Laser radar chip, laser radar ranging device and sweeping robot

Abstract

The utility model discloses a laser radar chip, a laser radar ranging device and a sweeping robot, which are applied to the field of laser radars. According to the invention, the input end of an avalanche photodiode is electrically connected with a first voltage source, and the output end of the avalanche photodiode is electrically connected with the inverted input end of a transimpedance amplifier; the in-phase input end of the transimpedance amplifier is electrically connected with the second voltage source, and the output end of the transimpedance amplifier is electrically connected with the inverted input end of the high-speed comparator; the positive phase input end of the high-speed comparator is electrically connected with the third voltage source, and the output end of the high-speed comparator serves as the first output end of the laser radar chip. The integrated design is adopted for the devices, the size and the manufacturing cost of the laser radar chip are reduced to a certain extent, the signal-to-noise ratio is increased, and the signal oscillation amplitude is reduced.

Description

Technical Field

[0001] The utility model relates to the field of laser radar, in particular to a laser radar chip, a laser radar distance measuring device and a sweeping robot. Background Art

[0002] LiDAR is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of a target. It has been combined with a large number of daily life devices and is widely used in human daily life, such as sweeping robots, self-driving vehicles, drones, etc.

[0003] At present, laser radar usually uses two principles for ranging. One is the triangulation radar principle: using geometric relationships and imaging methods to measure distance, the distance between emission and reception is not easy to be too small, so the overall volume is relatively large, and under this principle, the distance is inversely proportional to the accuracy, with high accuracy at close range and poor accuracy at long distances. The other is the direct time of flight measurement principle: this principle emits a laser pulse to the object to be measured, which enters the receiving circuit after reflection from the object. The receiving circuit generally uses an avalanche photodiode (APD) as a photodetector, and then passes through a current-to-voltage transimpedance amplifier (TIA), and then passes through a high-speed comparator (COMP) to obtain an echo pulse, which enters the time-to-digital converter (TDC) to obtain the corresponding flight time, and finally uses the relationship between the propagation speed of light and time to obtain the measured distance. However, the APD, TIA, and COMP involved in this method are all separate components. Since APD involves relatively high voltage scenarios, and since the integration process used by APD, TIA, and COMP is different, it cannot be integrated, so the overall volume of the receiving circuit is relatively large. The large size of the laser radar affects the daily use of its living equipment to a certain extent.

[0004] In view of the above technologies, seeking a lidar chip that integrates an avalanche photodiode, a transimpedance amplifier and a high-speed comparator is an urgent problem to be solved by technical personnel in this field. Utility Model Content

[0005] The purpose of the utility model is to provide a laser radar chip, a laser radar ranging device and a sweeping robot, which are used to solve the problem that avalanche photodiodes, transimpedance amplifiers and high-speed amplifiers cannot be integrated in the prior art, resulting in a large circuit volume and affecting the use of the equipment in daily life.

[0006] In order to solve the above technical problems, the utility model provides a laser radar chip, including: an avalanche photodiode, a transimpedance amplifier, and a high-speed comparator;

[0007] Wherein, the input end of the avalanche photodiode is electrically connected to the first voltage source, and the output end of the avalanche photodiode is electrically connected to the inverting input end of the transimpedance amplifier;

[0008] The non-inverting input terminal of the transimpedance amplifier is electrically connected to the second voltage source, and the output terminal of the transimpedance amplifier is electrically connected to the inverting input terminal of the high-speed comparator;

[0009] The non-phase input terminal of the high-speed comparator is electrically connected to the third voltage source, and the output terminal of the high-speed comparator serves as the first output terminal of the laser radar chip.

[0010] Preferably, it also includes: a light filtering unit; an avalanche photodiode including an effective photosensitive surface and an electrode;

[0011] Among them, the filter part is arranged on the effective photosensitive surface, and the projection of the filter part on the plane where the effective photosensitive surface is located completely covers the effective photosensitive surface and does not contact the covering electrode; the avalanche photodiode and the filter part are packaged as a whole.

[0012] Preferably, the avalanche photodiode is a high-voltage reverse diode; the laser radar chip adopts small chip technology, and packages the avalanche photodiode, transimpedance amplifier and high-speed comparator into a whole by sealing; and the transimpedance amplifier is arranged between the avalanche photodiode and the high-speed comparator.

[0013] In order to solve the above technical problems, the present application also provides a laser radar ranging device, including the above laser radar chip.

[0014] Preferably, the laser radar ranging device further comprises: a first adjustment circuit;

[0015] Wherein, the first adjustment circuit includes a first resistor and a first capacitor;

[0016] The first end of the first resistor is electrically connected to the inverting input terminal of the transimpedance amplifier of the laser radar chip, and the second end of the first resistor is electrically connected to the output terminal of the transimpedance amplifier; the first capacitor is connected in parallel to both ends of the first resistor.

[0017] Or the first adjustment circuit includes: a second resistor, a third resistor and a fourth resistor;

[0018] A first end of the second resistor is electrically connected to the inverting input terminal of the transimpedance amplifier, and a second end of the second resistor is electrically connected to a first end of the third resistor and a first end of the fourth resistor;

[0019] The second end of the third resistor is electrically connected to the output end of the transimpedance amplifier;

[0020] The second end of the fourth resistor is grounded.

[0021] Preferably, the laser radar ranging device further comprises: a second adjustment circuit;

[0022] Wherein, the second adjustment circuit includes: a fifth resistor, a sixth resistor, a seventh resistor and a MOS tube;

[0023] The first end of the fifth resistor is electrically connected to the first end of the sixth resistor, the first end of the seventh resistor and the inverting output end of the high-speed comparator, and the second end of the fifth resistor is electrically connected to the electrical end of the third voltage source;

[0024] The second end of the sixth resistor is grounded;

[0025] The second end of the seventh resistor is electrically connected to the source of the MOS tube;

[0026] The gate of the MOS tube is electrically connected to the level output terminal, and the drain of the MOS tube is grounded.

[0027] Preferably, the laser radar ranging device further comprises: a microprocessing unit and a pulse laser driver;

[0028] Wherein, the output end of the microprocessing unit is electrically connected to the input end of the pulse laser driver;

[0029] The input end of the microprocessor unit is electrically connected to the first output end of the laser radar chip.

[0030] Preferably, it also includes: a time-to-digital converter;

[0031] Among them, the first input end of the time digital converter is electrically connected to the output end of the microprocessing unit, the second input end of the time digital converter is electrically connected to the first output end of the laser radar chip, and the output end of the time digital converter is electrically connected to the input end of the microprocessing unit.

[0032] In order to solve the above technical problems, the present application also provides a sweeping robot, including the above-mentioned laser radar ranging device.

[0033] The utility model provides a laser radar chip, including: an avalanche photodiode, a transimpedance amplifier, and a high-speed comparator; wherein the input end of the avalanche photodiode is electrically connected to the first voltage source, and the output end of the avalanche photodiode is electrically connected to the inverting input end of the transimpedance amplifier; the in-phase input end of the transimpedance amplifier is electrically connected to the second voltage source, and the output end of the transimpedance amplifier is electrically connected to the inverting input end of the high-speed comparator; the non-inverting input end of the high-speed comparator is electrically connected to the third voltage source, and the output end of the high-speed comparator serves as the first output end of the laser radar chip. It can be seen that the present application reduces the volume and production cost of the laser radar chip to a certain extent by adopting an integrated design for the avalanche photodiode, the transimpedance amplifier, and the high-speed comparator, and improves the signal-to-noise ratio and reduces the signal oscillation amplitude through its own transimpedance amplifier and high-speed comparator. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present utility model, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A structural diagram of a laser radar chip provided in an embodiment of the present application;

[0036] Figure 2 A layout diagram of a laser radar chip provided in an embodiment of the present application;

[0037] Figure 3 A solar radiation spectrum distribution diagram provided for an embodiment of the present application;

[0038] Figure 4 A spectrum diagram of a narrow-band filter provided in an embodiment of the present application;

[0039] Figure 5 A first circuit diagram of a first adjustment circuit provided in an embodiment of the present application;

[0040] Figure 6 A second circuit diagram of the first adjustment circuit provided in an embodiment of the present application;

[0041] Figure 7 A circuit diagram of a second adjustment circuit provided in an embodiment of the present application;

[0042] Figure 8 A structural diagram of a complete laser radar ranging device provided in an embodiment of the present application;

[0043] Fig. 9 A cross-sectional view of a complete laser radar ranging device provided in an embodiment of the present application;

[0044] Fig.10 A top view of a complete laser radar ranging device provided in an embodiment of the present application;

[0045] Fig.11 A flow chart of ranging provided in an embodiment of the present application;

[0046] Fig.12 Schematic diagram of a sweeping robot provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the utility model.

[0048] The core of the utility model is to provide a laser radar chip, a laser radar ranging device and a sweeping robot.

[0049] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0050] Figure 1 A structure diagram of a laser radar chip provided in an embodiment of the present application, such as Figure 1 As shown, it includes: an avalanche photodiode 1, a transimpedance amplifier 3, and a high-speed comparator 4;

[0051] Wherein, the input end of the avalanche photodiode 1 is electrically connected to the first voltage source, and the output end of the avalanche photodiode 1 is electrically connected to the inverting input end of the transimpedance amplifier 3;

[0052] The non-inverting input terminal of the transimpedance amplifier 3 is electrically connected to the second voltage source, and the output terminal of the transimpedance amplifier 3 is electrically connected to the inverting input terminal of the high-speed comparator 4;

[0053] The non-inverting input terminal of the high-speed comparator 4 is electrically connected to the third voltage source, and the output terminal of the high-speed comparator 4 serves as the first output terminal of the laser radar chip.

[0054] In a specific embodiment, the avalanche photodiode 1 is used to obtain a light intensity signal. When the avalanche photodiode 1 is in a high gain state, photogenerated carriers are generated, and a current signal proportional to the intensity of the light signal on the avalanche photodiode 1 is output. The transimpedance amplifier 3 is used to amplify the current signal output by the avalanche photodiode 1 and output a corresponding analog voltage signal. The high-speed comparator 4 compares the analog voltage signal output by the transimpedance amplifier 3 with its own threshold value to obtain a digital signal of "0" or "1", and inputs it into the time-to-digital converter for distance calculation.

[0055] Among them, it should be noted that since the avalanche photodiode 1 is a high-voltage device, it is necessary to apply a high voltage of more than 100 volts to the cathode of the avalanche photodiode 1 when it works normally. Therefore, the process of the avalanche photodiode 1 is very different from the tape-out process of a general low-voltage integrated circuit chip. Therefore, one tape-out process cannot be used. Instead, only small chip technology can be used to seal the wafers of different chips in the same package through the form of sealing. As a preferred embodiment, the avalanche photodiode 1 selects a silicon avalanche photodiode.

[0056] It should also be noted that the present application does not limit the specific signal selection of the avalanche photodiode 1, the transimpedance amplifier 3 and the high-speed comparator 4, which can be set according to the needs of the user.

[0057] The utility model provides a laser radar chip, including: an avalanche photodiode, a transimpedance amplifier, and a high-speed comparator; wherein the input end of the avalanche photodiode is electrically connected to the first voltage source, and the output end of the avalanche photodiode is electrically connected to the inverting input end of the transimpedance amplifier; the in-phase input end of the transimpedance amplifier is electrically connected to the second voltage source, and the output end of the transimpedance amplifier is electrically connected to the inverting input end of the high-speed comparator; the non-inverting input end of the high-speed comparator is electrically connected to the third voltage source, and the output end of the high-speed comparator serves as the first output end of the laser radar chip. It can be seen that the present application reduces the volume and production cost of the laser radar chip to a certain extent by adopting an integrated design for the avalanche photodiode, the transimpedance amplifier, and the high-speed comparator, and improves the signal-to-noise ratio and reduces the signal oscillation amplitude through its own transimpedance amplifier and high-speed comparator.

[0058] Based on the above embodiments, as a preferred embodiment, Figure 1 and Figure 2 As shown, the laser radar chip also includes: a filter unit 2; an avalanche photodiode 1 including an effective photosensitive surface and an electrode 6;

[0059] The filter unit 2 is arranged on the effective photosensitive surface, and the projection of the filter unit 2 on the plane where the effective photosensitive surface is located completely covers the effective photosensitive surface, and the electrode 6 is a convex structure relative to the photosensitive surface, so that the filter unit 2 can fit and cover the effective photosensitive surface, thereby ensuring the filtering effect of the filter unit 2, the filter unit 2 does not contact the covering electrode 6; and the avalanche photodiode and the filter unit 2 are packaged as a whole. The filter unit 2 can be a narrow-band filter or a protective glass.

[0060] And as a preferred embodiment, the avalanche photodiode 1 is a high-voltage reverse diode; the laser radar chip adopts small chip technology, and packages the avalanche photodiode 1, the transimpedance amplifier 3, and the high-speed comparator 4 into a whole through sealing, and the transimpedance amplifier 3 is arranged between the avalanche photodiode 1 and the high-speed comparator 4.

[0061] In a specific embodiment, the working principle of a laser radar chip provided in the embodiment of the present application is: when the light signal passes through the receiving optical lens, Figure 1 After the filter section 2 represented by the dotted frame in the figure, the background light is filtered out, and only the light consistent with the central wavelength of the filter section 2 can penetrate the filter section 2 and reach the avalanche photodiode 1. Since the avalanche photodiode 1 is in a high-gain working state (usually M=100 or so), after the photon is captured by the avalanche photodiode 1, photogenerated carriers are generated, and a current signal proportional to the intensity of the light signal is output. When the current signal enters the transimpedance amplifier 3, it is amplified after transimpedance amplification and a corresponding analog voltage signal is output. The amplitude of the voltage signal is: V=I*Rf (I is the photocurrent size, Rf is the external resistance value). Finally, the high-speed comparator 4 compares the analog voltage signal output by the transimpedance amplifier 3 with its own threshold value to obtain a digital signal of "0" or "1", and inputs it into the time-to-digital converter for distance calculation.

[0062] In a specific embodiment, Figure 2 As shown, the electrode 6 is an avalanche photodiode electrode. In this layout, the avalanche photodiode 1, the filter 2 and the avalanche photodiode electrode 6 are on the left side of the transimpedance amplifier 3, and the high-speed comparator 4 is on the right side of the transimpedance amplifier 3. This layout arrangement is more in line with the requirements, because the working principle of its laser radar ranging device is: light enters the avalanche photodiode 1 through the filter 2, then passes through the transimpedance amplifier 3, and finally enters the high-speed comparator 4.

[0063] Among them, in the solar luminescence spectrum, 905nm is a window, and the radiation energy of this wavelength is relatively low, such as Figure 3 Therefore, in order to reduce the interference of sunlight on the measurement, as a preferred embodiment, the filter part 2 can use a narrow-band filter, and the narrow-band filter uses a narrow-band filter with a spectrum of 905nm. The narrower the channel range of the narrow-band filter, the less background light is transmitted, and the higher the signal-to-noise ratio is. Figure 4 This is the spectrum of the narrowband filter at 905nm.

[0064] It should be noted that the layout method provided in this application is only one possible implementation method, but is not limited to only this implementation method and can be set according to the needs of the user.

[0065] The present application provides a layout method for internal components of a laser radar ranging device. Under this layout, the area size of the laser radar chip is reduced to a certain extent, as well as the use of connecting wires when connecting components, thereby reducing costs.

[0066] To solve the above technical problems, the present application also provides a laser radar ranging device, including the above laser radar chip, and in addition, as a preferred embodiment, it also includes: a first adjustment circuit; wherein the first adjustment circuit includes two options, the first option, such as Figure 5 As shown, the first adjustment circuit includes a first resistor R1 and a first capacitor C1; the first end of the first resistor R1 is electrically connected to the inverting input end of the transimpedance amplifier 3 of the laser radar chip, and the second end of the first resistor R1 is electrically connected to the output end of the transimpedance amplifier 3; the first capacitor C1 is connected in parallel to both ends of the first resistor R1; the second option, such as Figure 6 As shown: the first adjustment circuit includes: a second resistor R2, a third resistor R3 and a fourth resistor R4; the first end of the second resistor R2 is electrically connected to the inverting input end of the transimpedance amplifier 3, and the second end of the second resistor R2 is electrically connected to the first end of the third resistor R3 and the first end of the fourth resistor R4; the second end of the third resistor R3 is electrically connected to the output end of the transimpedance amplifier 3; the second end of the fourth resistor R4 is grounded.

[0067] for Figure 5 and Figure 6 The first adjustment circuit in the structure can adjust the external resistance value of the transimpedance amplifier 3. Figure 6 For example, its advantage is that a relatively large equivalent impedance can be obtained by using a small resistance value (because the larger the resistance value, the greater the thermal noise). It can be seen that the thermal noise generated by the resistance is reduced by using a small resistance. Among them, Rf (external resistance value) = R2+R3+R2*R3 / R4.

[0068] In addition, it also includes a second adjustment circuit; Figure 7As shown, the second adjustment circuit includes: a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a MOS transistor G1; the first end of the fifth resistor R5 is electrically connected to the first end of the sixth resistor R6, the first end of the seventh resistor R7 and the inverting output end of the high-speed comparator 4, and the second end of the fifth resistor R5 is electrically connected to the third voltage source VCC; the second end of the sixth resistor R6 is grounded; the second end of the seventh resistor R7 is electrically connected to the source of the MOS transistor G1; the gate of the MOS transistor G1 is electrically connected to the level output end SW, and the drain of the MOS transistor G1 is grounded. The second adjustment circuit under this structure can adjust the threshold of the high-speed comparator 4. Among them, when SW is selected as L (low level), the first MOS tube G1 (N-channel MOSFE tube) is not turned on, and at this time, the reverse input end of the high-speed comparator 4 is used as the reference level of the high-speed comparator 4 and is calculated according to the following formula: V-=VCC*R6 / (R5+R7); when SW is selected as H (high level), the first MOS tube G1 (N-channel MOSFE tube) is turned on, the sixth resistor R6 and the seventh resistor R7 are connected in parallel, and the parallel resistance is RL: RL=(R6*R7 / (R6+R7)), then at this time, the reverse input end is used as the reference level of the high-speed comparator 4 and is calculated according to the following formula: V-=VCC*RL / (R+R5).

[0069] It should be noted that this application is only one possible implementation method, but is not limited to this implementation method and can be adjusted according to user needs.

[0070] The utility model provides a laser radar ranging device, including: a laser radar chip, and the laser radar chip includes: an avalanche photodiode, a transimpedance amplifier, and a high-speed comparator; wherein the input end of the avalanche photodiode is electrically connected to the first voltage source, and the output end of the avalanche photodiode is electrically connected to the inverting input end of the transimpedance amplifier; the in-phase input end of the transimpedance amplifier is electrically connected to the second voltage source, and the output end of the transimpedance amplifier is electrically connected to the inverting input end of the high-speed comparator; the positive input end of the high-speed comparator is electrically connected to the third voltage source, and the output end of the high-speed comparator serves as the first output end of the laser radar chip. It can be seen that the present application reduces the volume and production cost of the laser radar chip to a certain extent by adopting an integrated design for the avalanche photodiode, the transimpedance amplifier and the high-speed comparator, and improves the signal-to-noise ratio and reduces the signal oscillation amplitude through its own transimpedance amplifier and high-speed comparator. At the same time, under the action of the first adjustment circuit and the second adjustment circuit, the transimpedance gain and the comparator threshold can be adjusted to expand the use scenario of the laser radar ranging device provided by the present application.

[0071] In order to solve the above technical problems, the present application also provides a laser radar ranging device, such as Figure 8As shown: it includes: a laser radar chip 7 (including an avalanche photodiode 1, a filter 2, a transimpedance amplifier 3, and a high-speed comparator 4), a pulse laser driver 8, a time digital converter 9, and a microprocessor 10, and the connection relationship is: the output end of the microprocessor 10 is electrically connected to the input end of the pulse laser driver 8; the input end of the microprocessor 10 is electrically connected to the first output end of the laser radar chip 7; the first input end of the time digital converter 9 is electrically connected to the output end of the microprocessor 10, the second input end of the time digital converter 9 is electrically connected to the first output end of the laser radar chip 7, and the output end of the time digital converter 9 is electrically connected to the input end of the microprocessor 10. On this basis, in order to ensure the use of the laser radar ranging device, an object to be measured 11 is also required. The principle of its complete laser radar ranging device is: after the pulse laser driver 8 receives the initial signal (start) sent by the microprocessor 10, it transmits a pulse laser signal to the object to be measured 11. After the laser pulse signal is reflected by the object to be measured 11, it is sent to the radar chip 7. In the radar chip 7, it first passes through the filter 2 to filter out the background light, and then reaches the avalanche photodiode 1. The avalanche photodiode 1 generates photogenerated carriers and outputs a current signal proportional to the intensity of the light signal. When the current signal enters the transimpedance amplifier 3, it is amplified by the transimpedance amplifier 3 and outputs the corresponding analog voltage signal. Finally, it enters the high-speed comparator 4 and outputs a digital signal (stop). The digital signal (stop) and the initial signal (start) enter the time-to-digital converter (TDC) 9. According to the time corresponding to the digital signal (stop) and the time corresponding to the initial signal (start), the time result (TOF) can be determined, and finally the time result (TOF) is sent to the microprocessing unit 10, so that the microprocessing unit 10 can determine the corresponding distance according to the time result.

[0072] Among them, as a preference, the pulse laser driver 8 generally selects a pulse laser driver with a wavelength of 905nm.

[0073] In practical applications, when the laser radar ranging device is mounted on a rotating platform of a brushless motor, the motor drives the ranging module to rotate, and the laser radar scanning and mapping can be realized. The structural cross-section diagram is shown in the figure. Fig. 9 As shown, the top view is Fig.10 As shown. Among them, 8 is a pulse laser driver, 7 is a laser radar chip (including an avalanche photodiode 1, a filter 2, a transimpedance amplifier 3, and a high-speed comparator 4), 9 is a time-to-digital converter, 10 is a microcontroller unit, 12 is a brushless motor (which can increase the service life of the radar), 13 is a laser radar protective cover; 14 is a transmitting lens, 15 is a receiving lens, 16 is a transmitting and receiving partition (to prevent the transmitting laser from being directly reflected by the cover to the receiving chip to cause interference); 17 is a bottom plate (data receiving and processing, motor control).

[0074] To sum up, the complete ranging process is as follows Fig.11 As shown:

[0075] S10: Start.

[0076] S11: Hardware and software reset.

[0077] S12: Configure hardware and software data.

[0078] S13: The microprocessor sends an initialization command.

[0079] S14: The microprocessor unit sends an initial signal to the pulse laser driver and the time-to-digital converter.

[0080] S15: The laser radar chip receives the reflected initial signal and outputs a corresponding digital signal.

[0081] S16: The time digital converter determines a time result according to the initial signal and the digital signal.

[0082] S17: Determine whether the time result overflows, if so, proceed to step S18, if not, return to step S13.

[0083] S18: The microprocessing unit obtains the time result of the time digital converter.

[0084] S19: The microprocessing unit determines the distance based on the time result and the speed of light.

[0085] S20: End.

[0086] The specific embodiments corresponding to steps S10-S20 in the embodiments of the present application are the same as the embodiments described above, and the present application will not elaborate on them here.

[0087] In summary, the laser radar chip 7 (including the avalanche photodiode 1, the filter unit 2, the transimpedance amplifier 3, and the high-speed comparator 4) and the laser radar device have the following characteristics:

[0088] 1. The integrated avalanche photodiode 1 and the filter unit 2 are beneficial to improving the sunlight resistance and the adaptability of the laser radar;

[0089] 2. The effective photosensitive surface of the internally integrated avalanche photodiode 1 (silicon avalanche photodiode) is 500μm, which can allow the optomechanical structure to withstand large stress changes. And the reverse avalanche voltage range of the avalanche photodiode 1 (silicon avalanche photodiode) is: 120V~160V.

[0090] 3. When the gain of avalanche photodiode 1 is 100, it has an extremely low dark current of 0.3nA.

[0091] 4. The transimpedance amplifier 3 has a high bandwidth of 7 GHz and an adjustable transimpedance gain, which is convenient for adjusting the transimpedance gain and is suitable for different measurement ranges.

[0092] 5. The high-speed comparator 4 has a small transmission delay of only 4 ns, which can well match the shaping of the analog signal output by the transimpedance amplifier 3, thereby outputting a pulse signal with a steep edge, providing a more accurate timing accuracy for the subsequent time digital converter 9.

[0093] Therefore, the laser radar chip and the filter part in the laser radar ranging device provided by this application can be used in situations with strong background light. The transimpedance amplifier has the characteristics of large bandwidth (7GHz), high gain (20KΩ), and low noise. At the same time, the fast overload recovery time greatly matches the application requirements of the laser radar, and the separate output of the analog signal facilitates the expansion requirements of different gains. The high-speed comparator has the advantages of low transmission delay and adjustable threshold, which greatly meets the flexibility of the design.

[0094] When the above-mentioned laser radar distance measuring device is used in life, it can be placed in a sweeping robot, such as Fig.12 As shown, the laser radar ranging device is installed on the top of the sweeping robot, which expands the scanning angle of the sweeping robot. In addition, the overall volume of the laser radar ranging device is small, that is, the overall volume of the sweeping robot is small, so that it can flexibly clean the places where dust is difficult to clean such as under the sofa and bed, and thus cause dust to accumulate. In addition, the sweeping robot also has the advantages of the above-mentioned laser radar chip or laser radar ranging device, which will not be elaborated in this application.

[0095] The above is a detailed introduction to a laser radar chip, a laser radar ranging device and a sweeping robot provided by the utility model. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can be referenced to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

[0096] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A laser radar chip, characterized in that: include: Avalanche photodiodes, transimpedance amplifiers, high-speed comparators; Wherein, the input end of the avalanche photodiode is electrically connected to the first voltage source, and the output end of the avalanche photodiode is electrically connected to the inverting input end of the transimpedance amplifier; The non-inverting input terminal of the transimpedance amplifier is electrically connected to the second voltage source, and the output terminal of the transimpedance amplifier is electrically connected to the inverting input terminal of the high-speed comparator; The non-inverting input terminal of the high-speed comparator is electrically connected to a third voltage source, and the output terminal of the high-speed comparator serves as the first output terminal of the laser radar chip.

2. The laser radar chip according to claim 1, characterized in that: Also includes: Filter unit; the avalanche photodiode includes an effective photosensitive surface and an electrode; Wherein, the filter part is arranged on the effective photosensitive surface, and the projection of the filter part on the plane where the effective photosensitive surface is located completely covers the effective photosensitive surface and does not contact or cover the electrode; and the avalanche photodiode and the filter part are packaged as a whole.

3. The laser radar chip according to claim 1 or 2, characterized in that: The avalanche photodiode is a high-voltage reverse diode; the laser radar chip adopts small chip technology, and packages the avalanche photodiode, the transimpedance amplifier and the high-speed comparator into a whole by sealing, and the transimpedance amplifier is arranged between the avalanche photodiode and the high-speed comparator.

4. A laser radar ranging device, characterized in that: Comprising the laser radar chip described in any one of claims 1-3.

5. The laser radar ranging device according to claim 4, characterized in that: Also includes: a first adjustment circuit; Wherein, the first adjustment circuit includes a first resistor and a first capacitor; The first end of the first resistor is electrically connected to the inverting input end of the transimpedance amplifier of the laser radar chip, and the second end of the first resistor is electrically connected to the output end of the transimpedance amplifier; the first capacitor is connected in parallel to both ends of the first resistor.

6. The laser radar ranging device according to claim 4, characterized in that: Also includes: a first adjustment circuit; Wherein, the first adjustment circuit comprises: a second resistor, a third resistor and a fourth resistor; The first end of the second resistor is electrically connected to the inverting input terminal of the transimpedance amplifier, and the second end of the second resistor is electrically connected to the first end of the third resistor and the first end of the fourth resistor; The second end of the third resistor is electrically connected to the output end of the transimpedance amplifier; A second end of the fourth resistor is grounded.

7. The laser radar ranging device according to claim 4, characterized in that: Also includes: a second adjustment circuit; Wherein, the second adjustment circuit comprises: a fifth resistor, a sixth resistor, a seventh resistor and a MOS tube; Wherein, the first end of the fifth resistor is electrically connected to the first end of the sixth resistor, the first end of the seventh resistor and the inverting output end of the high-speed comparator, and the second end of the fifth resistor is electrically connected to the third voltage source; The second end of the sixth resistor is grounded; The second end of the seventh resistor is electrically connected to the source of the MOS tube; The gate of the MOS tube is electrically connected to the level output terminal, and the drain of the MOS tube is grounded.

8. The laser radar ranging device according to any one of claims 4 to 7, characterized in that: Also includes: microprocessing unit and pulsed laser driver; Wherein, the output end of the microprocessing unit is electrically connected to the input end of the pulse laser driver; The input end of the microprocessor unit is electrically connected to the first output end of the laser radar chip.

9. The laser radar ranging device according to claim 8, characterized in that: Also includes: Time to digital converter; Among them, the first input end of the time digital converter is electrically connected to the output end of the microprocessing unit, the second input end of the time digital converter is electrically connected to the first output end of the laser radar chip, and the output end of the time digital converter is electrically connected to the input end of the microprocessing unit.

10. A sweeping robot, characterized in that: It comprises the laser radar ranging device described in any one of claims 4 to 9; the laser radar ranging device is arranged on the top of the sweeping robot.

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