A global shutter for laser radar array

Abstract

The present invention discloses a laser radar array global shutter, which relates to the field of integrated circuit design. In the laser radar array global shutter of the present invention, when laser emission occurs, the START switch is synchronously closed, the Vs voltage generates a ramp voltage by time integration starting from 0V, and then the Vs voltage is converted to the Vout voltage by a unit gain buffer, so that the Vout voltage = the Vs voltage; in the initial state, the S_00-S_mn array switches are all in the closed state. When the laser receiver detects the reflected laser, the laser receiver sends a STOP signal and opens the START switch. At this time, the corresponding voltage in the S_00-S_mn array switches is latched and saved. The present invention converts time information into voltage information and stores it. The time information is converted and read one by one through row selection. All arrays share the same time integrator, reducing the inconsistency error caused by multiple integrators.

Description

Technical Field

[0001] The present invention belongs to the field of integrated circuit design, and in particular relates to a global shutter of a laser radar array. Background Art

[0002] Traditional DTof LiDAR implementations involve emitting laser light, which is reflected by an object to a receiver. The time difference between emission and reception is recorded to calculate the distance between the object and the detected object. Due to the high speed of light, the data volume is relatively small for single-point laser ranging chips. One LiDAR receiver receiving one piece of time information easily solves the problem of data reception and conversion. However, for large arrays, the data volume is substantial, requiring many LiDAR receivers to receive the time information and complete the conversion, which consumes a significant amount of circuit resources and is quite difficult to implement. Therefore, for large-area laser array chips, we need to address the following issues:

[0003] (1) How to capture a large amount of time information data in a short period of time;

[0004] (2) How to store time information data;

[0005] (3) How to reduce data conversion modules;

[0006] (4) How to ensure the consistency of data conversion modules.

[0007] Therefore, in order to solve the above problems, it is of great significance to provide a global shutter for a lidar array. Summary of the Invention

[0008] The present invention provides a global shutter for a laser radar array, which solves the above problems.

[0009] To solve the above technical problems, the present invention is achieved through the following technical solutions:

[0010] A laser radar array global shutter of the present invention includes a current mirror IS, a START switch, an integrated operation method device, a C1 capacitor, and a laser receiver;

[0011] The two ends of the current mirror IS are connected to the laser receiver and the current mirror IS respectively. The current mirror IS is connected to the START switch. One end of the C1 capacitor is connected to the START switch through wiring to achieve switch coordination, and the other end is grounded. The positive input end of the integrated arithmetic method is connected to the wire between the START switch and the C1 capacitor, and the generated voltage is the Vs voltage. The negative input end and the output end of the integrated arithmetic method are combined and connected to the array switch of m columns and n rows, and the voltage generated in the combined and connected line segment is the Vout voltage.

[0012] The array switches of m columns and n rows are numbered S_00-S_mn, and the corresponding voltage values ​​on the array switches S_00-S_mn are V_00-V_mn respectively;

[0013] When the laser is emitted, the START switch is closed synchronously, and the Vs voltage is integrated over time starting from 0V to generate a ramp voltage, and then the Vs voltage is converted to the Vout voltage by the unity gain buffer, so that the Vout voltage = Vs voltage;

[0014] In the initial state, the S_00-S_mn array switches are all in the closed state. When the laser receiver detects the reflected laser, the corresponding laser receiver sends a STOP signal and opens the corresponding START switch. At this time, the corresponding voltage in the S_00-S_mn array switch is latched and saved, realizing the conversion of time information into voltage information and saving it.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention converts time information into voltage information and stores it. The time information is converted and read one by one through row selection, and can be converted and read row by row through column selection. In this way, for an m-column and n-row array, only n rows of ADCs need to be converted, reducing the ADC by a factor of m. All arrays of the present invention share the same time integrator, reducing the inconsistency error caused by multiple integrators.

[0017] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 This is a schematic diagram of the structural principle of a global shutter of a laser radar array according to the present invention;

[0020] Figure 2 This is a schematic diagram of the technical solution of traditional lidar. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] like Figure 2 As shown, the traditional solution uses one TDC (time-digital-converter) for each laser receiver to convert time information into digital form. However, it is not possible for one TDC to simultaneously receive multiple time information. Therefore, for an mn array globe shutter, m*n TDCs are required to complete the conversion. This leads to many problems in design and manufacturing, such as high power consumption and large chip area.

[0023] The circuit of this technical solution realizes the function of storing time information, which can be converted and read row by row through column selection. In this way, for an array with m columns and n rows, only n rows of ADC conversion are required, which reduces the ADC by m times. All arrays of this circuit share the same time integrator, reducing the inconsistency error caused by multiple integrators. This is achieved specifically through the following technical means:

[0024] See also Figure 1 As shown, a laser radar array global shutter of the present invention includes a current mirror IS, a START switch, an integrated operation method, a C1 capacitor, and a laser receiver;

[0025] The two ends of the current mirror IS are connected to the laser receiver and the current mirror IS respectively. The current mirror IS is connected to the START switch. One end of the C1 capacitor is connected to the START switch through wiring to achieve switch coordination, and the other end is grounded. The positive input end of the integrated arithmetic method is connected to the wire between the START switch and the C1 capacitor, and the generated voltage is the Vs voltage. The negative input end and the output end of the integrated arithmetic method are combined and connected to the array switch of m columns and n rows, and the voltage generated in the combined and connected line segment is the Vout voltage.

[0026] The array switches of m columns and n rows are numbered S_00-S_mn, and the corresponding voltage values ​​on the array switches S_00-S_mn are V_00-V_mn respectively;

[0027] When the laser is emitted, the START switch is closed synchronously, and the Vs voltage is integrated over time starting from 0V to generate a ramp voltage, and then the Vs voltage is converted to the Vout voltage by the unity gain buffer, so that the Vout voltage = Vs voltage;

[0028] In the initial state, the S_00-S_mn array switches are all in the closed state. When the laser receiver detects the reflected laser, the corresponding laser receiver sends a STOP signal and opens the corresponding START switch. At this time, the corresponding voltage in the S_00-S_mn array switch is latched and saved, realizing the conversion of time information into voltage information and saving it.

[0029] Beneficial effects:

[0030] The present invention converts time information into voltage information and stores it. The time information is converted and read one by one through row selection, and can be converted and read row by row through column selection. In this way, for an m-column and n-row array, only n rows of ADCs need to be converted, reducing the ADC by a factor of m. All arrays of the present invention share the same time integrator, reducing the inconsistency error caused by multiple integrators.

[0031] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A laser radar array global shutter, characterized in that: Including current mirror IS, START switch, integrated operation method device, C1 capacitor, laser receiver; The two ends of the current mirror IS are respectively connected to the laser receiver and the START switch; one end of the C1 capacitor is connected to the START switch through wiring to achieve switch coordination, and the other end is grounded; the positive input end of the integrated operation method is connected to the wire between the START switch and the C1 capacitor, and the generated voltage is the Vs voltage; the negative input end and the output end of the integrated operation method are combined and connected to the array switch of m columns and n rows, and the voltage generated in the combined and connected line segment is the Vout voltage; The array switches of m columns and n rows are numbered S_00-S_mn, and the corresponding voltage values ​​on the array switches S_00-S_mn are V_00-V_mn respectively; When the laser is emitted, the START switch is closed synchronously, and the Vs voltage is integrated over time starting from 0V to generate a ramp voltage, and then the Vs voltage is converted to the Vout voltage by the unity gain buffer, so that the Vout voltage = Vs voltage; In the initial state, the S_00-S_mn array switches are all in the closed state. When the laser receiver detects the reflected laser, the corresponding laser receiver sends a STOP signal and opens the corresponding START switch. At this time, the corresponding voltage in the S_00-S_mn array switch is latched and saved, realizing the conversion of time information into voltage information and saving it.

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