Circuit and control method for energy recovery, driving circuit, laser radar

Abstract

The present disclosure provides a circuit and a control method for energy recovery, a driving circuit and a laser radar. The circuit for energy recovery comprises: at least one power supply end configured to be connected with a first energy storage capacitor; a plurality of power supply rails, comprising: a first power supply rail configured to be connected with a first power supply; a second power supply rail configured to be connected with a ground wire; a third power supply rail configured to be connected with a second energy storage capacitor; and a switch circuit connected between the power supply end and the plurality of power supply rails, configured to turn on at least one of the power supply end and the plurality of power supply rails, or to turn off the path between the power supply end and the plurality of power supply rails.

Description

Technical Field

[0001] This disclosure relates to the field of laser control technology, and more particularly to circuits and control methods for energy recovery, drive circuits, and lidar. Background Technology

[0002] To achieve independent control of the lasers in a two-dimensional laser array, a bipolar addressing method can be used to drive the lasers. This requires separate control of the laser's anode and cathode. A relatively reliable and effective control scheme involves connecting an energy storage capacitor to the laser's anode and a switch with high current driving capability to the cathode. The switching on and off of the laser's anode is achieved by switching the voltage of the energy storage capacitor connected to the anode.

[0003] LiDAR achieves coverage of the upper field of view in a first direction (e.g., horizontal or vertical) by rotating the scanning mirror or illuminating lasers at different locations in batches. It also achieves coverage of the upper field of view in a second direction (e.g., perpendicular to the first direction) by rotating the scanning mirror or illuminating lasers at different locations in batches. To ensure the lasers can effectively capture moving targets, LiDAR needs a certain frame rate, meaning the time allotted for illuminating the laser at each scanning angle is limited. When using a two-dimensional laser array with a bipolar addressing drive scheme in LiDAR, the switching frequency of the anode and cathode of the laser array is high due to time constraints. This leads to significant energy waste in the energy storage capacitors connected to the lasers, resulting in increased power consumption of the LiDAR. Summary of the Invention

[0004] This disclosure provides a circuit and control method for energy recovery, a drive circuit, and a lidar.

[0005] This disclosure provides a circuit for energy recovery, comprising:

[0006] At least one power supply terminal is configured to be connected to the first energy storage capacitor;

[0007] Multiple power rails, including: a first power rail configured to be connected to a first power source; a second power rail configured to be connected to ground; and a third power rail configured to be connected to a second energy storage capacitor.

[0008] A switching circuit, connected between a power supply terminal and multiple power rails, is configured to either connect the power supply terminal to at least one of the multiple power rails or disconnect the power supply terminal from the multiple power rails.

[0009] Optionally, the circuit for energy recovery includes multiple power supply terminals;

[0010] A switching circuit, connected between multiple power supply terminals and multiple power rails, is configured to either connect at least one power supply terminal and at least one of the multiple power rails, or disconnect the connection between the multiple power supply terminals and the multiple power rails.

[0011] Optionally, the switching circuit includes: a first gating circuit configured to turn on at least one power supply terminal and one of a plurality of power rails.

[0012] Optionally, the first gating circuit includes at least one first gating unit. The first gating unit includes:

[0013] The first end is connected to at least one power supply end;

[0014] Multiple second terminals are connected to multiple power rails, and different second terminals are connected to different power rails;

[0015] The first gating unit is configured to either connect the first terminal and one of the plurality of second terminals, or disconnect the path between the first terminal and the plurality of second terminals.

[0016] Optionally, the first gating circuit includes multiple first gating units, with different first gating units connected to different power supply terminals.

[0017] Optionally, the first gating circuit further includes at least one second gating unit, which is connected between the first gating unit and a plurality of power supply terminals.

[0018] The second gating unit includes:

[0019] The third end connects to the first end;

[0020] Multiple fourth terminals, each connected to multiple power supply terminals, with different fourth terminals connected to different power supply terminals;

[0021] The second gating unit is configured to either connect the third terminal and one of the multiple fourth terminals, or disconnect the path between the third terminal and the multiple fourth terminals.

[0022] Optionally, the first strobe unit includes:

[0023] The first switching switch is connected between the power supply terminal and the first power rail;

[0024] The second switch is connected between the power supply end and the second power rail;

[0025] The third switching switch is connected between the power supply end and the third power rail.

[0026] Optionally, the first switching switch includes: a P-type metal-oxide-semiconductor field-effect transistor;

[0027] The second switching switch includes: an N-type metal-oxide-semiconductor field-effect transistor;

[0028] The third switching switch includes two N-type metal-oxide-semiconductor field-effect transistors connected in series.

[0029] Optionally, the first gating unit includes a multiplexer. The multiplexer includes:

[0030] Multiple input terminals, connected to multiple power rails, with different input terminals connected to different power rails;

[0031] The output terminal is connected to at least one power supply terminal;

[0032] The control terminal is configured to respond to control signals to either turn on the output terminal and one of the multiple input terminals, or to disconnect the path between the multiple input terminals and the output terminal.

[0033] Optionally, the first selection unit includes: a fourth switching switch. The fourth switching switch includes:

[0034] The stationary end is connected to at least one power supply end;

[0035] Multiple moving terminals are connected to multiple power rails, and different moving terminals are connected to different power rails;

[0036] The fourth switch is configured to either connect the stationary terminal and one of the multiple moving terminals, or disconnect the path between the stationary terminal and the multiple moving terminals.

[0037] Optionally, the second gating unit includes multiple transistor switches. The transistor switches are connected between the first terminal and the fourth terminal, and different transistor switches are connected to different fourth terminals.

[0038] Optionally, the second gating unit includes at least one of the following:

[0039] Multiplexer; or

[0040] Single-pole multi-throw switch.

[0041] Optionally, the energy recovery circuit includes at least one second energy storage capacitor, and the capacitance of the second energy storage capacitor is greater than the capacitance of the first energy storage capacitor.

[0042] This disclosure provides a circuit for driving a laser, including:

[0043] At least one first energy storage capacitor, the first end of which is used to connect to the laser;

[0044] In any of the foregoing embodiments, the power supply terminal of the energy recovery circuit is connected to the first terminal of the first energy storage capacitor.

[0045] Optionally, the circuit for driving the laser includes multiple first energy storage capacitors and multiple power supply terminals, with different first energy storage capacitors connected to different power supply terminals.

[0046] This disclosure provides a lidar, including:

[0047] At least one laser;

[0048] In any of the foregoing embodiments, the circuit for driving the laser is connected to the first end of the first energy storage capacitor.

[0049] Optionally, the lidar includes multiple lasers and multiple first energy storage capacitors; wherein,

[0050] Multiple lasers include at least one group of lasers, and each group of lasers includes at least one laser;

[0051] Different laser groups are connected to different first energy storage capacitors.

[0052] Optionally, the lidar also includes at least one second gating circuit. The second gating circuit includes:

[0053] The fifth terminal is connected to the ground wire;

[0054] Multiple sixth terminals are connected to the laser array, and different sixth terminals are connected to different lasers in the laser array;

[0055] The second gating circuit is configured to connect or disconnect the path between the fifth terminal and at least one sixth terminal.

[0056] Optionally, a sixth terminal can be connected to multiple laser groups.

[0057] Optionally, the lidar also includes a controller connected to circuitry for driving the laser, configured to output control signals to turn on a power supply terminal and one of a plurality of power rails in a predetermined order.

[0058] This disclosure provides a method for controlling energy recovery, used to control the energy recovery circuit of any of the foregoing embodiments. The method for controlling energy recovery includes:

[0059] The switching circuit receives the first control signal;

[0060] The switching circuit turns on the power supply terminal and one of the multiple power rails in a first predetermined order based on a first control signal.

[0061] Alternatively, methods for controlling energy recovery may also include:

[0062] The second control signal is received by the switching circuit;

[0063] The switching circuit turns on the power supply terminal and one of the multiple power rails in a second predetermined order based on the second control signal.

[0064] In the energy recovery circuit of this embodiment, by controlling the switching circuit connected between the power supply terminal and multiple power rails, the charge stored in the first energy storage capacitor connected to the power supply terminal can be fed to the second energy storage capacitor connected to the third power rail for power supply to the power supply terminal connected to the third power rail. Therefore, the energy loss of the power supply terminal can be reduced, and the power consumption of the lidar can be reduced. Attached Figure Description

[0065] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the description of the embodiments of this disclosure or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0066] Figure 1 A schematic diagram of a circuit for driving a laser is shown.

[0067] Figure 2 A schematic diagram of a circuit for energy recovery, consistent with some embodiments of this disclosure, is shown.

[0068] Figure 3 A schematic diagram of a circuit for energy recovery, consistent with some embodiments of this disclosure, is shown.

[0069] Figure 4 A schematic diagram showing the voltage waveform change at the power supply terminal of an energy recovery circuit is shown.

[0070] Figure 5 A schematic diagram of a circuit for energy recovery, consistent with some embodiments of this disclosure, is shown.

[0071] Figure 6 A schematic diagram of a circuit for energy recovery, consistent with some embodiments of this disclosure, is shown.

[0072] Figure 7 A schematic diagram of a circuit for energy recovery, consistent with some embodiments of this disclosure, is shown.

[0073] Figure 8 A schematic diagram of a circuit for energy recovery, consistent with some embodiments of this disclosure, is shown.

[0074] Figure 9A schematic diagram of a circuit for driving a laser is shown, consistent with some embodiments of this disclosure.

[0075] Figure 10 A schematic diagram of another circuit for driving a laser, consistent with some embodiments of this disclosure, is shown.

[0076] Figure 11 A schematic diagram of a lidar structure consistent with some embodiments of this disclosure is shown.

[0077] Figure 12 A schematic diagram of another lidar structure consistent with some embodiments of this disclosure is shown.

[0078] Figure 13 A flowchart of a method for controlling energy recovery, consistent with some embodiments of this disclosure, is shown. Detailed Implementation

[0079] LiDAR (Light Detection and Ranging) uses laser light as a medium for object detection and has found applications in many fields. For example, LiDAR can be used in autonomous driving, industrial manufacturing, drones, robot recognition, geographic mapping, and environmental monitoring. In these applications, LiDAR can be mounted on vehicles to provide them with sensing data (e.g., point cloud data), enabling the vehicles to perform one or more functions such as analysis, decision-making, or control. Vehicles include, but are not limited to, vehicles, manufacturing terminals, ships, aircraft (e.g., flying vehicles or drones), robots (e.g., industrial robots or home robots), or surveying equipment.

[0080] LiDAR can include, but is not limited to, mechanical, semi-solid-state, or solid-state lidar. Semi-solid-state lidar can include, but is not limited to, microelectromechanical system (MEMS) lidar, rotating mirror lidar, tilting mirror lidar, or prism lidar. Solid-state lidar can include, but is not limited to, optical phase array (OPA) lidar or flash lidar. When a vehicle is equipped with multiple lidar units, the types of lidar units can be the same or different.

[0081] By controlling the anode and cathode of the laser separately, independent control of the lasers in a two-dimensional laser array can be achieved. Figure 1 A schematic diagram of a circuit for driving a laser is shown. (Reference) Figure 1 The laser array 10 includes multiple lasers. Figure 1The example shown is a 4x4 laser array. The anode of the laser is connected to a storage capacitor C0, which is connected to a high-voltage switch S. pu Connected to the high-voltage power supply VIN, the energy storage capacitor C0 also passes through the low-voltage switch S. pd Connected to ground (GND). The laser cathode is driven by switch S. trig Connected to ground Vss. When the anode of a certain laser column is selected, the high-voltage switch S between the energy storage capacitor C0 connected to that column and the power supply VIN is activated. pu Close the low-voltage switch S between the energy storage capacitor C0 and the ground wire Vss. pd Disconnect the high-voltage switch S of the anode connection of other unselected lasers. pu Disconnect, low-voltage switch S pd Close. When the laser is lit, the drive switch S between the laser cathode and ground Vss is closed. trig Then, a pulsed current flows through the laser selected by the intersection of the anode and the closed cathode, emitting pulsed laser light. It is understood that the number of laser arrays is not limited to... Figure 1 The number shown can be the same or different for each row or column of lasers.

[0082] Continue to refer to Figure 1 To maintain consistent laser intensity, the energy storage capacitor C0 maintains a stable voltage during laser emission. Therefore, after laser emission, the energy storage capacitor C0 still stores a significant amount of energy. When the column containing the laser is deselected, the energy in the energy storage capacitor C0 connected to that laser needs to be channeled through the low-voltage switch S. pd Release. This prevents the deselected laser from emitting light unintended while other lasers in the same column are emitting light. Under the frame rate requirements of the lidar (e.g., 10Hz or 20Hz), the anode switch of the laser drive circuit (e.g., high-voltage switch S) pu and low-voltage switch S pd The switching frequency is relatively high. This will result in a significant waste of energy in the energy storage capacitor C0.

[0083] This disclosure provides a circuit for energy recovery. In some embodiments, multiple power rails can be provided at the power supply terminal, and a switching circuit connected between the power supply terminal and the multiple power rails can be controlled. In this way, the charge stored in a first energy storage capacitor connected to the power supply terminal can be fed to a second energy storage capacitor connected to a third power rail, which can then be used to power the power supply terminal connected to the third power rail. This reduces energy loss at the power supply terminal, thereby reducing the power consumption of the lidar.

[0084] The following detailed description is provided with reference to the accompanying drawings, through specific embodiments and in conjunction with some specific application scenarios.

[0085] Figure 2A schematic diagram of a circuit for energy recovery, consistent with some embodiments of this disclosure, is shown. (Reference) Figure 2 In some embodiments, the circuit 20 for energy recovery may include at least one power supply terminal V0, multiple power rails 22, and a switching circuit 24.

[0086] The power supply terminal V0 can be connected to the first energy storage capacitor C1.

[0087] Multiple power rails 22 may include: a first power rail V rail1 Second power rail V rail2 and the third power rail V rail3 Among them, the first power rail V rail1 It can be connected to the first power supply VDD; the second power rail V rail2 It can be connected to ground (GND); third power rail V rail3 It can be connected to the second energy storage capacitor C2.

[0088] The switching circuit 24 is connected between the power supply terminal V0 and the multiple power rails 22, and can connect the power supply terminal V0 and at least one of the multiple power rails 22, or disconnect the power supply terminal V0 and the multiple power rails 22.

[0089] In some embodiments, among the plurality of power rails 22, there may be one or more third power rails V rail3 .

[0090] In some embodiments, multiple third power rails V rail3 Each third power rail V rail3 Each of them can be connected to a corresponding second energy storage capacitor C2.

[0091] The following combination Figure 2 Briefly describe the working principle of circuit 20 used for energy recovery.

[0092] Taking the energy recovery circuit 20, which includes a power supply terminal V0, as an example, the switching circuit 24 can connect the power supply terminal V0 to at least one of the multiple power rails 22. When the switching circuit 24 connects the power supply terminal V0 to the first power rail V... rail1 At that time, due to the first power rail V rail1 Connected to the first power supply VDD, the first power rail V rail1 It can supply power to the first energy storage capacitor C1 connected to the power supply terminal V0. And to the third power rail V rail3 After the second energy storage capacitor C2 stores a certain amount of charge, the third power rail V... rail3 It can also be used as a power supply. When the switching circuit 24 is turned on, the power supply terminal V0 is connected to the third power rail V. rail3 At that time, the third power rail V rail3It can supply power to the first energy storage capacitor C1 connected to the power supply terminal V0.

[0093] If there is charge in the first energy storage capacitor C1, when the power supply terminal V0 of the switching circuit 24 is turned on, it connects to the third power rail V among the multiple power rails 22. rail3 At that time, the charge in the first energy storage capacitor C1 connected to the power supply terminal V0 can be fed to the third power rail V. rail3 The second energy storage capacitor C2 is connected. Meanwhile, the power supply terminal V0 is disconnected from the third power rail V by the switching circuit 24. rail3 After the circuit is established, the second energy storage capacitor C2 will store the charge fed by the first energy storage capacitor C1. If the switching circuit 24 then conducts the third power rail V... rail3 Through the connection to the power supply terminal V0 or other power supply terminals, the second energy storage capacitor C2 can release the stored charge. In this way, the second energy storage capacitor C2 can charge the first energy storage capacitor C1 connected to the power supply terminal. In this manner, some energy in the first energy storage capacitor C1 can be recovered for future charging of that first energy storage capacitor C1, or for charging other first energy storage capacitors C1. This reduces the energy discharged from the first energy storage capacitor C1 to ground GND, thus reducing power consumption.

[0094] In some embodiments, the circuit 20 for energy recovery may include at least one second energy storage capacitor C2. The capacitance of the second energy storage capacitor C2 is greater than the capacitance of the first energy storage capacitor C1. For example, the capacitance of the second energy storage capacitor C2 may be much greater than the capacitance of the first energy storage capacitor C1.

[0095] Figure 3 A schematic diagram of a circuit for energy recovery, consistent with some embodiments of this disclosure, is shown. (Reference) Figure 3 In some embodiments, the circuit 30 for energy recovery includes multiple power supply terminals, multiple power rails 32, and a switching circuit 34.

[0096] Figure 3 The example shows two power supply terminals, including a first power supply terminal V1 and a second power supply terminal V2. The first power supply terminal V1 can be connected to the first energy storage capacitor C11, and the second power supply terminal V2 can be connected to the first energy storage capacitor C21.

[0097] The multiple power rails 32 include: the first power rail V rail1 Second power rail V rail2 and the third power rail V rail3 First power rail V rail1 Connected to the first power supply VDD, and the second power rail V rail2 Connected to ground, third power rail V rail3 With the second energy storage capacitor C rail Connection. Through multiple switching, the third power rail Vrail Once stabilized, it can form a supply voltage of 50% VDD, such as... Figure 3 As shown.

[0098] In some embodiments, the capacitance values ​​of the first energy storage capacitor C11 and the first energy storage capacitor C21 are equal.

[0099] In some embodiments, the second energy storage capacitor C rail The capacitance value is greater than the capacitance values ​​of the first energy storage capacitors C11 and C21. For example, the second energy storage capacitor C... rail The capacitance value can be much larger than that of the first energy storage capacitors C11 and C21.

[0100] In some embodiments, the circuit 30 for energy recovery may include a second energy storage capacitor C. rail In other embodiments, the second energy storage capacitor C rail It can be installed outside the energy recovery circuit 30 and connected to the corresponding power rail in the energy recovery circuit 30, such as... Figure 3 As shown.

[0101] Continue to refer to Figure 3 The switching circuit 34 can be connected between multiple power supply terminals and multiple power rails 32. The switching circuit 34 can connect at least one power supply terminal and at least one power rail of the multiple power rails 32, or disconnect the connection between the multiple power supply terminals and the multiple power rails.

[0102] In some embodiments, the switching circuit may include a first gating circuit. The first gating circuit can connect at least one power supply terminal and one of a plurality of power rails. In some embodiments, the first gating circuit can connect one power supply terminal and one of a plurality of power rails. In other embodiments, the first gating circuit can connect multiple power supply terminals and at least one of a plurality of power rails. For example, through the first gating circuit, different power supply terminals can be connected to the same power rail among the plurality of power rails. As another example, through the first gating circuit, different power supply terminals can be connected to different power rails among the plurality of power rails. Yet another example, through the first gating circuit, some power supply terminals can be connected to the same power rail among the plurality of power rails, and some power supply terminals can be connected to different power rails among the plurality of power rails.

[0103] In some embodiments, the first gating circuit may include at least one first gating unit. The first gating unit may include a first terminal and a plurality of second terminals. The first terminal is connected to at least one power supply terminal. The plurality of second terminals are connected to a plurality of power rails, and different second terminals are connected to different power rails. The first gating unit may enable or disable the connection between the first terminal and one of the plurality of second terminals. In some embodiments, the first terminal may be directly connected to the power supply terminal. In other embodiments, the first terminal and the power supply terminal may be indirectly connected. For example, the first terminal may be connected to the power supply terminal through other devices or circuits. In some embodiments, the second terminal may be directly connected to the power rail. In other embodiments, the second terminal may be indirectly connected to the power rail through other devices or circuits.

[0104] In some embodiments, the switching circuit may include a plurality of first gating circuits, each of which may be connected to a different power supply terminal. For example, see reference... Figure 3 The switching circuit 34 includes a first gating circuit 341 and a first gating circuit 342, wherein the first gating circuit 341 is connected between the first power supply terminal V1 and the multiple power rails 32, and the first gating circuit 342 is connected between the second power supply terminal V2 and the multiple power rails 32.

[0105] The first gating circuit can sequentially turn on the power supply terminal and multiple power rails. For example, continue to refer to Figure 3 During the power-on process of the first power supply terminal V1, the first power supply terminal V1 and the second power rail V can be turned on first. rail2 Then connect the first power supply terminal V1 and the third power rail V. rail3 Then connect the first power supply terminal V1 and the first power rail V. rail1 During this process, the first energy storage capacitor C11 can be charged. Similarly, during the power-off process of the first power supply terminal V1, the first power supply terminal V1 and the first power rail V can be turned on first. rail1 Then connect the first power supply terminal V1 and the third power rail V. rail3 Then, the first power supply terminal V1 and the second power rail V are connected. rail2 During this process, the first energy storage capacitor C11 can be discharged. It should be noted that different first gating circuits can operate simultaneously or at different times.

[0106] Figure 3 A circuit for energy recovery with two power supply terminals and a third power rail is shown. Figure 4 A schematic diagram showing the voltage waveform change at the power supply terminal of an energy recovery circuit is shown. The following references... Figure 1 , Figure 3 and Figure 4 This explains the principle of energy recovery.

[0107] If the power supply is not connected to an energy recovery circuit, refer to... Figure 1 The circuit structure shown has a power supply terminal connected to the first energy storage capacitor and via a high-voltage switch S. pu Connected to power supply VDD. The power supply is also connected via a low-voltage switch S. pd Connect to ground (GND).

[0108] refer to Figure 1 Let's take the example where the voltage of power supply VIN is equal to the voltage of the first power rail VDD. During the charging process, the energy consumed by the energy storage capacitor C0 is E1 = VIN * Q1, where Q1 is the amount of charge required for the voltage of energy storage capacitor C0 to rise from 0 to VDD, and Q1 = VDD * C0. Therefore:

[0109] E1=VDD*Q1=VDD*VDD*C0=C0*VDD 2 .

[0110] During the discharge process, the charge of the energy storage capacitor C0 is completely discharged to the ground wire GND through the low-voltage switch. All the energy stored in the energy storage capacitor C0 is discharged to ground, dissipated as Joule heat in the low-voltage switch S. pd superior.

[0111] If an energy recovery circuit is used, refer to... Figure 3 and Figure 4 First, the power-on process of the first power supply terminal V1 is described, during which the first energy storage capacitor C11 is charged. The power-on process includes two sub-processes: the voltage of the first power supply terminal V1 rises from 0 to 50% VDD, and the voltage rises from 50% VDD to VDD.

[0112] In the first sub-process of the power-on process, the switching circuit 34 connects the first power supply terminal V1 with the third power rail V. rail3 Third power rail V rail3 The second energy storage capacitor C is connected rail It can store electric charge; the second energy storage capacitor C rail The voltage is 50% VDD. In the first sub-process of the power-on procedure, the first power supply terminal V1 draws voltage from the third power rail V, which is 50% VDD. rail3 Charge is absorbed. The voltage at the first power supply terminal V1 rises from 0 to 50% VDD. The first sub-process of the power-on process does not consume energy from the first power supply VDD.

[0113] In the second sub-process of the power-on process, the switching circuit 34 disconnects the first power supply terminal V1 from the third power rail V. rail3 The connection is established, and the first power supply terminal V1 is connected to the first power rail V. rail1 The connection. In the second sub-process of the power-on process, the first power supply terminal V1 connects to the first power rail V. rail1Charge is absorbed on the first power supply VDD. The voltage at the first power supply terminal V1 rises from 50% VDD to VDD. In the second sub-process of the power-on process, the energy consumed is E2 = VDD * Q2 = VDD * C11 * 0.5 * VDD = 0.5C11 * VDD 2 .

[0114] Next, the power-down process of the second power supply terminal V2 is described, during which the first energy storage capacitor C21 discharges. The power-down process includes two sub-processes: the voltage of the second power supply terminal V2 drops from VDD to 50% VDD, and then drops from 50% VDD to 0.

[0115] Continue to refer to Figure 3 and Figure 4 In the first sub-process of the power-down process, the switching circuit 34 disconnects the second power supply terminal V2 from the first power rail V. rail1 The path is established, and the second power supply terminal V2 is connected to the third power rail V. rail3 The voltage at the second power supply terminal V2 drops from VDD to 50% VDD. During the first sub-process of the power-down procedure, the first energy storage capacitor C21 connected to the second power supply terminal V2 releases charge to the third power rail V with a voltage of 50% VDD. rail3 The charge released by the first energy storage capacitor C21 is stored in the third power rail V. rail3 The second energy storage capacitor C is connected rail middle.

[0116] In the second sub-process of the power-down procedure, the switching circuit 34 disconnects the second power supply terminal V2 from the third power rail V. rail3 The path is established, and the second power supply terminal HV2 is connected to the second power rail V. rail2 The connection. In the second sub-process of the power-down process, the first energy storage capacitor C21 connected to the second power supply terminal V2 continues to supply power to the second power rail V. rail2 Energy is released, and the voltage at the second power supply terminal V2 drops from 50% VDD to 0. In the second sub-process of the power-down process, the energy released by the first energy storage capacitor C21 to ground is E3 = VDD * Q3 = VDD * C21 * 0.5 * VDD = 0.5C21 * VDD 2 .

[0117] In some embodiments, the third power rail at 50% VDD can be formed by continuously switching the conduction state with multiple power supply terminals. For example, during the power supply terminal switching process, the first power supply terminal V1 switches from the third power rail at 50% VDD. rail3 The amount of charge extracted is equal to the amount released from the second power supply terminal V2 to the third power rail V (50% of VDD). rail3 The amount of charge. This allows the third power rail at 50% VDD to maintain charge conservation, thus stabilizing the voltage of the third power rail. From the above and... Figure 4 According to the consistent energy recovery process, if the capacitance values ​​of the first energy storage capacitor C11 and the energy storage capacitor C0 are equal, then the energy E3 discharged to ground by the first energy storage capacitor C21 is 50% of the energy E1 discharged to ground by the energy storage capacitor C0. This can reduce the power consumption of the circuit.

[0118] Figure 5 A schematic diagram of a circuit for energy recovery, consistent with some embodiments of this disclosure, is shown. The circuit 50 for energy recovery includes: multiple power supply terminals V1 to V4, multiple power rails 52, and a switching circuit.

[0119] In some embodiments, the first power supply terminal V1 is connected to the first energy storage capacitor C1, the second power supply terminal V2 is connected to the first energy storage capacitor C2, the third power supply terminal V3 is connected to the first energy storage capacitor C3, and the fourth power supply terminal V4 is connected to the first energy storage capacitor C4. Specifically, the capacitance values ​​of the first energy storage capacitors C1 to C4 can be equal.

[0120] In some embodiments, the plurality of power rails 52 include a first power rail V rail1 Second power rail V rail2 and multiple third power rails V rail31 V rail32 and V rail33 First power rail V rail1 Connect to the first power supply VDD. The second power rail V... rail2 Connect to ground (GND). Third power rail V rail31 With the second energy storage capacitor C rail1 Connection. Third power rail V rail32 With the second energy storage capacitor C rail2 Connection. Third power rail V rail33 With the second energy storage capacitor C rail3 Connection. In specific implementation, the second energy storage capacitor C rail1 C rail2 and C rail3 The capacitance values ​​can be equal or unequal. Through multiple switching operations of the switching circuit, multiple third power rails V... rail31 V rail32 and V rail33 Once stabilized, it can generate supply voltages of 25% VDD, 50% VDD, and 75% VDD, such as... Figure 5 As shown.

[0121] In some embodiments, the second energy storage capacitor C rail1 C rail2 and C rail3 The capacitance value is greater than the capacitance values ​​of the first energy storage capacitors C1 to C4. For example, the second energy storage capacitor C rail1 C rail2 and Crail3 The capacitance value can be much larger than the capacitance values ​​of the first energy storage capacitors C1 to C4.

[0122] In some embodiments, the circuit 50 for energy recovery may include a second energy storage capacitor C. rail1 C rail2 and C rail3 In other embodiments, the second energy storage capacitor C rail1 C rail2 and C rail3 It can be installed outside the energy recovery circuit 50 and can be connected to the corresponding power rail in the energy recovery circuit 50, such as... Figure 5 As shown.

[0123] In some embodiments, each power supply terminal is connected to a first gating unit between itself and multiple power rails. (See reference) Figure 5 The switching circuit may include first selection units 541 to 544. First selection unit 541 is connected between the first power supply terminal V1 and multiple power rails 52. First selection unit 542 is connected between the first power supply terminal V2 and multiple power rails 52. First selection unit 543 is connected between the first power supply terminal V3 and multiple power rails 52. First selection unit 544 is connected between the first power supply terminal V4 and multiple power rails 52.

[0124] In some embodiments, the first gating unit may include multiple switching switches. For example, there is one switching switch connected between each power supply terminal and each power rail. (See reference...) Figure 5 The four power supply terminals are connected to the five power rails respectively, and there are a total of 4*5=20 switching switches, including switching switches S11~S15, S21~S25, S31~S35 and S41~S45.

[0125] Similar to the aforementioned embodiments, taking the first power supply terminal V1 as an example, during the power-on process, the first power supply terminal HV1 and the third power rail V are sequentially connected. rail31 Third power rail V rail32 Third power rail V rail33 and the first power rail V rail1 The voltage at the first power supply terminal HV1 undergoes voltage changes from 0 to 25% HVDD, 25% HVDD to 50% HVDD, 50% HVDD to 75% HVDD, and 75% HVDD to HVDD. Taking the second power supply terminal V2 as an example, during the power-down process, the second power supply terminal HV2 is sequentially connected to the third power rail V. rail33 Third power rail V rail32 Third power rail V rail31 Second power rail V rail2The voltage at the second power supply terminal HV2 undergoes voltage changes from HVDD to 75% HVDD, 75% HVDD to 50% HVDD, 50% HVDD to 25% HVDD, and 25% HVDD to 0. Figure 5 In the circuit 50 used for energy recovery, the five power rails have a four-segment switching capability between the second and first power rails. The power supply only switches from the third power rail V. rail31 Switch to the second power rail V rail2 During the voltage drop from 25% VDD to 0, energy is discharged to ground. Therefore, the efficiency of the energy recovery circuit 50 can reach 75%, and the energy loss at the power supply end is reduced to 25% of the original, greatly reducing the power consumption of the circuit.

[0126] More generally, assume the energy recovery circuit has N+1 power rails, including a first power rail and a second power rail connected to ground. There are N switching segments between the first and second power rails. Assuming the voltage of the first power supply is VDD, the power supply only consumes energy when the voltage rises from VDD*(N-1) / N to VDD, according to the voltage magnitude of the corresponding power rail. The energy consumed is E. N =VDD*C1*[1-(N-1) / N]*VDD=1 / N*C1*VDD 2 Where C1 represents the capacitance of the first energy storage capacitor connected to the power supply terminal, and the power saving efficiency is (N-1) / N.

[0127] Figure 5 In the energy recovery circuit shown, each power supply terminal and each power rail is controlled by an independent first gating unit, as described above. Switching between different power supply terminals and multiple power rails can be performed in parallel or in a time-sharing manner. For example, multiple power rails 52 can simultaneously supply power to the first power supply terminal V1 and the second power supply terminal V2. Alternatively, multiple power rails 52 can simultaneously recover energy from the first power supply terminal V1 and the second power supply terminal V2. Yet another example is that multiple power rails 52 can simultaneously supply power to the first power supply terminal V1 and recover energy from the second power supply terminal V2. Still another example is that multiple power rails 52 can supply power to the first power supply terminal V1 and the second power supply terminal V2 or recover energy at different times.

[0128] In other embodiments of this disclosure, the first gating circuit may include at least one second gating unit in addition to at least one first gating unit. The second gating unit may be connected between the first gating unit and multiple power supply terminals. Specifically, the second gating unit may include a third terminal and multiple fourth terminals. The third terminal may be connected to a first terminal of the first gating unit. The fourth terminals may be connected to multiple power supply terminals, with different fourth terminals connected to different power supply terminals. The second gating unit may either connect the third terminal to one of the multiple fourth terminals or disconnect the connection between the third terminal and the multiple fourth terminals.

[0129] Figure 6 A schematic diagram of a circuit for energy recovery, consistent with some embodiments of this disclosure, is shown. In some embodiments, reference is made to... Figure 6 The circuit 60 for energy recovery includes multiple power supply terminals V1 to V4, multiple power rails 62, and a switching circuit 64. The switching circuit 64 includes a first gating circuit 641. The first gating circuit 641 includes a first gating unit 6411 and a second gating unit 6412. The first gating unit 6411 is connected to the second gating unit 6412. For example, the first gating unit 6411 and the second gating unit 6412 can be connected via a bus 6413.

[0130] In some embodiments, the first gating unit may be implemented using a switching component. (See reference...) Figure 6 The first gating unit 6411 may include multiple switching switches S11 to S15. The second gating unit 6412 includes multiple switching switches S21 to S24. The first gating unit 6411 and the second gating unit 6412 cooperate to connect at least one power supply terminal to multiple power rails, or disconnect at least one power supply terminal from multiple power rails. This allows the charge of the first energy storage capacitor connected to the power supply terminal to be fed to the second energy storage capacitor connected to the power rail that is connected to the power supply terminal during power-off, and then used to supply power to the connected power supply terminal when that power rail is connected, thereby reducing power consumption.

[0131] In Figure 6 In the embodiment shown, consistent with the energy recovery circuit 60, the switching switches in the switching circuit connecting multiple power supply terminals to multiple power rails are shared, and different power supply terminals need to be connected to multiple power rails in a time-sharing manner. The first selection circuit 641 includes a total of 4 + 5 = 9 switching switches. Therefore, compared to Figure 5 The switching circuit shown can greatly reduce the number of switches, thereby saving circuit area.

[0132] Compared to Figure 5 The switch circuit shown, Figure 6The switching circuit shown requires a longer time to charge or discharge the four first energy storage capacitors C1 to C4. Taking the switching between two power supply terminals as an example, a comparison... Figure 5 and Figure 6 Under the same conditions, this refers to the time required for the first energy storage capacitor to charge or discharge. Switching time can be understood as the conduction time between the power supply terminal and each power rail. Assume the switching time for each power rail switch is 1 unit. For example... Figure 5 In the energy recovery circuit shown, the first gating unit 541 and the first gating unit 542 connected to the two power supply terminals can operate in parallel. The switching time for the first gating unit 541 and the first gating unit 542 to switch the power rail simultaneously is 1. Power supply terminals V1 and V2 switch the power rail 4 times during power-on or power-off, so the switching time is 4. (Reference) Figure 6 The energy recovery circuit shown has power supply terminals V1 and V2 switching power rails 4+4 times during power-on or power-off, so the switching time is 8 seconds.

[0133] The number of switches can characterize the circuit area, and the switching time can characterize the switching speed between multiple power supplies. (Comparison) Figure 5 The switch circuit shown and Figure 6 The performance of the switching circuit shown needs to take into account both speed and area. Therefore, based on the size requirements of the product (e.g., LiDAR) and the requirements for circuit timing performance, an appropriate number of first and second gating units can be set in the switching circuit.

[0134] The above comparison shows that when the number of power supply terminals or power rails is large, Figure 6 The circuit shown for energy recovery offers superior overall performance. It is particularly advantageous when the number of power supply terminals or power rails is small. Figure 5 The circuit shown for energy recovery offers superior overall performance. Therefore, in specific applications, a suitable switching circuit structure can be selected based on the specific application requirements.

[0135] In some embodiments, reference Figure 6 In the energy recovery circuit 60, during the power-off process at the power supply terminal, the charge in the first energy storage capacitor connected to the power supply terminal can be fed to other first energy storage capacitors by turning on other switching switches in the second selection unit 6412. For example, if the first power supply terminal V1 is to be powered off and the second power supply terminal V2 is to be powered on, switching switches S21 and S22 can be closed directly. In this way, the charge in the first energy storage capacitor C1 can be directly fed to the first energy storage capacitor C2 connected to the second power supply terminal V2 for storage, thus recovering energy and saving power consumption.

[0136] As mentioned above, Figure 6The circuit shown for energy recovery can effectively save the area of ​​the switching circuit, but the switching time increases. In order to save circuit area and reduce switching time, in some embodiments, multiple power supply terminals can be grouped. The first gating circuit in the switching circuit can include multiple first gating units and multiple second gating units, which correspond one-to-one and are respectively connected to multiple power rails through a bus.

[0137] Figure 7 A schematic diagram of a circuit for energy recovery, consistent with some embodiments of this disclosure, is shown. In some embodiments, reference is made to... Figure 7 The circuit 70 for energy recovery may include multiple power supply terminals V1 to V4, multiple power rails 72, and a switching circuit 74.

[0138] For example, multiple power supply terminals V1 to V4 are divided into two groups, including a first power supply terminal group and a second power supply terminal group. The first power supply terminal group includes a first power supply terminal V1 and a second power supply terminal V2. The second power supply terminal group includes a third power supply terminal V3 and a fourth power supply terminal V4.

[0139] It is understood that the above grouping numbers and groupings are merely illustrative examples and are not intended to limit the scope of protection of this disclosure. In other embodiments, the power supply terminal groups may also be grouped in other ways. For example, the first power supply terminal group may include a first power supply terminal V1 and a third power supply terminal V3. The second power supply terminal group includes a second power supply terminal V2 and a fourth power supply terminal V4. In some embodiments, the grouping method may be determined based on the power-on and power-off sequence of each power supply terminal. Furthermore, when there are more power supply terminals, multiple power supply terminals can be divided into more power supply terminal groups, thereby further reducing the switching time. It should be noted that the number of power supply terminals included in different power supply terminal groups may be the same or different.

[0140] Continue to refer to Figure 7 The switching circuit 74 includes a first gating circuit 741. The first gating circuit 741 includes first gating units 74111 and 7412, and second gating units 74121 and 74122. The first gating unit 74111 and the second gating unit 74121 are connected via a first bus 74131. The first gating unit 74112 and the second gating unit 74122 are connected via a second bus 74132. Thus, through the first gating unit 74111 and the second gating unit 74121, during the power-off process of the first power supply terminal V1 or the second power supply terminal V2, the charge stored in the first energy storage capacitor C1 or the first energy storage capacitor C2 can be fed to the second energy storage capacitor C1 connected to the multiple power rails 72. rail3 C rail2 and C rail1 During the power-on process at the first power supply terminal V1 or the second power supply terminal V2, energy is drawn from the second energy storage capacitor C. rail1C rail2 and C rail2 Energy is obtained from the first power supply terminal V3 or the fourth power supply terminal V4 to save energy loss. Similarly, through the first gating unit 74112 and the second gating unit 74122, during the power-down process of the third power supply terminal V3 or the fourth power supply terminal V4, the charge stored in the first energy storage capacitor C3 or the first energy storage capacitor C4 can be fed to the second energy storage capacitor C4 connected to the multiple power rails 72. rail3 C rail2 and C rail1 In the middle. During the power-on process at the third power supply terminal V3 or the fourth power supply terminal V4, energy is drawn from the second energy storage capacitor C. rail1 C rail2 and C rail2 To obtain energy from the source, thus saving energy consumption.

[0141] Power supplies in different power supply groups can be selected simultaneously, thus saving switching time. Figure 7 In a similar embodiment, the power supply terminals in the power supply terminal group connected to the first bus 74131 and the second bus 74132 can be turned on simultaneously. This is consistent with... Figure 6 The circuit shown can reduce switching time by half.

[0142] In some embodiments, during the power-off process at the power supply terminal, two switching switches in the second gating unit connected to the power supply terminal can be activated to feed the charge in the first energy storage capacitor connected to the power supply terminal to other power supply terminals in the same power supply terminal group. For example, refer to Figure 7 If the first power supply terminal V1 is powered off and the second power supply terminal V2 is powered on, the switching switches S211 and S212 in the second selection unit 74121 can be closed during the power-off process of the first power supply terminal V1 to feed the charge in the first energy storage capacitor C1 to the first energy storage capacitor C2.

[0143] The following detailed examples illustrate the specific implementation methods of the first and second gating units.

[0144] In some embodiments, the first gating unit may be implemented by a switching component.

[0145] refer to Figure 3 The first gating circuit 341 includes a first gating unit 3411. The first gating circuit 342 includes a first gating unit 3421. The first gating unit 3411 includes a first switching switch S11, a second switching switch S12, and a third switching switch S13. The first gating unit 3421 may include a first switching switch S21, a second switching switch S22, and a third switching switch S33.

[0146] The connection relationship between the switching switch and the power supply terminal and the power rail in the first gating unit is illustrated by the example of the switching switch in the first gating unit 3411. The first switching switch S11 can be connected to the first power supply terminal V1 and the first power rail V. rail1 Between. The second switching switch S12 can be connected to the first power supply terminal V1 and the second power rail V. rail2 Between. The third switching switch S13 can be connected to the first power supply terminal V1 and the third power rail V. rail3 between.

[0147] In some embodiments, the first switching switch may include a P-type metal-oxide-semiconductor field-effect transistor (MOSFET).

[0148] In some embodiments, the second switching switch may include an N-type MOSFET.

[0149] In some embodiments, the third switching switch may include two N-type MOSFETs connected in series.

[0150] In some embodiments, the first gating unit may include a multiplexer. The multiplexer may include multiple input terminals, an output terminal, and a control terminal. The multiple input terminals may be connected to multiple power rails, and different input terminals may be connected to different power rails. The output terminal may be connected to at least one power supply terminal. The control terminal may respond to a control signal to either connect the output terminal and one of the multiple input terminals, or disconnect the path between the multiple input terminals and the output terminal. Using a multiplexer in the first gating unit to connect or disconnect the power supply terminal from the power rail can save circuit area.

[0151] In some embodiments, the first gating unit may include a fourth switching switch. The fourth switching switch may include a stationary terminal and multiple moving terminals. The stationary terminal may be connected to at least one power supply terminal, and the multiple moving terminals may be connected to multiple power rails, with different moving terminals connected to different power rails. As can be seen, the fourth switching switch is a single-pole multi-throw switch. Using the fourth switching switch in the first gating unit to connect the power supply terminal to the power rail or disconnect the power supply terminal from the power rail can save circuit area.

[0152] In some embodiments, the second gating unit may include multiple transistor switches. The transistor switches may be connected between the first terminal and the fourth terminal, and different transistor switches may be connected to different fourth terminals. For example, the second gating unit may include multiple MOSFETs. Specifically, the second gating unit may include multiple N-type MOSFETs.

[0153] In some embodiments, the second gating unit may include a multiplexer. The multiplexer includes multiple input terminals, an output terminal, and a control terminal. The multiple input terminals can be connected to multiple power supply terminals, and different input terminals are connected to different power supply terminals. The output terminal can be connected to a first terminal of the first gating unit. The control terminal can, in response to a control signal, either connect the output terminal of the second gating unit and one of the multiple input terminals, or disconnect the path between the multiple input terminals and the output terminal of the second gating unit. The multiplexer in the second gating unit connects the power supply terminal to the first gating unit. The power supply terminal is connected to the power rail through the first and second gating units. Alternatively, the multiplexer in the second gating unit can disconnect the path between the power supply terminal and the first gating unit, thereby disconnecting the path between the power supply terminal and the power rail.

[0154] In some embodiments, the second gating unit may include a single-pole multi-throw (SPMD) switch. The SPMD switch may include a stationary terminal and multiple moving terminals. The stationary terminal may be connected to a first terminal of the first gating unit, and the multiple moving terminals may be connected to multiple power supply terminals, with different moving terminals connected to different power supply terminals. The second gating unit uses the SPMD switch to connect the power supply terminals to the first gating unit and, through the first gating unit, to connect to the power rail. Alternatively, the second gating unit may use the SPMD switch to disconnect the path between the power supply terminals and the first gating unit, thereby disconnecting the path between the power supply terminals and the power rail. Using a SPMD switch in the second gating unit can save circuit area.

[0155] Figure 8 A schematic diagram of a circuit for energy recovery, consistent with some embodiments of this disclosure, is shown. Figure 8 The circuit structure shown can be used as Figure 6 The diagram shows a specific implementation of a circuit for energy recovery. In some embodiments, reference is made to... Figure 8 The circuit 80 for energy recovery may include multiple power supply terminals V1 to V4, multiple power rails 82, and a switching circuit 84. The multiple power rails 82 include a first power rail V1. rail1 Second power rail V rail2 Third power rail V rail31 V rail32 and V rail33 Third power rail V rail31 With the second energy storage capacitor C rail1 Connection. Third power rail V rail32 With the second energy storage capacitor C rail2 Connection. Third power rail V rail33 With the second energy storage capacitor C rail3 Connection. The switching circuit 84 includes a first gating circuit 841. The first gating circuit 841 may include a first gating unit 8411 and a second gating unit 8412.

[0156] Continue to refer to Figure 8 Multiple power rails 82 and multiple power supply terminals V1 to V4 can exchange charge via an intermediate bus 8413. In some embodiments, due to the first power rail V... rail1 Connected to the first power supply VDD, the first power rail V rail1 The voltage is always higher than that of bus 8413. Therefore, bus 8413 is connected to the first power rail V. rail1 The first switching switch S11 can be implemented using a p-type lateral double-diffused metal-oxide-semiconductor field-effect transistor (PLDMOS). Using a PLDMOS for the first switching switch S11 is better suited for high-voltage applications. Since the bus voltage 8413 is always higher than the ground voltage GND, the bus 8413 and the second power rail V... rail2 The second switching switch S12 between them can be implemented by an n-type lateral double-diffused metal-oxide-semiconductor field-effect transistor (NLDMOS).

[0157] In some embodiments, the power supply terminal is connected to the third power rail V. rail31 V rail32 and V rail33 The third switching switches S13, S14, and S15 can be N-type devices. Compared to P-type devices, N-type devices have higher conductivity and smaller size. Therefore, using N-type devices saves circuit area. Specifically, the third switching switches S13, S14, and S15 can be NLDMOS. In some embodiments, the power supply terminal is connected to the third power rail V. rail31 V rail32 and V rail33 The third switching switches S13, S14 and S15 between them can be P-type devices.

[0158] In some embodiments, the third switching switches S13, S14, and S15 can be controlled by two NLDMOS transistors connected in series. This way, regardless of which of the source and drain voltages of the NLDMOS transistors is higher, the third switching switches S13, S14, and S15 can be controlled to turn off, giving the third switching switches a bidirectional disconnection characteristic. (Continue to refer to...) Figure 8Since the charging or discharging of the first energy storage capacitors C1, C2, C3, and C4 all need to be completed through bus 8413, the voltage of bus 8413 is constantly changing. For example, when the first energy storage capacitors C1, C2, C3, and C4 are charging, the voltage of bus 8413 is less than or equal to the voltage of the third power rail V. rail31 V rail32 V rail33 The voltage of the bus 8413 is greater than or equal to the voltage of the third power rail when the first energy storage capacitors C1, C2, C3, and C4 are discharging. rail31 V rail32 V rail33 The voltage. NLDMOS includes a parasitic diode. To ensure that the first energy storage capacitors C1, C2, C3, and C4 are charged or discharged, the third switching switches S13, S14, and S15 can be controlled to turn on or off, and the third power rail V rail31 V rail32 and V rail33 Two NLDMOS transistors connected in series are used as a third switching switch. The sources of the two series-connected NLDMOS transistors are interconnected, or their drains are interconnected. For example... Figure 8 The third switching switches S13, S14 and S15 in the middle.

[0159] The second gating unit 8412 may include a plurality of transistor switches S21 to S24. In some embodiments, the second gating unit 8412 may include a plurality of N-type MOSFETs. Figure 8 As shown, each power supply terminal includes an NLDMOS transistor connected to the bus 8413. For example, the source of the NLDMOS is connected to the power supply terminal, and the drain of the NLDMOS is connected to the bus 8413. Thus, when the power supply terminal discharges, the body diode of the NLDMOS in the second gating unit 8412 helps the power supply terminal release charge to the bus 8413. Alternatively, the drain of the NLDMOS is connected to the power supply terminal, and the source of the NLDMOS is connected to the bus 8413. Thus, when the power supply terminal is charging, the body diode of the NLDMOS in the second gating unit 8412 helps the bus 8413 release charge to the power supply terminal.

[0160] This disclosure also provides a circuit for driving a laser. In the circuit for driving the laser, a circuit for energy recovery can be included to recover the charge accumulated during the laser's operation.

[0161] Figure 9 A schematic diagram of a circuit for driving a laser, consistent with some embodiments of this disclosure, is shown. In some embodiments, reference is made to... Figure 9The circuit 90 for driving the laser may include at least one first energy storage capacitor C1 and a circuit 92 for energy recovery. A first terminal of the first energy storage capacitor C1 may be connected to the laser D0. The circuit 92 for energy recovery includes a power supply terminal V0, which may be connected to the first terminal of the first energy storage capacitor C1.

[0162] For a detailed implementation of circuit 92 for energy recovery, please refer to the aforementioned... Figures 2 to 8 Consistent implementation methods will not be described in detail here.

[0163] In some embodiments, the circuit for driving the laser may include a plurality of first energy storage capacitors and a plurality of power supply terminals, with different first energy storage capacitors connected to different power supply terminals.

[0164] Figure 10 A schematic diagram of another circuit for driving a laser, consistent with some embodiments of this disclosure, is shown. In some embodiments, reference is made to... Figure 10 The circuit 100 for driving the laser may include multiple first energy storage capacitors C1 to C4 and a circuit 102 for energy recovery. The energy recovery circuit 102 includes multiple power supply terminals V1 to V4. Different first energy storage capacitors are connected to different power supply terminals. For example, the first power supply terminal V1 is connected to the first energy storage capacitor C1. The second power supply terminal V2 is connected to the first energy storage capacitor C2, the third power supply terminal V3 is connected to the first energy storage capacitor C3, and the fourth power supply terminal V4 is connected to the first energy storage capacitor C4. Furthermore, the first power supply terminal V1 is used to connect to the first laser D1. The second power supply terminal V2 is used to connect to the second laser D2, the third power supply terminal V3 is used to connect to the third laser D3, and the fourth power supply terminal V4 is used to connect to the fourth laser D4. The implementation of the energy recovery circuit 102 can be found in [reference needed]. Figures 3 to 8 Consistent implementation examples.

[0165] This disclosure also provides some embodiments of lidar.

[0166] Figure 11 A schematic diagram of a lidar structure consistent with some embodiments of the present disclosure is shown. In some embodiments, reference is made to... Figure 11 The lidar 110 may include at least one laser D0 and circuitry 112 for driving the laser. A first terminal of the laser D0 is connected to a first terminal of a first energy storage capacitor C1. A second terminal of the laser D0 may be directly connected to ground (GND). Alternatively, the second terminal of the laser D0 may be connected to ground (GND) via other devices (e.g., switching devices).

[0167] In the lidar 110, the circuit 112 for driving the laser can drive at least one laser D0 to emit laser light. The laser light is reflected when it encounters an object. The laser light reflected back to the lidar 110 can be called an echo. By processing the echo, the lidar 110 can sense environmental information such as the distance to the object and its reflectivity.

[0168] In some embodiments, the circuit 112 for driving the laser can be adopted with Figure 9 or Figure 10 A consistent circuit for driving the laser may include a circuit 1122 for energy recovery. The energy recovery circuit 1122 can recover the charge stored in the first energy storage capacitor C1 during the power-down process of the laser D0, and use it to power the laser D0 during the subsequent lighting process, thereby reducing the power consumption of the lidar 110.

[0169] Circuit 1122 for energy recovery can be referenced in... Figures 2 to 8 A consistent embodiment of the circuitry for energy recovery. For example, the circuitry 1122 for energy recovery may include at least one power supply terminal V0, multiple power rails, and switching circuitry. In some embodiments, the lidar 110 may also include a controller 114. The controller 114 may be connected to the circuitry and configured to output control signals to turn on at least one power supply terminal V0 and one of the multiple power rails in a predetermined sequence.

[0170] In some embodiments, the controller 114 can output a control signal to a switching circuit. By turning the switching circuit on or off, at least one power supply terminal V0 and one of the power rails can be turned on in a predetermined order. For example, the controller 114 can output a first control signal, and the switching circuit can turn on the power supply terminal V0 and one of the power rails in a first predetermined order based on the first control signal. Alternatively, the controller can output a second control signal, and the switching circuit can turn on the power supply terminal V0 and one of the power rails in a second predetermined order based on the second control signal.

[0171] refer to Figure 3 and Figure 11In some embodiments, the controller 114 may output a first control signal during the power-on process of the laser D0, and the switching circuit may conduct the power supply terminal V0 and one of the power rails in a first predetermined order based on the first control signal, so that the voltage of the power supply terminal V0 gradually increases. The controller 114 may output a second control signal during the power-off process of the laser D0, and the switching circuit may conduct the power supply terminal V0 and one of the power rails in a second predetermined order based on the second control signal, so that the voltage of the power supply terminal V0 gradually decreases. During the voltage drop of the power supply terminal V0, a ​​portion of the charge in the first energy storage capacitor C1 connected to the power supply terminal V0 may be fed to the second energy storage capacitor connected to the power rail in the energy recovery circuit. During the subsequent lighting process of the laser D0, the charge stored in the second energy storage capacitor may be re-provided to the power supply terminal to power the laser D0.

[0172] The controller 114 may be a circuit or device capable of generating control signals. In some embodiments, the controller 114 may include a circuit or device capable of generating instructions. For example, the controller 114 may include one or more combinations of a central processing unit (CPU), a microcontroller unit (MCU), a microprocessor unit (MPU), and a digital signal processor (DSP). Alternatively, the controller 114 may be a hardware circuit implemented using, but not limited to, an application-specific integrated circuit (ASIC) or a programmable logic device (PLD). Specifically, the hardware circuit implemented using a PLD may include, for example, a field-programmable gate array (FPGA).

[0173] When the controller 114 includes multiple devices or a combination of multiple devices, these devices can be set separately, partially integrated together, or fully integrated together. For example, the controller 114 can be implemented as a system on chip (SOC) or an ASIC.

[0174] In some embodiments, a lidar may include a plurality of lasers and a plurality of first energy storage capacitors; wherein the plurality of lasers may include at least one laser group, and each laser group includes at least one laser. Different laser groups may be connected to different first energy storage capacitors.

[0175] Figure 12A schematic diagram of another lidar system consistent with some embodiments of this disclosure is shown. In some embodiments, reference is made to... Figure 12 The lidar 120 may include a laser array 126 formed by multiple lasers and circuitry 122 for driving the lasers.

[0176] like Figure 12 As shown, multiple lasers form a 4x4 laser array 126. The laser array 126 includes multiple laser groups. Figure 12 Each laser group includes an example of a column of lasers, including laser groups Dr1 to Dr4. It is understood that each laser group may include one or more lasers, and multiple lasers may be arranged in other ways. This disclosure does not limit the specific arrangement of the lasers, nor does it limit the number or connection method of the lasers in each laser group. The first end of the laser may be connected to a power supply terminal in the circuit 122 used to drive the laser. In some embodiments, the second end of the laser may be directly connected to ground (GND). In other embodiments, the second end of the laser may be connected to ground (GND) through other devices or circuits.

[0177] In some embodiments, the laser may include a semiconductor laser, a fiber laser, or other types of lasers. For example, a semiconductor laser includes a laser emitting circuit, a vertical cavity surface emitting laser (VCSEL), an edge emitting laser (EEL), a distributed feedback laser (DFB), or similar devices. The above are merely examples, and the embodiments disclosed herein do not limit the type of laser.

[0178] The circuit 122 for driving the laser includes multiple first energy storage capacitors C1 to C4 and an energy recovery circuit 1222. The first energy storage capacitors C1 to C4 are respectively connected to corresponding power supply terminals in the energy recovery circuit 1222. Different first energy storage capacitors are connected to different power supply terminals. For example, referring to... Figure 12 The first laser group Dr1 is connected to the first energy storage capacitor C1. The second laser group Dr2 is connected to the first energy storage capacitor C2. The third laser group Dr3 is connected to the first energy storage capacitor C3. The first laser group Dr4 is connected to the first energy storage capacitor C4.

[0179] The circuit 122 for driving the laser may include multiple power supply terminals, multiple power rails, and a switching circuit connected between the multiple power supply terminals and the multiple power rails. For a specific implementation of the circuit 122 for driving the laser, please refer to the foregoing... Figure 9 or Figure 10 An embodiment of a circuit for driving a laser, consistent with the above. For a detailed implementation and principle of the circuit 1222 for energy recovery, please refer to [reference needed]. Figures 2 to 8 An embodiment of a consistent circuit for energy recovery.

[0180] During the laser's power-off process, the charge in the first energy storage capacitor connected to the laser can be stored in the second energy storage capacitor in the energy recovery circuit. During the laser's power-on process, the charge stored in the second energy storage capacitor can be released, driving the laser to emit light.

[0181] The circuit 122 for driving the laser includes a circuit 1222 for energy recovery. The circuit for driving the laser can recover a portion of the charge stored in the first energy storage capacitors C1 to C4 connected to the first terminals of the lasers in the laser array during the driving of one or more lasers in the laser array, thereby reducing power consumption.

[0182] In some embodiments, the controller 124 may output a control signal, and the switching circuit in the energy recovery circuit 1222 may turn on the corresponding power supply terminal based on the control signal to supply power to the connected laser and light up the laser.

[0183] For example, controller 124 can output a first control signal and a second control signal. A switching circuit can, based on the first control signal, turn on a corresponding power supply terminal and one of the multiple power rails in a first predetermined order. A switching circuit can, based on the second control signal, turn on a corresponding power supply terminal and one of the multiple power rails in a second predetermined order.

[0184] In some embodiments, the first control signal represents controlling the corresponding power supply terminal to power on, which can be achieved by connecting the corresponding power supply terminal and one of the multiple power rails in a voltage gradient order. Correspondingly, the second control signal represents controlling the corresponding power supply terminal to power off, which can be achieved by connecting the corresponding power supply terminal and one of the multiple power rails in a voltage gradient order. By exchanging charge between the first energy storage capacitors C1 to C4 and the second energy storage capacitor during the power supply terminal power-on or power-off process, the waste of charge in the first energy storage capacitor during the power-off process can be reduced, thereby reducing the power consumption of the lidar.

[0185] In some embodiments, the lidar 120 may further include at least one second gating circuit. (Continue to refer to...) Figure 12 The second gating circuit 128 may include a fifth terminal and multiple sixth terminals. The fifth terminal is connected to ground. The multiple sixth terminals can be connected to a laser array, and different sixth terminals are connected to different lasers in the laser array. The second gating circuit can connect or disconnect the path between the fifth terminal and at least one sixth terminal.

[0186] In some embodiments, reference Figure 12 A sixth terminal of the second gating circuit 128 can be connected to multiple laser groups. In this way, the second gating circuit 128, in conjunction with the circuit 122 for driving the lasers, can illuminate one or more lasers at a time.

[0187] In some embodiments, the second gating circuit 128 may include one or more switching switches. For example, the first terminal of each switching switch may be connected to ground, and the second terminal of each switching switch may be connected to the second terminal of each row laser, respectively. Figure 12 As shown.

[0188] In some embodiments, the second gating circuit may include one or more multiplexers. A multiplexer may include multiple input terminals, an output terminal, and a control terminal. The multiple input terminals may be connected to a second end of the laser; for example, different input terminals may be connected to different lasers in the same laser group. The output terminal may be connected to ground. The control terminal may, in response to a third control signal, either enable the output terminal of the multiplexer and one of the multiple input terminals, or disable the path between the multiple input terminals and the output terminal of the multiplexer.

[0189] In some embodiments, the second gating circuit may include one or more single-pole multi-throw (SPMD) switches. Each SPMD switch may include a stationary terminal and multiple moving terminals. The stationary terminal may be connected to ground, and the multiple moving terminals may be connected to multiple lasers. For example, as... Figure 12 As shown, multiple moving terminals are connected to different lasers in the same laser group. Alternatively, multiple moving terminals can be connected to lasers in different laser groups. The second gating circuit 128 uses a single-pole multi-throw switch to connect the laser to ground. This, combined with the circuit for driving the laser, connects to the power rail via a switching circuit, allowing the cross-selected laser to emit light. Using a single-pole multi-throw switch in the second gating circuit saves circuit space.

[0190] In some embodiments, the second gating circuit may include a plurality of transistor switches. The transistor switches may be connected between ground and a second terminal of the laser, and the control terminal of the transistor switches may, in response to a third control signal, select the second terminal of the laser connected to ground. For example, the second gating circuit may include a plurality of MOSFETs (e.g., N-type MOSFETs or P-type MOSFETs).

[0191] In some embodiments, such as Figure 12As shown, controller 124 can output a third control signal. In specific implementations, controller 124 can set the output timing of the first, second, and third control signals according to the required scan frame rate. Circuit 122 for driving the laser is connected to or disconnected from the first end of the laser in laser array 126 based on the first or second control signal. Second gating circuit 128 is connected to the second end of the laser based on the third control signal. The second gating circuit 128 and circuit 122 for driving the laser cooperate to enable the lasers in laser array 126 to emit light sequentially, achieving environmental perception.

[0192] The specific implementation of controller 124 can be found in controller 114 in the foregoing embodiments, and will not be described in detail here.

[0193] This disclosure also provides embodiments of methods for controlling energy recovery, which can be used to control and... Figures 2 to 12 The circuitry shown is consistent with embodiments of this disclosure for energy recovery. These methods for controlling energy recovery can reduce circuit power consumption.

[0194] Figure 13 A flowchart of a method for controlling energy recovery, consistent with some embodiments of this disclosure, is shown. In some embodiments of this disclosure, the method for controlling energy recovery may include steps 132 and 134.

[0195] Step 132: The first control signal is received by the switching circuit.

[0196] Step 134: The switching circuit turns on the power supply terminal and one of the multiple power rails in a first predetermined order based on the first control signal.

[0197] In some embodiments, continue to refer to Figure 13 The method for controlling energy recovery may include steps 136 and 138.

[0198] Step 136: The second control signal is received by the switching circuit.

[0199] Step 138: The switching circuit turns on the power supply terminal and one of the multiple power rails in a second predetermined order based on the second control signal.

[0200] In practical applications, this disclosure does not limit the order of steps 132 and 134 with steps 136 and 138.

[0201] In some embodiments, the method for controlling energy recovery can be used in scenarios where a laser is driven to emit light.

[0202] In some embodiments, the first control signal or the second control signal may be generated by a control circuit or controller in the energy recovery circuit, or may be output by a control circuit or controller outside the energy recovery circuit.

[0203] For example, the controller in the lidar can output control signals to control the energy recovery process. For instance, the controller can output a first control signal during laser power-on, and the switching circuit can, based on the first control signal, conduct the power supply terminal and one of the multiple power rails in a first predetermined sequence to cause the voltage at the power supply terminal to increase in a stepwise manner. The controller can output a second control signal during laser power-off, and the switching circuit can, based on the second control signal, conduct the power supply terminal and one of the multiple power rails in a second predetermined sequence to cause the voltage at the power supply terminal to decrease in a stepwise manner. During the voltage drop at the power supply terminal, the charge in the first energy storage capacitor connected to the power supply terminal can be fed to a second energy storage capacitor connected to the power rail in the energy recovery circuit. During subsequent laser illumination, the charge stored in the second energy storage capacitor can be re-provided to the power supply terminal to power the laser.

[0204] In this disclosure, the term "or" describes the relationship between related objects and indicates a non-exclusive inclusion. For example, "A or B" can include: only "A" exists, only "B" exists, and both "A" and "B" exist simultaneously, where "A" and "B" can be singular or plural. As another example, "A, B, or C" can include: only "A" exists, only "B" exists, only "C" exists, both "A" and "B" exist simultaneously, both "A" and "C" exist simultaneously, both "B" and "C" exist simultaneously, and both "A", "B", and "C" exist simultaneously, where "A", "B", and "C" can be singular or plural. Furthermore, the symbol " / " in this disclosure indicates an "or" relationship between the related objects before and after the symbol. In this disclosure, the term "at least one A or B" has the same meaning as "A or B" as described above. The term "at least one A, B, or C" has the same meaning as "A, B, or C" as described above.

[0205] It is understood that the devices in different embodiments of this disclosure that use the same markings or the same names are only used to characterize their relative positions and functions in the circuit, and do not limit their specific models or parameters. The required device models or parameters can be used according to actual needs, and are not intended to limit the relationship between the various embodiments.

[0206] In this disclosure, unless otherwise expressly specified and limited, ordinal numbers, such as “first,” “second,” etc., are used only to distinguish and describe related objects, and should not be construed as indicating or implying the relative importance or order between related objects. Furthermore, ordinal numbers do not represent the quantity of related objects. For example, “multiple” includes two or more, and other quantifiers are similar.

[0207] The above embodiments illustrate some circuits for energy recovery, circuits for driving lasers, lidar, and methods for controlling energy recovery. It should be noted that any method may include more or fewer steps, and the order of the steps may be the same or different. Embodiments of different methods or circuits can be referenced interchangeably, and embodiments of different methods or circuits can be combined for implementation.

[0208] While the embodiments disclosed above are provided, the present invention is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A circuit for energy recovery, comprising: At least one power supply terminal is configured to be connected to the first energy storage capacitor; Multiple power rails, including: a first power rail configured to be connected to a first power source; a second power rail configured to be connected to ground; and a third power rail configured to be connected to a second energy storage capacitor. A switching circuit, connected between the power supply terminal and the plurality of power rails, is configured to either connect the power supply terminal and at least one of the plurality of power rails, or disconnect the power supply terminal from the plurality of power rails.

2. The circuit according to claim 1, characterized in that, The circuit includes multiple power supply terminals; The switching circuit, connected between the plurality of power supply terminals and the plurality of power rails, is configured to either connect at least one of the power supply terminals and at least one of the plurality of power rails, or disconnect the path between the plurality of power supply terminals and the plurality of power rails.

3. The circuit according to claim 1 or claim 2, characterized in that, The switching circuit includes: The first gating circuit is configured to turn on at least one of the power supply terminals and one of the plurality of power rails.

4. The circuit according to claim 3, characterized in that, The first gating circuit includes at least one first gating unit; The first gating unit includes: The first end is connected to at least one of the power supply ends; Multiple second terminals are connected to the multiple power rails, and different second terminals are connected to different power rails; The first gating unit is configured to either connect the first terminal and one of the plurality of second terminals, or disconnect the path between the first terminal and the plurality of second terminals.

5. The circuit according to claim 4, characterized in that, The first gating circuit includes multiple first gating units, and different first gating units are connected to different power supply terminals.

6. The circuit according to claim 4, characterized in that, The first gating circuit further includes at least one second gating unit, the second gating unit being connected between the first gating unit and the plurality of power supply terminals; The second gating unit includes: The third end is connected to the first end; Multiple fourth terminals, each fourth terminal being connected to multiple power supply terminals, and different fourth terminals being connected to different power supply terminals; The second gating unit is configured to either connect the third terminal and one of the plurality of fourth terminals, or disconnect the path between the third terminal and the plurality of fourth terminals.

7. The circuit according to any one of claims 4 to 6, characterized in that, The first gating unit includes: A first switching switch is connected between the power supply terminal and the first power rail; The second switching switch is connected between the power supply terminal and the second power rail; The third switching switch is connected between the power supply terminal and the third power rail.

8. The circuit according to claim 7, characterized in that, The first switching switch includes: a P-type metal-oxide-semiconductor field-effect transistor; The second switching switch includes: an N-type metal-oxide-semiconductor field-effect transistor; The third switching switch includes two N-type metal-oxide-semiconductor field-effect transistors connected in series.

9. The circuit according to any one of claims 4 to 6, characterized in that, The first gating unit includes: a multiplexer; the multiplexer includes: Multiple input terminals are connected to the multiple power rails, and different input terminals are connected to different power rails; The output terminal is connected to at least one of the power supply terminals; The control terminal is configured to respond to a control signal to turn on the output terminal and one of the plurality of input terminals, or to disconnect the path between the plurality of input terminals and the output terminal.

10. The circuit according to any one of claims 4 to 6, characterized in that, The first selection unit includes: a fourth switching switch; the fourth switching switch includes: The stationary end is connected to at least one of the power supply ends; Multiple moving terminals are connected to the multiple power rails, and different moving terminals are connected to different power rails; The fourth switch is configured to either connect the stationary terminal and one of the plurality of moving terminals, or disconnect the path between the stationary terminal and the plurality of moving terminals.

11. The circuit according to claim 6, characterized in that, The second gating unit includes multiple transistor switches; The transistor switch is connected between the first terminal and the fourth terminal, and different transistor switches are connected to different fourth terminals.

12. The circuit according to claim 6, characterized in that, The second gating unit includes at least one of the following: Multiplexer; or Single-pole multi-throw switch.

13. The circuit according to claim 1, characterized in that, The energy recovery circuit includes at least one second energy storage capacitor, and the capacitance of the second energy storage capacitor is greater than the capacitance of the first energy storage capacitor.

14. A circuit for driving a laser, comprising: At least one first energy storage capacitor, the first end of which is used to connect to a laser; The circuit for energy recovery as described in any one of claims 1 to 13, wherein the power supply terminal of the circuit for energy recovery is connected to the first terminal of the first energy storage capacitor.

15. The circuit according to claim 14, characterized in that, The circuit includes multiple first energy storage capacitors and multiple power supply terminals, with different first energy storage capacitors connected to different power supply terminals.

16. A lidar, comprising: At least one laser; In the circuit of claim 14 or claim 15, the laser is connected to a first terminal of the first energy storage capacitor.

17. The lidar according to claim 16, characterized in that, The lidar includes multiple lasers and multiple first energy storage capacitors; wherein... The plurality of lasers includes at least one group of lasers, and each group of lasers includes at least one of the lasers; Different laser groups are connected to different first energy storage capacitors.

18. The lidar according to claim 17, characterized in that, It also includes at least one second gating circuit; the second gating circuit includes: The fifth terminal is connected to the ground wire; Multiple sixth terminals are connected to the laser group, and different sixth terminals are connected to different lasers in the laser group; The second gating circuit is configured to turn the fifth terminal on or off with at least one of the above-mentioned terminals. The pathway at the sixth end.

19. The lidar according to claim 18, characterized in that, One of the sixth terminals is connected to multiple laser groups.

20. The lidar according to claim 16, characterized in that, Also includes: A controller, connected to the circuit, is configured to output control signals to turn on the power supply terminal and one of the plurality of power rails in a predetermined order.

21. A method for controlling energy recovery, used to control the circuit for energy recovery as described in any one of claims 1 to 13, the method comprising: The switching circuit receives a first control signal; The switching circuit turns on the power supply terminal and one of the plurality of power rails in a first predetermined order based on the first control signal.

22. The method of claim 21, further comprising: The second control signal is received by the switching circuit; The switching circuit turns on the power supply terminal and one of the plurality of power rails in a second predetermined order based on the second control signal.

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