Direct driver applied to ultrasonic sensor

Abstract

The invention provides a direct driver applied to an ultrasonic sensor. The direct driver applied to the ultrasonic sensor comprises a level conversion circuit, a control circuit, a gate driving circuit and a direct driving circuit which are connected in sequence, when the level conversion circuit receives a low-voltage logic control signal, the level conversion circuit outputs a logic control signal conforming to the working voltage of the direct driver; the control circuit converts the received logic control signal into a multi-path control signal; the direct drive circuit forms different output paths when receiving different control signals, so that the direct drive circuit outputs positive and negative alternating voltage pulses to drive the ultrasonic sensor; the application does not need to introduce a negative pressure design, reduces the design difficulty, reduces the substrate noise, and reduces the latch risk.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic equipment, and in particular to a direct driver applied to an ultrasonic sensor. Background Art

[0002] Driving a piezoelectric ultrasonic sensor requires alternating positive and negative voltage pulses. The alternating application of positive and negative voltages is to cause the piezoelectric material to undergo compression and stretching during the generation and reception of ultrasonic waves. This alternating mechanical stress is necessary for transmitting and receiving ultrasonic waves. If only positive or negative voltage is applied, the piezoelectric material can only deform in one direction and cannot generate effective ultrasonic waves. Therefore, the driver integrated in the ultrasonic reversing radar chip also needs to generate alternating positive and negative voltage pulses. The existing ultrasonic reversing radar chip driver part can be divided into two types: direct drive type and non-direct drive type. The direct drive type can generate positive and negative alternating, high-voltage pulse signals that can directly drive the piezoelectric ultrasonic sensor by the driver integrated inside the chip. The non-direct drive chip requires an external intermediate frequency transformer, which is more expensive.

[0003] The existing direct drive type uses positive and negative voltage drive, that is, one pin of the ultrasonic sensor is directly grounded, and the other pin is driven by the positive and negative voltage output by the ultrasonic chip. However, due to the positive feedback effect, this method forms a low-impedance path between the power supply and the ground, thereby causing abnormal current to flow, which may cause circuit failure or even chip burning, namely the latch-up effect. Summary of the invention

[0004] The present disclosure provides a direct driver applied to an ultrasonic sensor to at least solve the above technical problems existing in the prior art.

[0005] According to a first aspect of the present disclosure, there is provided a direct driver applied to an ultrasonic sensor, the direct driver comprising: a level conversion circuit, a control circuit, a gate drive circuit and a direct drive circuit connected in sequence;

[0006] The level conversion circuit is used to output a logic control signal that conforms to the working voltage of the direct driver when receiving a low voltage logic control signal;

[0007] The control circuit is used to convert the received logic control signal into a multi-channel control signal;

[0008] The gate drive circuit is used to switch and output a corresponding control signal according to the working mode of the direct drive circuit;

[0009] The direct drive circuit is used to form a corresponding output path according to the received control signal, so that the direct drive circuit outputs positive and negative alternating voltage pulses to drive the ultrasonic sensor;

[0010] Among them, when the direct drive circuit is in the first working mode, it receives the first multiple control signals output by the gate drive circuit, forms a first output path and outputs a positive voltage pulse; when the direct drive circuit is in the second working mode, it receives the second multiple control signals output by the gate drive circuit, forms a second output path and outputs a negative voltage pulse.

[0011] In one possible implementation, the direct drive circuit includes a positive drive terminal and a negative drive terminal;

[0012] When the direct drive circuit forms a third output path according to the received multi-path control signals so that the direct drive circuit forms a third working mode, the positive drive terminal and the negative drive terminal of the direct drive circuit are both floating;

[0013] When the direct drive circuit forms a fourth output path according to the received multi-path control signals so that the direct drive circuit forms a fourth operation mode, the positive drive terminal and the negative drive terminal of the direct drive circuit are both grounded.

[0014] In one possible implementation manner, the direct drive circuit further includes a first controllable switch tube, a second controllable switch tube, a third controllable switch tube, and a fourth controllable switch tube; the multi-channel control signal includes a first control signal, a second control signal, a third control signal, and a fourth control signal;

[0015] The control end of the first controllable switch tube receives a first control signal, the first end of the first controllable switch tube and the first end of the third controllable switch tube are both connected to the working voltage, and the second end of the first controllable switch tube and the second end of the second controllable switch tube are both connected to the positive driving end; the control end of the second controllable switch tube receives a second control signal, the first end of the second controllable switch tube and the first end of the fourth controllable switch tube are both grounded; the control end of the third controllable switch tube receives a third control signal, and the second end of the third controllable switch tube and the second end of the fourth controllable switch tube are both connected to the negative driving end; the control end of the fourth controllable switch tube receives a fourth control signal.

[0016] In one possible implementation manner, the first controllable switch tube and the third controllable switch tube are both P-type field effect tubes;

[0017] The second controllable switch tube and the fourth controllable switch tube are both N-type field effect tubes.

[0018] In one embodiment, the gate drive circuit includes a PMOS gate drive circuit and an NMOS gate drive circuit; the input end of the PMOS gate drive circuit and the input end of the NMOS gate drive circuit are both connected to the output end of the control circuit, and the output end of the PMOS gate drive circuit and the output end of the NMOS gate drive circuit are both connected to the direct drive circuit;

[0019] The PMOS gate drive circuit is used to turn on the P-type field effect transistor that needs to be turned on according to the working mode of the direct drive circuit;

[0020] The NMOS gate drive circuit is used to turn on the N-type field effect transistor that needs to be turned on according to the working mode of the direct drive circuit.

[0021] In one possible implementation, the direct drive circuit receives the first multi-path control signal output by the gate drive circuit in the first working mode, forms a first output path and outputs a positive voltage pulse, including:

[0022] The first controllable switch tube receives a first control signal and is turned on, the fourth controllable switch tube receives a fourth control signal and is turned on, the positive drive end is connected to the working voltage through the first controllable switch tube, and the negative drive end is grounded through the fourth controllable switch tube, so that the direct drive circuit outputs a positive voltage pulse;

[0023] The direct drive circuit receives the second multi-path control signal output by the gate drive circuit in the second working mode, forms a second output path and outputs a negative voltage pulse, including:

[0024] The second controllable switch tube receives a second control signal and is turned on, the third controllable switch tube receives a third control signal and is turned on, the positive drive end is grounded through the second controllable switch tube, and the negative drive end is connected to the working voltage through the third controllable switch tube, so that the direct drive circuit outputs a negative voltage pulse.

[0025] In one possible implementation manner, when the direct drive circuit forms a third working mode, the first controllable switch tube, the second controllable switch tube, the third controllable switch tube and the fourth controllable switch tube are all turned off;

[0026] When the direct drive circuit forms a fourth working mode, the second controllable switch tube receives a second control signal and is turned on, and the fourth controllable switch tube receives a fourth control signal and is turned on.

[0027] In one possible implementation, the control circuit includes:

[0028] A controller and a two-phase non-overlapping clock, wherein the controller is connected to the two-phase non-overlapping clock;

[0029] The two-phase non-overlapping clock is used to insert a dead time when the controller switches the voltage pulses in the positive and negative directions.

[0030] In one possible implementation, the direct drive circuit adopts an H-bridge structure.

[0031] In one possible implementation, the controller includes a plurality of pins, and a plurality of the plurality of pins are used to send multiple control signals to the direct drive circuit.

[0032] According to a second aspect of the present disclosure, a driver chip is provided, using the direct driver for an ultrasonic sensor as described in any one of the above embodiments.

[0033] The direct driver applied to the ultrasonic sensor disclosed in the present invention does not introduce a negative pressure design, thereby reducing design difficulty, substrate noise, and latchup risk.

[0034] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, in which:

[0036] In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0037] Figure 1 The structure of the direct driver of the ultrasonic sensor according to the embodiment of the present disclosure is shown in FIG. Figure 1 ;

[0038] Figure 2 A schematic diagram of the structure of a signal direct drive circuit according to an embodiment of the present disclosure is shown;

[0039] Figure 3 The structure of the direct driver of the ultrasonic sensor according to the embodiment of the present disclosure is shown in FIG. Figure 2 ;

[0040] Figure 4 A pulse schematic diagram of a direct driver of an ultrasonic sensor applied to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0041] In order to make the purpose, features, and advantages of the present disclosure more obvious and easy to understand, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0042] Existing commercial ultrasonic reversing radar chips usually use piezoelectric ultrasonic drivers. In order to enable the reversing radar to detect a longer distance, the ultrasonic sensor needs to generate ultrasonic pulses with a higher sound pressure, and the high sound pressure pulses require the ultrasonic sensor to be driven by a larger voltage.

[0043] The working principle of the transceiver piezoelectric ultrasonic sensor used with the ultrasonic reversing radar chip is based on the piezoelectric effect. When voltage is applied to the piezoelectric chip, the chip will deform, and the deformation will propagate in the form of mechanical waves during transmission. This piezoelectric effect is reversible. When receiving, the ultrasonic wave will deform the piezoelectric material again, thereby generating an electrical signal.

[0044] Direct drive can be divided into two types: positive and negative voltage drive and bridge drive. Other direct drive competitors all use positive and negative voltage drive, that is, one pin of the ultrasonic sensor is directly grounded, and the other pin is driven by the positive and negative voltage output of the ultrasonic chip. The bridge drive requires connecting both pins of the sensor to the chip, and the chip connects the two pins alternately to the power supply and ground to achieve the effect equivalent to positive and negative voltage drive.

[0045] In summary, the direct-drive ultrasonic reversing radar chip does not require an external intermediate-circuit transformer, which reduces the volume of the finished reversing radar when used by customers and reduces the number of peripheral devices, and has advantages in terms of application cost. The present application provides a direct driver for ultrasonic sensors, which uses a bridge direct drive and does not contain a negative voltage design, thereby reducing the design difficulty. At the same time, since the design does not contain a negative voltage, the substrate is directly grounded without the need to connect to a negative voltage, which reduces the noise coupled into the circuit by the negative voltage substrate (reducing the anti-noise design requirements of other circuits, and also reducing the additional area of ​​the layout isolation part caused by the introduction of negative voltage), and also reduces the risk of latch-up in the integrated circuit.

[0046] The direct driver for an ultrasonic sensor provided by the present application is described below with reference to the accompanying drawings.

[0047] As attached Figure 1 As shown, an embodiment of the present application provides a direct driver applied to an ultrasonic sensor, the direct driver comprising: a level conversion circuit 1, a control circuit 2, a gate drive circuit 3 and a direct drive circuit 4 connected in sequence;

[0048] The level conversion circuit 1 is used to output a logic control signal that meets the working voltage of the direct driver when receiving a low voltage logic control signal;

[0049] The control circuit 2 is used to convert the received logic control signal into a multi-channel control signal;

[0050] The gate drive circuit 3 is used to output a corresponding control signal according to the working mode switching of the direct drive circuit 4;

[0051] The direct drive circuit 4 is used to form a corresponding output path according to the received control signal, so that the direct drive circuit 4 outputs positive and negative alternating voltage pulses to drive the ultrasonic sensor;

[0052] Among them, when the direct drive circuit 4 is in the first working mode, it receives the first multi-channel control signal output by the gate drive circuit 3, forms a first output path and outputs a positive voltage pulse; when the direct drive circuit 4 is in the second working mode, it receives the second multi-channel control signal output by the gate drive circuit 3, forms a second output path and outputs a negative voltage pulse.

[0053] The direct driver for ultrasonic sensors provided in the present application has a power supply voltage that, after receiving a voltage signal, inputs a voltage logic control signal into a level conversion circuit 1 using a logic chip. If the level conversion circuit 1 receives a low-voltage logic control signal, the low-voltage logic control signal is converted into a voltage logic control signal that can drive the direct driver for internal use, for example, converting 1.8V into 5V. The level conversion circuit 1 sends the voltage logic control signal to the control circuit 2, and the control circuit 2 converts the received voltage logic control signal into a multi-channel control signal for controlling the direct driver. The gate drive circuit 3 outputs the corresponding control signal according to the working mode switching of the direct drive circuit, and the direct driver enters different working modes according to the different received control signals, wherein the gate drive circuit 3 outputs the corresponding control signal according to the working mode switching of the direct drive circuit 4; the direct drive circuit 4 forms a corresponding output path according to the received control signal, so that the direct drive circuit 4 outputs positive and negative alternating voltage pulses to drive the ultrasonic sensor; wherein, in the first working mode, the direct drive circuit 4 receives the first multi-channel control signal output by the gate drive circuit 3, forms a first output path and outputs a positive voltage pulse; in the second working mode, the direct drive circuit 4 receives the second multi-channel control signal output by the gate drive circuit 3, forms a second output path and outputs a negative voltage pulse. Thus, the positive and negative alternating voltage pulses are output to the ultrasonic sensor, so that the ultrasonic sensor can detect a farther distance.

[0054] It can be understood that the multi-channel control signal in the present application, according to the preset working mode of the direct drive circuit 4, the gate drive circuit performs level conversion on the control signal of the corresponding working mode in the multi-channel control signal, thereby outputting the control signal of the corresponding combination, because different combinations can make the direct drive circuit 4 enter different working modes, for example, when receiving the A control signal and the B control signal, the direct drive circuit 4 enters the first working mode and outputs a positive voltage pulse, when receiving the C control signal and the D control signal, the direct drive circuit 4 enters the second working mode and outputs a negative voltage pulse, the first working mode and the second working mode are alternately performed to realize the alternating output of positive and negative voltage pulses, thereby driving the ultrasonic sensor to achieve detection at a longer distance. The ultrasonic sensor driven by the direct driver provided in the present application can be used as a reversing radar with a longer detection distance.

[0055] In some embodiments, the direct drive circuit 4 includes a positive drive terminal and a negative drive terminal;

[0056] When the direct drive circuit 4 forms a third output path according to the received multi-path control signals so that the direct drive circuit 4 forms a third working mode, the positive drive terminal and the negative drive terminal of the direct drive circuit 4 are both floating;

[0057] When the direct drive circuit 4 forms a fourth output path according to the received multi-path control signals so that the direct drive circuit 4 forms a fourth operation mode, the positive drive terminal and the negative drive terminal of the direct drive circuit 4 are both grounded.

[0058] In the present application, the direct drive circuit 4 can also enter the third working mode according to the received multi-channel control signal, at which time the positive drive end and the negative drive end of the direct drive circuit 4 are both floating; the direct drive circuit 4 can also enter the fourth working mode according to the received multi-channel control signal, at which time the positive drive end and the negative drive end of the direct drive circuit 4 are both grounded. It should be noted that the working mode in which the output end of the direct drive circuit 4 is floating is used to receive ultrasonic signals, and the positive and negative output ends are completely suspended, which helps the ultrasonic sensor to resonate the piezoelectric film after receiving the ultrasonic echo. Grounding is used to briefly ground the positive and negative drive ends after the transmission is completed. At this time, the energy accumulated in the ultrasonic sensor can be quickly released, which helps to reduce the aftershock time of the sensor and the voltage of the positive and negative drive ends is close after the energy is released, which helps to match the common mode voltage at both ends of the amplifier during subsequent reception.

[0059] In some embodiments, the direct drive circuit 4 further includes a first controllable switch tube, a second controllable switch tube, a third controllable switch tube, and a fourth controllable switch tube; the multi-channel control signal includes a first control signal, a second control signal, a third control signal, and a fourth control signal;

[0060] The control end of the first controllable switch tube receives a first control signal, the first end of the first controllable switch tube and the first end of the third controllable switch tube are both connected to the working voltage, and the second end of the first controllable switch tube and the second end of the second controllable switch tube are both connected to the positive driving end; the control end of the second controllable switch tube receives a second control signal, the first end of the second controllable switch tube and the first end of the fourth controllable switch tube are both grounded; the control end of the third controllable switch tube receives a third control signal, and the second end of the third controllable switch tube and the second end of the fourth controllable switch tube are both connected to the negative driving end; the control end of the fourth controllable switch tube receives a fourth control signal.

[0061] Specifically, in the present application, the gate of the first controllable switch tube receives the first control signal, the source of the first controllable switch tube and the source of the third controllable switch tube are connected to the working voltage, and the drain of the first controllable switch tube and the drain of the second controllable switch tube are connected to the positive drive end; the gate of the second controllable switch tube receives the second control signal, and the source of the second controllable switch tube and the source of the fourth controllable switch tube are grounded; the gate of the third controllable switch tube receives the third control signal, and the drain of the third controllable switch tube and the drain of the fourth controllable switch tube are connected to the negative drive end; the gate of the fourth controllable switch tube receives the fourth control signal.

[0062] Specifically, Figure 2 As shown, the direct drive circuit 4 in the present application adopts an H-bridge structure, including a first controllable switch tube M1, a second controllable switch tube M2, a third controllable switch tube M3 and a fourth controllable switch tube M4. The multi-channel control signal includes a first control signal, a second control signal, a third control signal and a fourth control signal; each controllable switch tube will be turned on after receiving the corresponding control signal, and different controllable switch tubes are turned on so that the direct drive circuit 4 enters different working modes.

[0063] In some embodiments, the first controllable switch tube and the third controllable switch tube are both P-type field effect tubes;

[0064] The second controllable switch tube and the fourth controllable switch tube are both N-type field effect tubes.

[0065] In some embodiments, Figure 3 As shown, the gate driving circuit includes a PMOS gate driving circuit 31 and an NMOS gate driving circuit 32; the input end of the PMOS gate driving circuit 31 and the input end of the NMOS gate driving circuit 32 are both connected to the output end of the control circuit, and the output end of the PMOS gate driving circuit and the output end of the NMOS gate driving circuit are both connected to the direct driving circuit;

[0066] The PMOS gate drive circuit 31 is used to turn on the P-type field effect transistor that needs to be turned on according to the working mode of the direct drive circuit;

[0067] The NMOS gate driving circuit 32 is used to turn on the N-type field effect transistor that needs to be turned on according to the working mode of the direct driving circuit.

[0068] It can be understood that the first controllable switch tube M1, the second controllable switch tube M2, the third controllable switch tube M3, and the fourth controllable switch tube M4 in the direct drive circuit 4 of the direct driver for ultrasonic sensors provided in the present application are relatively large in size. Therefore, when the control circuit 2 inputs the control signal into the direct drive circuit 4, it is necessary to use the gate drive circuit 3 to change the level of the control signal, thereby driving the control signal of the working mode corresponding to the direct drive circuit 4. Among them, the second controllable switch tube M2 and the fourth controllable switch tube M4 are N-type field effect tubes NMOS, and the gate drive is relatively simple, consisting of a multi-stage inverter connected in series; while the first controllable switch tube M1 and the third controllable switch tube M3 are P-type field effect tubes PMOS. Due to process limitations, the voltage Vgs must be limited to about -5V during driving, so the PMOS gate drive includes a gate voltage clamping circuit to limit the gate voltage of the PMOS when it is turned on to about the power supply voltage Vdd-5V instead of 0V. It can be understood that the gate drive circuit can adopt an existing gate drive circuit, and this application will not repeat it here.

[0069] As an example, Figure 4 As shown, the direct driver for an ultrasonic sensor provided by the present application, in the first working mode, receives the first multi-channel control signal output by the gate drive circuit, forms a first output path and outputs a positive voltage pulse, including:

[0070] The first controllable switch tube receives a first control signal and is turned on, the fourth controllable switch tube receives a fourth control signal and is turned on, the positive drive end is connected to the working voltage through the first controllable switch tube, and the negative drive end is grounded through the fourth controllable switch tube, so that the direct drive circuit 4 outputs a positive voltage pulse;

[0071] The direct drive circuit receives the second multi-path control signal output by the gate drive circuit in the second working mode, forms a second output path and outputs a negative voltage pulse, including:

[0072] The second controllable switch tube receives a second control signal and is turned on, the third controllable switch tube receives a third control signal and is turned on, the positive drive end is grounded through the second controllable switch tube, and the negative drive end is connected to the working voltage through the third controllable switch tube, so that the direct drive circuit 4 outputs a negative voltage pulse.

[0073] In some embodiments, when the direct drive circuit forms a third working mode, the first controllable switch tube, the second controllable switch tube, the third controllable switch tube and the fourth controllable switch tube are all turned off;

[0074] When the direct drive circuit forms a fourth working mode, the second controllable switch tube receives a second control signal and is turned on, and the fourth controllable switch tube receives a fourth control signal and is turned on.

[0075] Specifically, the direct drive circuit 4 needs to enter the first working mode. After the multiple control signals are input into the gate drive circuit 3, the PMOS gate drive circuit 31 increases the level of the first control signal, so that the first controllable switch tube M1 receives the first control signal and turns on, and the NMOS gate drive circuit 32 increases the level of the fourth control signal, so that the fourth controllable switch tube M4 receives the fourth control signal and turns on, and the positive drive end is connected to the working voltage through the first controllable switch tube M1, and the negative drive end is grounded through the fourth controllable switch tube M4. At this time, the direct drive circuit 4 forms the first working mode, and the positive drive end outputs a positive voltage pulse. When the direct drive circuit 4 needs to enter the first working mode, after the multiple control signals are input into the gate drive circuit, the NMOS gate drive circuit 32 increases the level of the second control signal, and the second controllable switch tube M2 receives the second control signal and turns on, and the PMOS gate drive circuit 31 increases the level of the third control signal, so that the third controllable switch tube M3 receives the third control signal and turns on, and the positive drive end is grounded through the second controllable switch tube M2, and the negative drive end is connected to the working voltage through the third controllable switch tube M3. At this time, the direct drive circuit 4 forms the second working mode, and the negative drive end outputs a negative voltage pulse.

[0076] In addition, in the present application, the H-bridge direct drive circuit 4 not only outputs positive and negative voltage pulses, but also briefly grounds both the positive drive end and the negative drive end after the emission is completed, so that the energy accumulated in the ultrasonic sensor can be quickly released. In addition to the first working mode and the second working mode, there are two other working modes, the third working mode is floating and the fourth working mode is grounded. When the direct drive circuit 4 needs to enter the third working mode, the PMOS gate drive circuit 31 and the NMOS gate drive circuit 32 do not increase the level of any controllable switch tube, so that the first controllable switch tube M1, the second controllable switch tube M2, the third controllable switch tube M3 and the fourth controllable switch tube M4 are all not turned on, and the positive and negative drive ends are completely suspended, which helps the ultrasonic sensor to resonate the piezoelectric piece after receiving the ultrasonic echo. When the direct drive circuit 4 needs to enter the fourth working mode, after the multiple control signals are input into the gate drive circuit, the NMOS gate drive circuit 32 increases the levels of the second control signal and the fourth control signal, so that the second controllable switch tube M2 receives the second control signal and turns on, and the fourth controllable switch tube M4 receives the fourth control signal and turns on. At this time, the positive drive end is grounded through the second controllable switch tube M2, and the negative drive end is grounded through the fourth controllable switch tube M4. At this time, the positive and negative outputs are briefly grounded after the transmission is completed. At this time, the energy accumulated in the ultrasonic sensor can be quickly released. Grounding is used to help reduce the aftershock time of the sensor and the voltages of the positive and negative drive ends are close after the residual amount is released, which helps to match the common-mode voltages at both ends of the amplifier during subsequent reception.

[0077] In some embodiments, the control circuit 2 comprises:

[0078] A controller and a two-phase non-overlapping clock, wherein the controller is connected to the two-phase non-overlapping clock;

[0079] The two-phase non-overlapping clock is used to insert a dead time when the controller switches the voltage pulses in the positive and negative directions.

[0080] The controller includes a plurality of pins, and a plurality of the plurality of pins are used to send multi-channel control signals to the direct drive circuit 4 .

[0081] The control circuit 2 provided in the present application includes a controller and a two-phase non-overlapping clock. It can be understood that the control circuit 2 in the present application includes at least four pins connected to the direct drive circuit 4, wherein the four pins are respectively connected to the gates of the first controllable switch tube M1, the second controllable switch tube M2, the third controllable switch tube M3, and the fourth controllable switch tube M4, so that the control circuit 2 inputs the multi-channel control signals sent into the corresponding gate drive circuit 3 through the corresponding pins, and drives the corresponding outputs of the multi-channel control signals, i.e., the first control signal, the second control signal, the third control signal, and the fourth control signal through the gate drive circuit 3, so that the direct drive circuit 4 receives different control signals, enters different working modes, and realizes the switching of positive and negative direction pulses. In addition, the controller also uses a two-phase non-overlapping clock inside, and a short dead time can be inserted in the switching of positive and negative direction pulses to prevent the two MOSFETs on the same side of the H-bridge from being turned on at the same time to generate a large current during switching.

[0082] The direct driver for ultrasonic sensors provided in the present application does not need to introduce negative pressure design, which reduces the design difficulty, substrate noise, and latchup risk. Compared with the design with negative pressure, the design is simplified and the chip area is reduced. Compared with the non-direct drive design, the cost of a peripheral intermediate circuit transformer is reduced, and the volume of the finished reversing radar is also reduced.

[0083] A second aspect of the embodiments of the present application provides a direct drive chip, which uses the direct driver for ultrasonic sensors described in any of the above embodiments.

[0084] It can be understood that the device embodiment provided above corresponds to the equipment embodiment described above, and the corresponding specific contents can be referenced to each other and will not be repeated here.

[0085] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0086] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0087] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction method, which is implemented in the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0088] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0089] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0090] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0091] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A direct driver for an ultrasonic sensor, characterized in that: The direct driver comprises: a level conversion circuit, a control circuit, a gate drive circuit and a direct drive circuit connected in sequence; The level conversion circuit is used to output a logic control signal that conforms to the working voltage of the direct driver when receiving a low voltage logic control signal; The control circuit is used to convert the received logic control signal into a multi-channel control signal; The gate drive circuit is used to switch and output a corresponding control signal according to the working mode of the direct drive circuit; The direct drive circuit is used to form a corresponding output path according to the received control signal, so that the direct drive circuit outputs positive and negative alternating voltage pulses to drive the ultrasonic sensor; Among them, when the direct drive circuit is in the first working mode, it receives the first multiple control signals output by the gate drive circuit, forms a first output path and outputs a positive voltage pulse; when the direct drive circuit is in the second working mode, it receives the second multiple control signals output by the gate drive circuit, forms a second output path and outputs a negative voltage pulse.

2. The direct driver for ultrasonic sensor according to claim 1, characterized in that: The direct drive circuit includes a positive drive terminal and a negative drive terminal; When the direct drive circuit forms a third output path according to the received multi-path control signals so that the direct drive circuit forms a third working mode, the positive drive terminal and the negative drive terminal of the direct drive circuit are both floating; When the direct drive circuit forms a fourth output path according to the received multi-path control signals so that the direct drive circuit forms a fourth operation mode, the positive drive terminal and the negative drive terminal of the direct drive circuit are both grounded.

3. The direct driver for ultrasonic sensor according to claim 2, characterized in that: The direct drive circuit further includes a first controllable switch tube, a second controllable switch tube, a third controllable switch tube, and a fourth controllable switch tube; the multi-channel control signal includes a first control signal, a second control signal, a third control signal, and a fourth control signal; The control end of the first controllable switch tube receives a first control signal, the first end of the first controllable switch tube and the first end of the third controllable switch tube are both connected to the working voltage, and the second end of the first controllable switch tube and the second end of the second controllable switch tube are both connected to the positive driving end; the control end of the second controllable switch tube receives a second control signal, the first end of the second controllable switch tube and the first end of the fourth controllable switch tube are both grounded; the control end of the third controllable switch tube receives a third control signal, and the second end of the third controllable switch tube and the second end of the fourth controllable switch tube are both connected to the negative driving end; the control end of the fourth controllable switch tube receives a fourth control signal.

4. The direct driver for ultrasonic sensor according to claim 3, characterized in that: The first controllable switch tube and the third controllable switch tube are both P-type field effect tubes; The second controllable switch tube and the fourth controllable switch tube are both N-type field effect tubes.

5. The direct driver for ultrasonic sensor according to claim 4, characterized in that: The gate drive circuit includes a PMOS gate drive circuit and an NMOS gate drive circuit; the input end of the PMOS gate drive circuit and the input end of the NMOS gate drive circuit are both connected to the output end of the control circuit, and the output end of the PMOS gate drive circuit and the output end of the NMOS gate drive circuit are both connected to the direct drive circuit; The PMOS gate drive circuit is used to turn on the P-type field effect transistor that needs to be turned on according to the working mode of the direct drive circuit; The NMOS gate drive circuit is used to turn on the N-type field effect transistor that needs to be turned on according to the working mode of the direct drive circuit.

6. The direct driver for ultrasonic sensor according to claim 3, characterized in that: The direct drive circuit receives the first multi-path control signal output by the gate drive circuit in the first working mode, forms a first output path and outputs a positive voltage pulse, including: The first controllable switch tube receives a first control signal and is turned on, the fourth controllable switch tube receives a fourth control signal and is turned on, the positive drive end is connected to the working voltage through the first controllable switch tube, and the negative drive end is grounded through the fourth controllable switch tube, so that the direct drive circuit outputs a positive voltage pulse; The direct drive circuit receives the second multi-path control signal output by the gate drive circuit in the second working mode, forms a second output path and outputs a negative voltage pulse, including: The second controllable switch tube receives a second control signal and is turned on, the third controllable switch tube receives a third control signal and is turned on, the positive drive end is grounded through the second controllable switch tube, and the negative drive end is connected to the working voltage through the third controllable switch tube, so that the direct drive circuit outputs a negative voltage pulse.

7. The direct driver for ultrasonic sensor according to claim 3, characterized in that: When the direct drive circuit forms a third working mode, the first controllable switch tube, the second controllable switch tube, the third controllable switch tube and the fourth controllable switch tube are all turned off; When the direct drive circuit forms a fourth working mode, the second controllable switch tube receives a second control signal and is turned on, and the fourth controllable switch tube receives a fourth control signal and is turned on.

8. The direct driver for ultrasonic sensor according to claim 1, characterized in that: The control circuit comprises: A controller and a two-phase non-overlapping clock, wherein the controller is connected to the two-phase non-overlapping clock; The two-phase non-overlapping clock is used to insert a dead time when the controller switches the voltage pulses in the positive and negative directions.

9. The direct driver for ultrasonic sensor according to claim 8, characterized in that: The controller includes a plurality of pins, and a plurality of the plurality of pins are used to send multiple control signals to the direct drive circuit.

10. The direct driver for ultrasonic sensor according to claim 1, characterized in that: The direct drive circuit adopts an H-bridge structure.

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