Voltage switching circuit and laser radar

Abstract

A voltage switching circuit and a laser radar belong to the technical field of electronic circuits, and respectively convert a first control signal, a second control signal and a third control signal into a first driving signal, a second driving signal and a third driving signal through a first driving circuit, a second driving circuit and a third driving circuit; the first switch tube outputs the first power supply voltage to the light source according to the first driving signal so as to light the light source; the second switch tube outputs a second power supply voltage to the third switch tube according to the second driving signal; the third switch tube outputs the second power supply voltage to the light source according to the third driving signal so as to light the light source; at most one of the first switch tube and the second switch tube is switched on at the same moment; the conduction time of the first switch tube and the conduction time of the third switch tube are overlapped; the first power supply voltage is larger than the second power supply voltage. The body diode of the second switch tube and the body diode of the third switch tube are connected in opposite directions. Therefore, the accuracy and reliability of distance measurement are improved.

Description

Technical Field

[0001] The present application belongs to the field of electronic circuit technology, and in particular, relates to a voltage switching circuit and a laser radar. Background Art

[0002] With the development of LiDAR technology, the demand for laser distance measurement in vehicle-mounted main radar or intelligent network applications is getting higher and higher. Some LiDARs hope to reduce the transmitted light power to solve the problem of inaccurate ranging timing for close-range strong reflective surfaces, and some LiDARs hope to increase the transmitted light power to enhance the ranging capability for long-range low reflective surfaces; in particular, vehicle-mounted LiDARs need to measure not only farther, but also closer, reduce blind spots, and increase the ranging field of view, which means that in the process of vehicle-mounted LiDAR ranging, the light output power needs to be changed dynamically. The relevant technical solutions often use the time of capacitor charging to adjust the transmitted light power, or change the laser discharge pulse width when the constant voltage power supply is used to achieve coded light emission of strong and weak light.

[0003] The first technical solution mentioned above has unstable controllability due to the change in the capacitor charging time, which is mainly manifested in the unstable charging voltage of each channel or the inconsistent transmission power of each channel, thus affecting the correction effect; while the second technical solution mentioned above changes the discharge pulse width of the laser drive when supplying power at a constant voltage, which will lead to little difference in strong and weak light-emitting power, which is not conducive to increasing the dynamic ranging range of the vehicle-mounted laser radar and cannot meet actual usage needs.

[0004] Therefore, it is urgent to provide a voltage switching circuit to improve the dynamic ranging range of the vehicle-mounted laser radar while improving the ranging accuracy. Utility Model Content

[0005] The purpose of this application is to provide a voltage switching circuit and a laser radar, aiming to solve the problem that related laser radars are unable to improve the ranging accuracy while improving the dynamic ranging range of vehicle-mounted laser radars.

[0006] An embodiment of the present application provides a voltage switching circuit, including:

[0007] A first driving circuit is configured to receive a first control signal and convert the first control signal into a first driving signal;

[0008] a first switch tube, connected to the first drive circuit, configured to receive a first power supply voltage and output the first power supply voltage to the light source according to the first drive signal to light up the light source;

[0009] A second driving circuit is configured to receive a second control signal and convert the second control signal into a second driving signal;

[0010] a second switch tube, configured to be connected to a second power supply voltage, and output the second power supply voltage to a third switch tube according to the second drive signal;

[0011] A third driving circuit is configured to receive a third control signal and convert the third control signal into a third driving signal;

[0012] The third switch tube is connected to the first switch tube, the second switch tube and the third drive circuit, and is configured to output the second supply voltage to the light source according to the third drive signal to light up the light source;

[0013] Among them, at most one of the first switch tube and the second switch tube is turned on at the same time; and the turn-on time of the second switch tube overlaps with the turn-on time of the third switch tube; the first power supply voltage is greater than the second power supply voltage, and the body diode of the second switch tube and the body diode of the third switch tube are connected in opposite directions.

[0014] In one embodiment, it also includes:

[0015] a fourth driving circuit, configured to receive a fourth control signal and convert the fourth control signal into a fourth driving signal;

[0016] a fourth switch tube, connected to the third switch tube, the second switch tube and the fourth drive circuit, and configured to provide a charging circuit for the bootstrap capacitor in the third drive circuit and / or the bootstrap capacitor in the first drive circuit according to the fourth drive signal;

[0017] Wherein, when the fourth switch tube is turned on, the first switch tube and the third switch tube are both turned off.

[0018] In one embodiment, the fourth driving circuit includes a microprocessor, or the fourth driving circuit includes the microprocessor and a first low-side driver.

[0019] In one of the embodiments, the first driving circuit includes a first high-side driver and a second capacitor;

[0020] The power supply terminal of the first high-side driver is connected to the second power supply, and the ground terminal of the first high-side driver is connected to the power ground;

[0021] The high-side driving input terminal of the first high-side driver serves as the first control signal input terminal of the first driving circuit to receive the first control signal;

[0022] The high-side drive on-end of the first high-side driver and the high-side drive off-end of the first high-side driver are used together as the first drive signal output end of the first drive circuit, and are connected to the first switch tube to output the first drive signal;

[0023] The high-side switch source connection terminal of the first high-side driver and the first end of the second capacitor are used together as the signal ground of the first drive circuit; when the first drive signal is at a high level, the signal ground is the first supply voltage; when the first drive signal is at a low level, the signal ground is the power ground or in a floating state;

[0024] The second end of the second capacitor is connected to the bootstrap capacitor end of the first high-side driver.

[0025] In one embodiment, the first switch tube is a first NMOS tube;

[0026] The gate of the first NMOS transistor serves as the first drive signal input terminal of the first switch transistor and is connected to the first drive circuit to receive the first drive signal;

[0027] The drain of the first NMOS tube serves as a first power supply voltage input terminal of the first switch tube to access the first power supply voltage;

[0028] The source of the first NMOS tube serves as the first power supply voltage output terminal of the first switch tube, and is connected to the light source and the third switch tube to output the first power supply voltage.

[0029] In one of the embodiments, the second driving circuit includes a second low-side driver, a third field effect transistor and a third resistor;

[0030] The power supply terminal of the second low-side driver is connected to a second power supply;

[0031] The ground terminal of the second low-side driver, the negative logic level terminal IN- of the second low-side driver and the source of the third field effect transistor are connected to the power ground;

[0032] The positive logic level terminal of the second low-side driver serves as the second control signal input terminal of the second driving circuit to receive the second control signal;

[0033] The pull-up gate driving end of the second low-side driver is connected to the pull-down gate driving end of the second low-side driver and the gate of the third field effect tube, and the drain of the third field effect tube and the first end of the third resistor serve as the second driving signal output end of the second driving circuit, and are connected to the second switch tube to output the second driving signal;

[0034] The second end of the third resistor is connected to the first power source.

[0035] In one embodiment, the second switch tube is a second NMOS tube;

[0036] The gate of the second NMOS tube serves as the second drive signal input terminal of the second switch tube and is connected to the second drive circuit to receive the second drive signal;

[0037] The source of the second NMOS tube serves as a second power supply voltage input terminal of the second switch tube to access the second power supply voltage;

[0038] The drain of the second NMOS tube serves as the second power supply voltage output terminal of the second switch tube and is connected to the third switch tube to output the second power supply voltage.

[0039] In one of the embodiments, the third driving circuit includes a second high-side driver and a third capacitor;

[0040] The power supply terminal of the second high-side driver is connected to the second power supply, and the ground terminal of the second high-side driver is connected to the power ground;

[0041] The high-side driving input terminal of the second high-side driver serves as the third control signal input terminal of the third driving circuit to receive the third control signal;

[0042] The high-side drive on-end of the second high-side driver and the high-side drive off-end of the second high-side driver are used together as the third drive signal output end of the third drive circuit, and are connected to the third switch tube to output the third drive signal;

[0043] The high side switch source connection terminal of the second high side driver and the first terminal of the third capacitor are used together as the signal ground of the third driving circuit; when the third driving signal and the first driving signal are at a high level, the signal ground is the second power supply voltage; when the third driving signal or the first driving signal is at a low level, the signal ground is the power ground or in a floating state;

[0044] The second end of the third capacitor is connected to the bootstrap capacitor end of the second high-side driver.

[0045] In one embodiment, the third switch tube is a third NMOS tube;

[0046] The gate of the third NMOS tube serves as the third driving signal input terminal of the third switch tube and is connected to the third driving circuit to receive the third driving signal;

[0047] The drain of the third NMOS tube serves as the second power supply voltage input terminal of the third switch tube and is connected to the second switch tube to access the second power supply voltage;

[0048] The source of the third NMOS tube serves as the second power supply voltage output terminal of the third switch tube, and is connected to the light source and the first switch tube to output the second power supply voltage.

[0049] An embodiment of the utility model further provides a laser radar, which includes the above-mentioned voltage switching circuit.

[0050] Compared with the prior art, the embodiments of the utility model have the following beneficial effects: in the case of long-distance ranging of the vehicle-mounted laser radar, the first switch tube outputs the first power supply voltage to the light source according to the first drive signal to light up the light source. At this time, the second control signal and the third control signal are stopped, the second switch tube and the third switch tube are turned off, and the body diode of the second switch tube and the body diode of the third switch tube are connected in opposite directions, so the body diode of the second switch tube or the body diode of the third switch tube reversely cuts off the first power supply voltage, so the first power supply voltage will not be backflowed to the power supply providing the second power supply voltage and long-distance ranging is achieved; in the case of short-distance ranging of the vehicle-mounted laser radar, the first switch tube disconnects the output of the first power supply voltage according to the stopping of the first drive signal, and connects the second control signal and the third control signal, the second switch tube and the third switch tube are turned on and output the second power supply voltage to the light source to light up the light source. Since the first power supply voltage is disconnected, the first power supply voltage will not be backflowed to the power supply providing the second power supply voltage and short-distance ranging of the vehicle-mounted laser radar is achieved; thereby improving the dynamic ranging range of the vehicle-mounted laser radar while improving the accuracy and reliability of ranging. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical utility model in the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0052] Figure 1 A schematic diagram of a voltage switching circuit provided in Embodiment 2 of the present application;

[0053] Figure 2 Another structural schematic diagram of the voltage switching circuit provided in the second embodiment of the present application;

[0054] Figure 3 A partial exemplary circuit schematic diagram of a voltage switching circuit provided in Embodiment 2 of the present application;

[0055] Figure 4 Another partial exemplary circuit schematic diagram of the voltage switching circuit provided in Example 2 of the present application. DETAILED DESCRIPTION

[0056] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0057] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0058] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0059] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0060] Figure 1 Another schematic diagram of the structure of the voltage switching circuit provided by the preferred embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0061] The voltage switching circuit includes a first driving circuit 11 , a first switch tube 12 , a second driving circuit 13 , a second switch tube 14 , a third driving circuit 15 and a third switch tube 16 .

[0062] The first driving circuit 11 is configured to receive the first control signal PWM1 and convert the first control signal PWM1 into a first driving signal.

[0063] The first switch tube 12 is connected to the first drive circuit 11 , and is configured to receive the first power supply voltage VIN1 , and output the first power supply voltage VIN1 to the light source according to the first drive signal, so as to light up the light source.

[0064] The second driving circuit 13 is configured to receive the second control signal PWM2 and convert the second control signal PWM2 into a second driving signal.

[0065] The second switch tube 14 is configured to be connected to the second power supply voltage VIN2 and output the second power supply voltage VIN2 to the third switch tube 16 according to the second driving signal.

[0066] The third driving circuit 15 is configured to receive the third control signal PWM3 and convert the third control signal PWM3 into a third driving signal.

[0067] The third switch tube 16 is connected to the first switch tube 12, the second switch tube 14 and the third driving circuit 15, and is configured to output the second power supply voltage VIN2 to the light source according to the third driving signal to light up the light source;

[0068] Among them, at most one of the first switch tube 12 and the second switch tube 14 is turned on at the same time; and the turn-on time of the first switch tube 12 and the turn-on time of the third switch tube 16 overlap; the first power supply voltage VIN1 is greater than the second power supply voltage VIN2, and the body diode of the second switch tube 14 and the body diode of the third switch tube 16 are connected in opposite directions.

[0069] The first switch tube and the third switch tube may be NMOS or PMOS.

[0070] like Figure 2 As shown, the voltage switching circuit further includes a fourth driving circuit 17 and a fourth switch tube 18 .

[0071] The fourth driving circuit 17 is configured to receive the fourth control signal PWM4 and convert the fourth control signal PWM4 into a fourth driving signal.

[0072] The fourth switch tube 18 is connected to the third switch tube 16, the second switch tube 14 and the fourth drive circuit 17, and is configured to provide a charging circuit for the bootstrap capacitor in the third drive circuit 15 and / or the bootstrap capacitor in the first drive circuit 11 according to the fourth drive signal.

[0073] When the fourth switch tube 18 is turned on, the first switch tube 12 and the third switch tube 16 are both turned off.

[0074] Since the fourth switch tube 18 provides a charging circuit for the bootstrap capacitor in the third drive circuit 15 and the bootstrap capacitor in the first drive circuit 11 according to the fourth drive signal, the possibility of insufficient charging of the bootstrap capacitor in the third drive circuit 15 and the bootstrap capacitor in the first drive circuit 11 is reduced, thereby improving the reliability of the voltage switching circuit.

[0075] The fourth driving circuit 17 may include a microprocessor, or the fourth driving circuit may include the microprocessor and a first low-side driver.

[0076] Figure 3 A partial exemplary circuit structure of a voltage switching circuit provided by an embodiment of the utility model is shown. For the sake of convenience, only the part related to the embodiment of the utility model is shown, which is described in detail as follows:

[0077] The fourth drive circuit 17 includes a first low-side driver U4; the power supply terminal VDD of the first low-side driver U4 is connected to the second power supply VBB; the ground terminal GND of the first low-side driver U4 and the negative logic level terminal IN- of the first low-side driver U4 are connected to the power ground; the positive logic level terminal IN+ of the first low-side driver U4 serves as the fourth control signal input terminal of the fourth drive circuit 17 to access the fourth control signal PWM4; the pull-up gate drive terminal OUH of the first low-side driver U4 and the pull-down gate drive terminal OUTL of the first low-side driver U4 serve together as the fourth drive signal output terminal of the fourth drive circuit 17, and are connected to the fourth switch tube 18 to output the fourth drive signal.

[0078] The fourth switch tube 18 is a fourth NMOS tube N4. The gate of the fourth NMOS tube N4 is used as the fourth drive signal input terminal of the fourth switch tube 18, and is connected to the fourth drive circuit 17 to receive the fourth drive signal; the drain of the fourth NMOS tube N4 is connected to the first switch tube 12, the third switch tube 16 and the light source, and the source of the fourth NMOS tube N4 is connected to the power ground.

[0079] The first driving circuit 11 includes a first high-side driver U1 and a second capacitor C2 .

[0080] The power supply terminal VDD of the first high-side driver U1 is connected to the second power supply VBB, and the ground terminal VSS of the first high-side driver U1 is connected to the power ground; the high-side drive input terminal HI of the first high-side driver U1 serves as the first control signal input terminal of the first drive circuit 11 to access the first control signal PWM1; the high-side drive start terminal HOH of the first high-side driver U1 and the high-side drive stop terminal HOL of the first high-side driver U1 serve as the first drive signal output terminal of the first drive circuit 11, and are connected to the first switch tube 12 to output the first drive signal; the high-side switch source connection terminal HS of the first high-side driver U1 and the first end of the second capacitor C2 serve as the signal ground of the first drive circuit 11; when the first drive signal is at a high level, the signal ground is the first power supply voltage VIN1; when the first drive signal is at a low level, the signal ground is the power ground or floating; the second end of the second capacitor C2 is connected to the bootstrap capacitor terminal HB of the first high-side driver U1.

[0081] The first high-side driver U1 is used to implement the first driving circuit 11, thereby realizing high-side driving of the first switch tube 12, and the circuit is simple and reliable.

[0082] The first switch tube 12 is a first NMOS tube N1;

[0083] The gate of the first NMOS tube N1 serves as the first drive signal input terminal of the first switch tube 12, and is connected to the first drive circuit 11 to receive the first drive signal; the drain of the first NMOS tube N1 serves as the first power supply voltage input terminal of the first switch tube 12 to receive the first power supply voltage VIN1; the source of the first NMOS tube N1 serves as the first power supply voltage output terminal of the first switch tube 12, and is connected to the light source and the third switch tube 16 to output the first power supply voltage VIN1.

[0084] exist Figure 3 In the embodiment, the second driving circuit 13 includes a second low-side driver U5, a third field effect transistor M3 and a third resistor R3.

[0085] The power supply terminal VDD of the second low-side driver U5 is connected to the second power supply VBB; the ground terminal GND of the second low-side driver U5, the negative logic level terminal IN- of the second low-side driver U5 and the source of the third field effect transistor M3 are connected to the power ground; the positive logic level terminal IN+ of the second low-side driver U5 serves as the second control signal input terminal of the second drive circuit 13 to access the second control signal PWM2; the pull-up gate drive terminal OUH of the second low-side driver U5 is connected to the pull-down gate drive terminal OUTL of the second low-side driver U5 and the gate of the third field effect transistor M3, the drain of the third field effect transistor M3 and the first end of the third resistor R3 serve as the second drive signal output terminal of the second drive circuit 13, and are connected to the second switch tube 14 to output the second drive signal; the second end of the third resistor R3 is connected to the first power supply VAA.

[0086] The second driving signal is pulled up by the third resistor R3, and the high-side driving is realized by the low-side driver. The common cathode of the light source can be grounded and the heat dissipation speed and reliability are improved, and the shutdown speed is improved and the circuit volume is reduced.

[0087] It should be noted that the second driving circuit 13 can also be implemented in the following manner:

[0088] like Figure 4 As shown, the second driving circuit 13 includes a first high-voltage low-side driver U7.

[0089] The power supply terminal of the first high-voltage low-side driver U7 is connected to the first power supply VAA; the logic level terminal IN of the first high-voltage low-side driver U7 is used as the second control signal input terminal of the second drive circuit 14 to access the second control signal PWM2; the gate drive terminal OUT of the first high-voltage low-side driver U7 is used as the second drive signal output terminal of the second drive circuit 13, connected to the second switch tube 14 to output the second drive signal; the ground terminal GND of the first high-voltage low-side driver U7 is connected to the power ground. Among them, the logic level terminal IN of the first high-voltage low-side driver U7 includes the positive logic level terminal IN+ of the first high-voltage low-side driver U7 and the negative logic level terminal IN- of the first high-voltage low-side driver U7, or the logic level terminal IN of the first high-voltage low-side driver U7 only includes the positive logic level terminal IN+ of the first high-voltage low-side driver U7.

[0090] It should be emphasized that Figure 4 Except for the second drive circuit, other module circuits are Figure 3 same.

[0091] The second switch tube 14 is a second NMOS tube N2.

[0092] The gate of the second NMOS tube N2 serves as the second drive signal input terminal of the second switch tube 14, and is connected to the second drive circuit 13 to receive the second drive signal; the source of the second NMOS tube N2 serves as the second power supply voltage input terminal of the second switch tube 14 to receive the second power supply voltage VIN2; the drain of the second NMOS tube N2 serves as the second power supply voltage output terminal of the second switch tube 14, and is connected to the third switch tube 16 to output the second power supply voltage VIN2.

[0093] The third driving circuit 15 includes a second high-side driver U6 and a third capacitor C3.

[0094] The power supply terminal VDD of the second high side driver U6 is connected to the second power supply VBB, and the ground terminal VSS of the second high side driver U6 is connected to the power ground; the high side driver input terminal HI of the second high side driver U6 serves as the third control signal input terminal of the third driving circuit 15 to access the third control signal PWM3; the high side driver start terminal HOH of the second high side driver U6 and the high side driver stop terminal HOL of the second high side driver U6 serve together as the third driving signal output terminal of the third driving circuit 15, and are connected to the third switch tube 16 to output the third driving signal; the high side switch source connection terminal HS of the second high side driver U6 and the first end of the third capacitor C3 serve together as the signal ground of the third driving circuit 15; when the third driving signal and the first driving signal are at a high level, the signal ground is the second power supply voltage VIN2; when the third driving signal or the first driving signal is at a low level, the signal ground is the power ground or floating state; the second end of the third capacitor C3 is connected to the bootstrap capacitor terminal HB of the second high side driver U6.

[0095] The second high-side driver U6 is used to implement the third driving circuit 15, thereby realizing high-side driving of the third switch tube 16, and the circuit is simple and reliable.

[0096] The third switch tube 16 is a third NMOS tube N3.

[0097] The gate of the third NMOS tube N3 serves as the third drive signal input terminal of the third switch tube 16, and is connected to the third drive circuit 15 to receive the third drive signal; the drain of the third NMOS tube N3 serves as the second power supply voltage input terminal of the third switch tube 16, and is connected to the second switch tube 14 to receive the second power supply voltage VIN2; the source of the third NMOS tube N3 serves as the second power supply voltage output terminal of the third switch tube 16, and is connected to the light source and the first switch tube 12 to output the second power supply voltage VIN2.

[0098] The following is a combination of working principles Figure 3 and Figure 4 As shown for further explanation:

[0099] exist Figure 3In the case of long-distance ranging of the vehicle-mounted laser radar, the high-side driver input terminal HI of the first high-side driver U1 is connected to the first control signal PWM1, and the first high-side driver U1 converts the first control signal PWM1 into a first drive signal and outputs it from the high-side driver start terminal HOH of the first high-side driver U1 and the high-side driver close terminal HOL of the first high-side driver U1 to the gate of the first NMOS tube N1, the first NMOS tube N1 is turned on, and the first power supply voltage VIN1 is output from the source of the first NMOS tube N1 to the light source to light up the light source, and at the same time, the second control signal PWM2 and the third control signal PWM3 are stopped, and the second low-side driver U5 stops the second control signal PWM2 The second NMOS tube N2 is turned off, and the second high-side driver U2 stops converting the third control signal PWM3 into the third drive signal; the third NMOS tube N3 is turned off, and stops outputting the second power supply voltage VIN2 from the drain of the third NMOS tube N3. Since the first power supply voltage VIN1 is greater than the second power supply voltage VIN2, the body diode of the second switch tube 14 and the body diode of the third switch tube 16 are connected in opposite directions. Therefore, the body diode of the second switch tube 14 or the body diode of the third switch tube 16 reversely cuts off the first power supply voltage VIN1. Therefore, the first power supply voltage VIN1 will not flow back to the power supply providing the second power supply voltage VIN2, and long-distance ranging is achieved.

[0100] In the case of short-range ranging of the vehicle-mounted laser radar, the first control signal PWM1 is stopped from being connected, the first high-side driver U1 stops converting the first control signal PWM1 into the first drive signal, the first NMOS tube N1 disconnects the output of the first power supply voltage VIN1 according to the stopping of the first drive signal, and the positive logic level terminal IN+ of the second low-side driver U5 is connected to the second control signal PWM2, the second low-side driver U5 converts the second control signal PWM2 into a second PWM signal and outputs it from the pull-up gate drive terminal OUH of the second low-side driver U5 to the gate of the third field effect tube M3, the third field effect tube M3 converts the second PWM signal into a second drive signal and outputs it from the drain of the third field effect tube M3 To the gate of the second NMOS tube N2, the second NMOS tube N2 outputs the second power supply voltage VIN2 from the drain of the second NMOS tube N2 to the drain of the third NMOS tube N3 according to the second driving signal; the high-side driving input terminal HI of the second high-side driver U6 is connected to the third control signal PWM3, the second high-side driver U6 converts the third control signal PWM3 into a third driving signal and outputs it from the high-side driving start terminal HOH of the second high-side driver U6 and the high-side driving close terminal HOL of the second high-side driver U6 to the gate of the third NMOS tube N3, and the third NMOS tube N3 outputs the second power supply voltage VIN2 from the source of the third NMOS tube N3 to the light source according to the third driving signal to light up the light source. Since the first power supply voltage VIN1 is disconnected, the first power supply voltage VIN1 will not flow back to the power supply that provides the second power supply voltage VIN2 and the short-range ranging of the vehicle-mounted laser radar is realized.

[0101] It should be noted that when the fourth NMOS tube N4 is turned on, the first NMOS tube N1 and the third NMOS tube N3 are both turned off. At this time, the third capacitor C3 and the second capacitor C2 are charged. When the first NMOS tube N1 is turned on, the second capacitor C2 bootstraps the first power supply voltage VIN1 according to the first charging voltage after charging, so as to supply power to the first high-side driver U1, thereby lifting the first control signal PWM1 and outputting the first drive signal to achieve high-side driving of the first NMOS tube N1. Similarly, when the third NMOS tube N3 is turned on, the third capacitor C3 bootstraps the second power supply voltage VIN2 according to the second charging voltage after charging, so as to supply power to the second high-side driver U6, thereby lifting the third control signal PWM3 and outputting the third drive signal to achieve high-side driving of the third NMOS tube N3.

[0102] exist Figure 4In the embodiment, the positive logic level terminal IN+ of the first high-voltage low-side driver U7 is connected to the second control signal PWM2, and the first high-voltage low-side driver U7 converts the second control signal PWM2 into a second drive signal and outputs the second drive signal from the gate drive terminal OUT of the first high-voltage low-side driver U7 to the gate of the second NMOS tube N2; Figure 4 The circuits and circuit principles of other modules in Figure 3 The same is not repeated here.

[0103] An embodiment of the utility model further provides a laser radar, which includes the above-mentioned voltage switching circuit.

[0104] In the embodiment of the utility model, a first drive circuit accesses a first control signal and converts the first control signal into a first drive signal; a first switch tube accesses a first power supply voltage and outputs the first power supply voltage to a light source according to the first drive signal to light up the light source; a second drive circuit accesses a second control signal and converts the second control signal into a second drive signal; a second switch tube accesses a second power supply voltage and outputs the second power supply voltage to a third switch tube according to the second drive signal; a third drive circuit accesses a third control signal and converts the third control signal into a third drive signal; the third switch tube outputs the second power supply voltage to the light source according to the third drive signal to light up the light source; wherein, at most one of the first switch tube and the second switch tube is turned on at the same time; and the turn-on time of the first switch tube and the turn-on time of the third switch tube overlap; the first power supply voltage is greater than the second power supply voltage, and the body diode of the second switch tube and the body diode of the third switch tube are connected in opposite directions; thereby improving the dynamic ranging range of the vehicle-mounted laser radar while improving the accuracy and reliability of ranging.

[0105] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0106] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A voltage switching circuit, characterized in that: include: A first driving circuit is configured to receive a first control signal and convert the first control signal into a first driving signal; a first switch tube, connected to the first drive circuit, configured to receive a first power supply voltage and output the first power supply voltage to the light source according to the first drive signal to light up the light source; A second driving circuit is configured to receive a second control signal and convert the second control signal into a second driving signal; a second switch tube, configured to be connected to a second power supply voltage, and output the second power supply voltage to a third switch tube according to the second drive signal; A third driving circuit is configured to receive a third control signal and convert the third control signal into a third driving signal; The third switch tube is connected to the first switch tube, the second switch tube and the third drive circuit, and is configured to output the second supply voltage to the light source according to the third drive signal to light up the light source; Among them, at most one of the first switch tube and the second switch tube is turned on at the same time; and the turn-on time of the second switch tube overlaps with the turn-on time of the third switch tube; the first power supply voltage is greater than the second power supply voltage, and the body diode of the second switch tube and the body diode of the third switch tube are connected in opposite directions.

2. The voltage switching circuit according to claim 1, wherein: Also includes: a fourth driving circuit, configured to receive a fourth control signal and convert the fourth control signal into a fourth driving signal; a fourth switch tube, connected to the third switch tube, the first switch tube and the fourth drive circuit, and configured to provide a charging circuit for the bootstrap capacitor in the third drive circuit and / or the bootstrap capacitor in the first drive circuit according to the fourth drive signal; Wherein, when the fourth switch tube is turned on, the first switch tube and the third switch tube are both turned off.

3. The voltage switching circuit according to claim 2, wherein: The fourth driving circuit includes a microprocessor, or the fourth driving circuit includes a microprocessor and a first low-side driver.

4. The voltage switching circuit according to any one of claims 1 to 3, characterized in that: The first driving circuit includes a first high-side driver and a second capacitor; The power supply terminal of the first high-side driver is connected to the second power supply, and the ground terminal of the first high-side driver is connected to the power ground; The high-side driving input terminal of the first high-side driver serves as the first control signal input terminal of the first driving circuit to receive the first control signal; The high-side drive on-end of the first high-side driver and the high-side drive off-end of the first high-side driver are used together as the first drive signal output end of the first drive circuit, and are connected to the first switch tube to output the first drive signal; The high-side switch source connection terminal of the first high-side driver and the first end of the second capacitor are used together as the signal ground of the first drive circuit; when the first drive signal is at a high level, the signal ground is the first supply voltage; when the first drive signal is at a low level, the signal ground is the power ground or in a floating state; The second end of the second capacitor is connected to the bootstrap capacitor end of the first high-side driver.

5. The voltage switching circuit according to any one of claims 1 to 3, characterized in that: The first switch tube is a first NMOS tube; The gate of the first NMOS transistor serves as the first drive signal input terminal of the first switch transistor and is connected to the first drive circuit to receive the first drive signal; The drain of the first NMOS tube serves as a first power supply voltage input terminal of the first switch tube to access the first power supply voltage; The source of the first NMOS tube serves as the first power supply voltage output terminal of the first switch tube, and is connected to the light source and the third switch tube to output the first power supply voltage.

6. The voltage switching circuit according to any one of claims 1 to 3, characterized in that: The second driving circuit includes a second low-side driver, a third field effect transistor and a third resistor; The power supply terminal of the second low-side driver is connected to a second power supply; The ground terminal of the second low-side driver, the negative logic level terminal IN- of the second low-side driver and the source of the third field effect transistor are connected to the power ground; The positive logic level terminal of the second low-side driver serves as the second control signal input terminal of the second driving circuit to receive the second control signal; The pull-up gate driving end of the second low-side driver is connected to the pull-down gate driving end of the second low-side driver and the gate of the third field effect tube, and the drain of the third field effect tube and the first end of the third resistor serve as the second driving signal output end of the second driving circuit, and are connected to the second switch tube to output the second driving signal; The second end of the third resistor is connected to the first power source.

7. The voltage switching circuit according to any one of claims 1 to 3, characterized in that: The second switch tube is a second NMOS tube; The gate of the second NMOS tube serves as the second drive signal input terminal of the second switch tube and is connected to the second drive circuit to receive the second drive signal; The source of the second NMOS tube serves as a second power supply voltage input terminal of the second switch tube to access the second power supply voltage; The drain of the second NMOS tube serves as the second power supply voltage output terminal of the second switch tube and is connected to the third switch tube to output the second power supply voltage.

8. The voltage switching circuit according to any one of claims 1 to 3, characterized in that: The third driving circuit includes a second high-side driver and a third capacitor; The power supply terminal of the second high-side driver is connected to the second power supply, and the ground terminal of the second high-side driver is connected to the power ground; The high-side driving input terminal of the second high-side driver serves as the third control signal input terminal of the third driving circuit to receive the third control signal; The high-side drive on-end of the second high-side driver and the high-side drive off-end of the second high-side driver are used together as the third drive signal output end of the third drive circuit, and are connected to the third switch tube to output the third drive signal; The high side switch source connection terminal of the second high side driver and the first terminal of the third capacitor are used together as the signal ground of the third driving circuit; When the third driving signal and the first driving signal are at a high level, the signal ground is the second power supply voltage; When the third driving signal or the first driving signal is at a low level, the signal ground is a power ground or in a floating state; The second end of the third capacitor is connected to the bootstrap capacitor end of the second high-side driver.

9. The voltage switching circuit according to any one of claims 1 to 3, characterized in that: The third switch tube is a third NMOS tube; The gate of the third NMOS tube serves as the third driving signal input terminal of the third switch tube and is connected to the third driving circuit to receive the third driving signal; The drain of the third NMOS tube serves as the second power supply voltage input terminal of the third switch tube and is connected to the second switch tube to access the second power supply voltage; The source of the third NMOS tube serves as the second power supply voltage output terminal of the third switch tube, and is connected to the light source and the first switch tube to output the second power supply voltage.

10. A laser radar, characterized in that: The laser radar includes a voltage switching circuit as described in any one of claims 1 to 9.

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