third transistor, and wherein The first electrode of the third transistor is connected to the second intermediate level signal (Vx), the second electrode of the third transistor is connected to the power supply voltage (VDD1) of the driving module, and the third electrode of the third transistor is connected to the light-emitting device of the laser radar to provide the driving current to the light-emitting device. 4 . The driving device according to claim 1 , wherein the first transistor is a PNP transistor or a PMOS transistor, and the second transistor is an NPN transistor or an NMOS transistor. The driving device according to claim 4 , wherein the third transistor is a PNP transistor or a PMOS transistor.

6. A driving device as described in claim 1, wherein the high potential of the pulse voltage signal is a first potential (VDD), the low potential is a second potential, and the high potential of the first intermediate level signal (Vy) output by the inverting module is determined by the adjustable level (V2), and the low potential is the second potential.

7. The driving device according to claim 1 , wherein an input terminal of the isolation capacitor is connected to the third electrode of the first transistor and the third electrode of the second transistor to receive the first intermediate level signal (Vy), and an output terminal of the isolation capacitor outputs the second intermediate level signal (Vx) to the driving module, wherein the second intermediate level signal (Vx) is in phase with the first intermediate level signal (Vy), and a high potential of the second intermediate level signal (Vx) is the power supply voltage (VDD1) of the driving module, and a low potential is the difference between the power supply voltage (VDD1) of the driving module and the adjustable level (V2).

8. The driving device according to claim 1, wherein the driving module further comprises a first resistor and at least one diode connected in parallel between the output terminal of the isolation capacitor and the power supply voltage (VDD1) of the driving module.

9. The driving device of claim 8, wherein the at least one diode comprises a first diode (166), and a cathode of the first diode is connected to a power supply voltage (VDD1) of the driving module, and an anode of the first diode is connected to the second intermediate level signal to limit the second intermediate level signal.

10. The driving device according to claim 8 or 9, wherein the at least one diode comprises a second diode (168), and an anode of the second diode is connected to the power supply voltage (VDD1) of the driving module, and a cathode of the second diode is connected to the second intermediate level signal for charging the second intermediate level signal when the third transistor is turned off.

11. The driving device according to claim 1, wherein the maximum value of the driving current is determined based on a power supply voltage (VDD1) of the driving module, inherent parameters of the third transistor, a parasitic resistance of the light emitting device, and the second intermediate level signal (Vx).

12. The driving device according to claim 11, wherein the second intermediate level signal (Vx) is determined by the power supply voltage (VDD1) of the driving module and the adjustable level (V2).

13. The driving device according to claim 1, wherein the pulse voltage signal is a short pulse signal.

14. A laser radar comprising: The drive device according to any one of claims 1 to 13; as well as The light-emitting device of the laser radar includes a parasitic resistance, a parasitic inductance and a light-emitting device connected in series to the third electrode of the third transistor, and the parasitic resistance and parasitic inductance connected in series are connected to the high-end side of the light-emitting device, and the low-end side of the light-emitting device is grounded.

15. The laser radar of claim 14, wherein the light emitting device comprises an edge emitting laser (EEL) or a vertical cavity surface emitting laser (VCSEL).

16. A method for driving a laser radar light emitting device, the method using the laser radar according to claim 14 or 15, the method comprising: An inverting module is used to receive an input pulse voltage signal (Vin) and an adjustable level (V2) and output a first intermediate level signal (Vy), wherein the first intermediate level signal (Vy) is inverted with respect to the pulse voltage signal (Vin); receiving the first intermediate level signal (Vy) by utilizing an isolation capacitor and outputting a second intermediate level signal (Vx) to a driving module; as well as The driving module is used to provide a driving current to the light emitting device to drive the light emitting device to emit light, The driving current is adjusted by adjusting the adjustable level (V2).

17. The method of claim 16, wherein the high potential of the pulse voltage signal is a first potential (VDD), the low potential is a second potential, and the high potential of the first intermediate level signal (Vy) output by the inverting module is determined by the adjustable level (V2), and the low potential is the second potential.

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