Laser radar driving chip, laser driver chip and laser radar

Abstract

The application discloses a driving chip for a laser radar, a laser driver chip and a laser radar. The driving chip for the laser radar according to an embodiment of the application comprises a shift register, a plurality of level converters, a plurality of drivers and a plurality of power switch tubes, the shift register outputs a control signal to one or more of the plurality of level converters based on a received signal, the level converter amplifies the received control signal so that an amplified signal output has a higher voltage, and the driver turns on the power switch tube based on the received amplified signal.

Description

Technical Field

[0001] This invention relates to lidar, and more particularly to a driving chip for lidar. Background Technology

[0002] In the field of autonomous driving, self-driving vehicles can use devices such as LiDAR (Light Detection and Ranging) to detect surrounding objects. LiDAR emits a laser beam into the surrounding three-dimensional space as a detection signal. After the laser beam illuminates an object in the surrounding space, it is reflected as an echo signal and returns. LiDAR compares the received echo signal with the emitted detection signal to obtain relevant information about the surrounding objects, such as distance and speed.

[0003] To emit a laser beam as described above, a lidar system requires a driving circuit to drive the laser source. Currently, commonly used narrow-pulse driving circuits for laser sources employ the principle of energy compression. (Refer to...) Figure 1 The circuit works as follows: The pulse switch signal controls the switching device to turn off and on. When the pulse switch signal is off, the switching device is off, and the external power supply charges the energy storage capacitor. The voltage across the energy storage capacitor then rises. After charging is complete, the voltage across the energy storage capacitor is equal to the voltage of the external power supply. The energy storage capacitor stores electrical energy in the form of charge. When the pulse switch signal is on, the driver instantly increases the driving capability of the pulse switch signal and quickly turns on the switching device. The energy storage capacitor discharges instantaneously through the circuit formed with the laser, generating a narrow pulse current that acts on the laser, and the laser emits a narrow pulse laser.

[0004] In the prior art, the driver and the switching device are composed of two discrete components. The driver is responsible for converting the pulse signal into a high-voltage, high-current drive signal, and the switching device is responsible for controlling the laser to turn on and off.

[0005] Because the existing technology separates the driver and switching devices, firstly, parasitic inductance and capacitance will be generated between the two discrete devices, which will affect the narrow pulse control capability of the laser; secondly, building a driving system with discrete devices requires a large number of discrete devices in the design of multi-channel lasers such as 32-channel lasers, resulting in a large size and capacity of the driving system.

[0006] Therefore, there is a need to provide a driving circuit that can solve the above problems. Summary of the Invention

[0007] This invention provides a driver chip for lidar that facilitates miniaturization, and a lidar having the same chip.

[0008] According to an embodiment of the present invention, a driver chip for a lidar includes a shift register, a plurality of level converters, a plurality of drivers, and a plurality of power switches. The shift register outputs a control signal to one or more of the plurality of level converters based on a received signal. The level converters amplify the received control signal to make the output amplified signal have a higher voltage. The drivers turn on the power switches based on the received amplified signal.

[0009] Furthermore, it may also include: a latch located between the level converter and the driver, which receives an amplified signal from the level converter and outputs it to the driver.

[0010] Furthermore, the shift register can be supplied with a first voltage, the level shifter, latch, and driver can be supplied with a second voltage, and the power switch can be supplied with a third voltage, the voltage value of the third voltage being greater than or equal to the voltage value of the second voltage, and the voltage value of the second voltage being greater than the voltage value of the first voltage.

[0011] Furthermore, the power switch transistor can be strip-shaped, and multiple power switch transistors are arranged along the width direction of the strip.

[0012] Furthermore, the signals received by the shift register may include a shift clock signal, a serial data input signal, a reset control signal, and a latch clock signal.

[0013] Furthermore, the shift register may have a port for serially outputting overflowing data.

[0014] Furthermore, the shift register can output a temperature detection feedback signal when the detected temperature exceeds a predetermined temperature.

[0015] Furthermore, the power switch may include a MOS structure, and the shift register may include a CMOS structure.

[0016] A lidar according to another embodiment of the present invention includes: a lidar driver chip as described above; a plurality of lasers, wherein the output terminals of the plurality of power switching transistors are respectively electrically connected to the first electrodes of the plurality of lasers.

[0017] Furthermore, the second electrodes of the plurality of lasers can be electrically connected to each other.

[0018] According to another embodiment of the present invention, a laser driver chip includes a shift register, a plurality of level shifters, a plurality of latches, a plurality of drivers, and a plurality of power switches. The shift register outputs a control signal to one or more of the plurality of level shifters based on a received signal. The level shifters amplify the received control signal to produce an amplified output signal with a higher voltage. The latches receive the amplified signal from the level shifters and output it to the drivers. The drivers turn on the power switches based on the received amplified signal. The power switches are strip-shaped, and the plurality of power switches are arranged along the width direction of the strip. The signals received by the shift register include a shift clock signal, a serial data input signal, a reset control signal, and a latch clock signal.

[0019] According to another embodiment of the present invention, a laser driver chipset includes multiple laser driver chips, each of which includes a shift register, multiple level converters, multiple drivers, and multiple power switches. The shift register outputs a control signal to one or more of the multiple level converters based on a received signal. The level converters amplify the received control signal to give the amplified output signal a higher voltage. The drivers turn on the power switches based on the received amplified signal. The signals received by the shift register include a shift clock signal, a serial data input signal, a reset control signal, and a latch clock signal. The multiple shift registers of the multiple laser driver chips serially receive the serial data input signal.

[0020] According to the present invention, a single-chip integration of shift register, level converter, latch, driver, and power switch can be achieved by setting a driver chip, which can greatly reduce the area and parasitic effects of commonly used solutions, providing a feasible solution for the miniaturization and high efficiency of lidar. Furthermore, the integration of the shift register in the chip allows for the simultaneous control of multiple lasers emitting laser light. Attached Figure Description

[0021] Figure 1 This is a schematic diagram showing the driving circuit of a laser according to the prior art.

[0022] Figure 2 This is a schematic diagram illustrating a driver chip for a multi-channel laser according to an embodiment of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Obviously, the embodiments disclosed below are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the following embodiments without creative effort are within the protection scope of the present invention.

[0024] It is understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0025] Figure 2 This is a schematic diagram illustrating a driver chip for a multi-channel laser according to an embodiment of the present invention. Figure 2 In the structure shown, the circuit elements within the dashed box can be integrated into a single driver chip.

[0026] Reference Figure 2 According to an embodiment of the present invention, the driver chip of a multi-channel laser integrates a shift register, multiple level converters, multiple latches, multiple drivers, and multiple power switches.

[0027] A shift register can send one or more output control signals to multiple level shifters based on received signals. Specifically, the shift register can receive a shift clock signal CLK, a serial data input signal DIN, a reset control signal RST, and a latch clock signal RCLK. The shift clock signal CLK can input a shift clock signal into the shift register; the serial data input signal DIN allows the shift register to input data based on the shift clock signal CLK, for example, by shifting serial data at the edge of the shift clock signal CLK, where the edge can include a rising edge and / or a falling edge; the reset control signal RST can clear the data in the shift register; and the latch clock signal RCLK allows the shift register to output data in parallel. Using the shift register described above, one or more output control signals can be simultaneously sent to subsequent level shifters.

[0028] In addition, the shift register can also output a temperature detection feedback signal when the detected temperature exceeds a predetermined temperature. The predetermined temperature can be 110°C.

[0029] Furthermore, shift registers can also have ports for outputting overflowed data serially. Data can be output from the port in a first-in, first-out (FIFO) manner. For example, when a 32-bit shift register contains 32 bits of data, if another bit of data enters, the first bit that entered can be output serially.

[0030] The aforementioned port can be connected to the shift register of another driver chip. Thus, multiple shift registers can receive the serial data input signal DIN in series. Furthermore, the shift clock signal CLK, reset control signal RST, and latch clock signal RCLK can be input to multiple shift registers in parallel. Therefore, multiple shift registers can be controlled by configuring only four pins. Specifically, the shift clock signal CLK, reset control signal RST, and latch clock signal RCLK from three pins can be input to multiple shift registers in parallel, while the data input signal DIN from one pin can be input to multiple shift registers serially.

[0031] Furthermore, the shift register can be supplied with a low-voltage power supply, such as 3.3V. The shift register can be designed using CMOS devices.

[0032] The control signals E0-E31 issued from the shift register can be low-voltage signals, and can be low-voltage signals of 0-3V.

[0033] Control signals E0-E31 can be input to corresponding level converters. These level converters can convert the control signals from the shift register into medium-voltage signals. For example, they can be converted into medium-voltage signals of 0-18V. The level converters can employ known voltage conversion devices.

[0034] The output of the level converter can be electrically connected to a latch. Therefore, the signal converted to medium voltage by the level converter can pass through the latch. The latch can make the medium voltage signal converted by the level converter more stable.

[0035] The output of the latch can be electrically connected to a driver, and the signal output from the latch can pass through the driver. The driver can instantaneously increase the driving capability of the input signal. For example, the driver can increase the voltage of the input pulse signal to be greater than the turn-on voltage of the power switch.

[0036] The level shifter, latch, and driver mentioned above can all be supplied with a medium voltage. For example, they can be supplied with an 18V power supply.

[0037] The output of the driver can be electrically connected to a power switching transistor, so the signal output from the driver can be used to control the power switching transistor. For example, the length of the signal emitted by the driver can determine the duration for which the power switching transistor is turned on.

[0038] Structurally, the power switch can be a power MOSFET with a large aspect ratio and relatively low on-resistance. Existing power switches, to reduce manufacturing costs and meet performance requirements, are typically square. However, integrating multiple square power switches into a single driver chip can lead to an excessively long horizontal length due to the side-by-side arrangement of the square power switches; alternatively, arranging the power switches in multiple rows can complicate the internal circuitry of the driver chip. According to an embodiment of the present invention, forming the power switch into a rectangular shape and arranging multiple rectangular power switches with their long sides adjacent to each other can prevent the driver chip from becoming excessively long in any direction. Furthermore, the overall area of ​​the rectangular power switch is preferably not less than the area of ​​a rectangular power switch. Since the performance of the power switch is area-dependent, it is preferable that the area of ​​the power switch is not reduced by forming it into a rectangle. Alternatively, the shape of the power switch may not be a precise rectangle; it can be a strip shape with a width less than its length, and multiple power switches can be arranged along the width direction of the strip shape.

[0039] Furthermore, the output terminal of the driver can be electrically connected to the gate of the aforementioned MOS transistor, and the source or drain of the power switch can be connected to a high-voltage power supply (e.g., 50V). The other of the source and drain of the power switch can be electrically connected to the positive or negative terminal of the laser. When the power switch is turned on, the laser emits light under the influence of the high-voltage power supply. The signal emitted by the driver and the high-voltage power supply determine the energy of the detection signal emitted by the laser. The signal emitted from the power switch can directly drive one of the lasers in a multi-channel laser system. For each laser, the timing of the detection signal emitted by that laser can be controlled by controlling the on-time of the corresponding power switch.

[0040] The above text describes a scenario where the high voltage is 50V and the medium voltage is 18V, but the magnitudes of the high and medium voltages are not limited to these. For example, the high voltage could be 20V and the medium voltage could be close to or equal to 20V. Therefore, the voltage supplied to each device is not limited to the values ​​disclosed herein.

[0041] As described above, the level converter, latch, driver, and power switch can be electrically connected in sequence to form the control circuit for a single laser. According to one embodiment of this application, 32 control circuits as described above can be integrated into the lidar driver chip. Furthermore, the shift register can control the multiple control circuits as described above based on the received signal. Each of the control circuits can correspond one-to-one with a single laser in a multi-channel laser system. Therefore, the lidar driver chip described above can drive multiple channels of lasers separately.

[0042] The above description pertains to a configuration with 32 lasers, but the invention is not limited to this and can be applied equally to configurations with varying numbers of lasers. According to the invention, the number of level converters, latches, drivers, and power switches can be the same as the number of lasers in a multi-channel laser system. Furthermore, each of these devices is electrically connected to each corresponding emitter. The number of shift registers can be one.

[0043] In summary, by setting up a driver chip for lidar as described above, a single chip can be used to integrate shift registers, level converters, latches, drivers, and power switches. This can greatly reduce the area and parasitic effects of commonly used solutions, providing a feasible solution for the miniaturization and high efficiency of lidar.

[0044] Furthermore, simulation results of the scheme described above, which integrates shift registers, multiple level shifters, multiple latches, multiple drivers, and multiple power switches onto a single chip, show that the current pulse driving the laser can reach 10.79 A within 3.58 ns, the maximum current can reach 15 A, and the on-resistance is 210 milliohms. This demonstrates that the above-described technical solution improves driving efficiency.

[0045] The following describes a lidar with the driving chip described above.

[0046] The output terminal of the driver chip described above, i.e., the output terminal of each power switch, can be electrically connected to the positive terminal of each laser in the multi-channel laser. According to one embodiment of the present invention, no other circuit elements are required between the driver chip and the laser, thus greatly simplifying the circuit structure.

[0047] Multiple lasers in a multi-channel laser can be arranged side by side. The positive terminal of each laser can be connected to a driver chip, and the negative terminals of the multi-channel lasers can be electrically connected to each other and then grounded together.

[0048] Therefore, the lidar including the driving chip according to the present invention can greatly reduce the size of the multi-channel laser emitting structure.

[0049] In this invention, the case of supplying a specific voltage to the driver chip is described, but those skilled in the art will know that different voltages can be selected according to the actual situation.

[0050] According to the present invention, the shift register, multiple level shifters, multiple latches, multiple drivers, and multiple power switches are preferably integrated into a single chip. By integrating the above-mentioned devices into a single chip, the spacing between circuit components can be reduced, thereby significantly reducing the area of ​​commonly used driving schemes. Furthermore, when the various circuit components are arranged separately, more connecting lines are required, which inevitably increases parasitic effects. The solution of integrating them into a single chip in this application can reduce parasitic effects and provide a feasible solution for the miniaturization and high efficiency of lidar.

[0051] The embodiments of the apparatus and method described above are merely illustrative. The separate units described may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one position or distributed across multiple network units. Some or all of the modules can be selected to implement the technical solution of the present invention according to actual needs.

Claims

1. A driver chip for lidar, characterized in that, It includes shift registers, multiple level shifters, multiple drivers, and multiple power switches. The shift register outputs control signals to one or more of a plurality of level shifters based on the received signal. The level converter amplifies the received control signal, resulting in a higher voltage output signal. The driver turns on the power switch based on the received amplified signal; the driver determines the duration for which the power switch is turned on based on the length of the signal emitted by the driver based on the received amplified signal. The shift register receives signals including a shift clock signal, a serial data input signal, a reset control signal, and a latch clock signal. The shift clock signal is input to the shift register. The serial data input signal causes the shift register to shift the input data based on the edge of the shift clock signal. The reset control signal clears the data in the shift register. The latch clock signal causes the shift register to output data in parallel. The shift register has a port for serially outputting overflowed data.

2. The driver chip for lidar as described in claim 1, characterized in that, Also includes: A latch, located between the level converter and the driver, receives an amplified signal from the level converter and outputs it to the driver.

3. The driver chip for lidar as described in claim 2, characterized in that, The shift register is supplied with a first voltage. The level shifter, latch, and driver are supplied with a second voltage. The power switch is supplied with a third voltage. The voltage value of the third voltage is greater than or equal to the voltage value of the second voltage, and the voltage value of the second voltage is greater than the voltage value of the first voltage.

4. The driver chip for lidar as described in claim 1, characterized in that, The power switch is strip-shaped, and multiple power switches are arranged along the width of the strip.

5. The driver chip for lidar as described in claim 1, characterized in that, The power switch includes a MOS structure, and the shift register includes a CMOS structure.

6. A lidar, characterized in that, include: The driver chip for lidar as described in any one of claims 1 to 5; Multiple lasers, The output terminals of multiple power switching transistors are electrically connected to the first electrodes of multiple lasers, respectively.

7. A laser driver chip, characterized in that, It includes shift registers, multiple level shifters, multiple latches, multiple drivers, and multiple power switches. The shift register outputs control signals to one or more of a plurality of level shifters based on the received signal. The level converter amplifies the received control signal, resulting in a higher voltage output signal. The latch receives the amplified signal from the level converter and outputs it to the driver. The driver turns on the power switch based on the received amplified signal, and the driver determines the duration for which the power switch is turned on based on the length of the signal emitted by the driver based on the received amplified signal. The power switching transistors are strip-shaped, and multiple power switching transistors are arranged along the width of the strip. The shift register receives signals including a shift clock signal, a serial data input signal, a reset control signal, and a latch clock signal. The shift clock signal is input to the shift register. The serial data input signal causes the shift register to shift the input data based on the edge of the shift clock signal. The reset control signal clears the data in the shift register. The latch clock signal causes the shift register to output data in parallel. The shift register has a port for serially outputting overflowed data.

8. A laser driver chipset, characterized in that, Includes multiple laser driver chips, The laser driver chip includes a shift register, multiple level shifters, multiple drivers, and multiple power switches. The shift register outputs control signals to one or more of a plurality of level shifters based on the received signal. The level converter amplifies the received control signal, resulting in a higher voltage output signal. The driver turns on the power switch based on the received amplified signal, and the driver determines the duration for which the power switch is turned on based on the length of the signal emitted by the driver based on the received amplified signal. The shift register receives signals including a shift clock signal, a serial data input signal, a reset control signal, and a latch clock signal. The shift clock signal is input to the shift register. The serial data input signal causes the shift register to shift the input data based on the edge of the shift clock signal. The reset control signal clears the data in the shift register. The latch clock signal causes the shift register to output data in parallel. The shift register has a port for serially outputting overflowed data. Multiple shift registers of multiple laser driver chips serially receive serial data input signals, and the shift clock signal, the reset control signal, and the latch clock signal are input to the multiple shift registers in parallel.

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