Drive signal emergency shutdown circuit

Abstract

The utility model relates to a kind of drive signal emergency shutdown circuit, including first switch module and second switch module: one end of the first switch module is connected drive signal, the other end of the first switch module is connected drive load;One end of the second switch module is connected the other end of the first switch module, the other end of the second switch module is grounded.The utility model can be realized in low-cost mode, the normal transmission and emergency shutdown of drive signal are completed by the high-low change of control signal, improve system security, so that the drive signal of critical load is controllable.

Description

Technical Field

[0001] This utility model relates to the field of signal logic processing technology, specifically to an emergency shutdown circuit for drive signals. Background Technology

[0002] With the rapid development of the automotive industry and the increasing electrification of vehicles, the safety of automotive functions has faced greater challenges. In development scenarios with high functional safety requirements for electrical equipment, it is essential to consider preventing unexpected negative behaviors when certain components fail or malfunction. For example, in a MOS-driven motor, the drive signal controls the motor's rotation by controlling the voltage between the gate and source of the MOS transistor. Typically, the drive signal is issued by a driver chip. If the driver chip fails, the drive signal becomes uncontrollable, causing the motor to rotate unexpectedly and negatively. In scenarios with high functional safety requirements, it is necessary to urgently shut down the drive signal in case of a fault. Current conventional drive signal shutdown relies on the high functional safety level of the driver chip itself, shutting down the output in case of a fault. However, shutting down a high functional safety level chip will shut down the entire chip, causing it to malfunction. Therefore, when it is necessary to shut down only the drive signal while preserving other chip functions, it is not possible to shut down the drive signal alone. Furthermore, functional safety level chips are expensive, increasing costs. Utility Model Content

[0003] To address the technical problem in existing technologies, such as the inability to independently shut down the drive signal, this utility model provides an emergency shutdown circuit for the drive signal.

[0004] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: An emergency shutdown circuit for a drive signal includes a first switch module and a second switch module: one end of the first switch module is connected to a drive signal, and the other end of the first switch module is connected to a drive load; one end of the second switch module is connected to the other end of the first switch module, and the other end of the second switch module is grounded.

[0005] The beneficial effects of this invention are as follows: By utilizing a first switch module to control the transmission channel of the drive signal to the drive load, an emergency shutdown of the drive signal can be achieved. Simultaneously, a second switch module controls the grounding channel at the other end of the first switch module. Since the other end of the first switch module is connected to the drive load, when the second switch module controls the grounding channel at the other end of the first switch module to be connected, even if the first switch module cannot be completely disconnected, the end of the first switch module connected to the drive load is grounded through the second switch module, causing the drive signal to fail, thus achieving an emergency shutdown of the drive signal. The circuit provided by this invention can be implemented in a low-cost manner, achieving normal transmission and emergency shutdown of the drive signal by controlling the high and low changes of the control signal, improving system safety, and making the drive signal of critical loads controllable.

[0006] Based on the above technical solution, the present invention can be further improved as follows: Furthermore, both the first switch module and the second switch module are electrically controlled switches.

[0007] Furthermore, it also includes a third switch module, which is an electronically controlled switch: one end of the third switch module is connected to the control terminal of the first switch module, the other end of the third switch module is grounded, and the control terminal of the third switch module is connected to a shutdown control signal.

[0008] Furthermore, it also includes a fourth switch module, which is an electronically controlled switch. One end of the fourth switch module is connected to the control terminal of the second switch module, and the other end of the fourth switch module is grounded. The control terminal of the fourth switch module is connected to the shutdown control signal, and one end of the fourth switch module is connected to the power supply voltage.

[0009] Furthermore, the first switching module is a PMOS transistor switching circuit module.

[0010] Furthermore, the PMOS transistor switching circuit module includes a first resistor, a second resistor, and a PMOS transistor. One end of the first resistor is connected to the source of the PMOS transistor, and the other end of the first resistor is connected to the gate of the PMOS transistor. One end of the second resistor is connected to the gate of the PMOS transistor, and the other end of the second resistor is connected to one end of the third switching module. The source of the PMOS transistor is connected to the drive signal, and the drain of the PMOS transistor is connected to the drive load.

[0011] Furthermore, the third switching module is a transistor switching circuit module, which includes a third resistor, a fourth resistor, and a first transistor. One end of the third resistor is connected to the shutdown control signal shutdown, and the other end of the third resistor is connected to the base of the first transistor. One end of the fourth resistor is connected to the base of the first transistor, the collector of the first transistor is connected to the other end of the second resistor, and the other end of the fourth resistor and the emitter of the first transistor are both grounded.

[0012] Furthermore, the fourth switching module is a transistor switching circuit module, which includes a fifth resistor, a sixth resistor, a seventh resistor, and a second transistor. One end of the fifth resistor is connected to one end of the third resistor, and the other end of the fifth resistor is connected to the base of the second transistor. One end of the seventh resistor is connected to a 5V power supply voltage, and the other end of the seventh resistor is connected to the collector of the second transistor. One end of the sixth resistor is connected to the base of the second transistor, and the other end of the sixth resistor and the emitter of the second transistor are both grounded. The collector of the second transistor is connected to the control terminal of the second switching module.

[0013] Furthermore, the second switching module is a transistor switching circuit module.

[0014] Furthermore, the second switching module includes an eighth resistor, a ninth resistor, a tenth resistor, and a third transistor; one end of the eighth resistor is connected to the base of the second transistor, one end of the tenth resistor is connected to the drain of the PMOS transistor, the other end of the tenth resistor is connected to the collector of the second transistor, one end of the ninth resistor is connected to the base of the second transistor, and the other end of the ninth resistor and the drain of the second transistor are both grounded. Attached Figure Description

[0015] Figure 1 This is a circuit diagram of an emergency shutdown circuit for a drive signal in an embodiment of this utility model; Figure 2 This is a circuit diagram of a load driving embodiment of the present invention; Figure 3 This is a simulation waveform diagram of the embodiment of the present invention without the second switch module connected; Figure 4 This is a simulation waveform diagram of an emergency shutdown circuit for a drive signal in an embodiment of this utility model.

[0016] The attached diagram lists the components represented by each number as follows: 1-First switch module, 2-Second switch module, 3-Third switch module, 4-Fourth switch module. Detailed Implementation

[0017] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0018] like Figure 1 As shown, this embodiment provides a drive signal emergency shutdown circuit, characterized in that it includes: The first switch module 1 has a drive signal connected to one end and a drive load connected to the other end, and is used to open or close the channel for transmitting the drive signal to the drive load. The second switch module 2 has one end connected to the other end of the first switch module 1 and the other end grounded, and is used to turn on or off the grounding channel of the other end of the first switch module 1.

[0019] In this embodiment, the first switch module 1 can be an electronically controlled switch, a programmable switch, a relay switch, or a general manual switch; the second switch module 2 can also be an electronically controlled switch, a programmable switch, a relay switch, or a general manual switch. That is, when the drive signal transmission channel needs to be opened, the first switch module 1 is directly closed; when the drive signal transmission channel needs to be closed, the first switch module 1 is directly opened. When the drive signal needs to be eliminated through grounding, the second switch module 2 is closed. The drive signal is eliminated after grounding. If the drive signal is a high-level voltage signal, after grounding, the high-level voltage signal is pulled low to become a low-level signal. If the drive signal is a pulse-width modulation (PWM) signal, when the second switch module 2 is closed, the PWM signal is pulled low to become a low-level signal, and similarly, the PWM signal cannot be transmitted normally to the drive load.

[0020] This embodiment of the invention utilizes a first switch module 1 to control the transmission channel of the drive signal to the drive load, thereby achieving an emergency shutdown of the drive signal. Simultaneously, a second switch module 2 controls the grounding channel at the other end of the first switch module 1. Since the other end of the first switch module 1 is connected to the drive load, when the second switch module 2 controls the grounding channel at the other end of the first switch module 1 to be connected, even if the first switch module 1 cannot be completely shut down, the end of the first switch module 1 connected to the drive load is grounded through the second switch module 2, causing the drive signal to fail, thus achieving an emergency shutdown of the drive signal. The circuit provided by this embodiment of the invention can be implemented in a low-cost manner, achieving normal transmission and emergency shutdown of the drive signal by controlling the high and low changes of the control signal, improving system safety, and making the drive signal of critical loads controllable.

[0021] In some embodiments, both the first switch module 1 and the second switch module 2 are electrically controlled switches. Specifically, the first switch module 1 is a PMOS transistor switching circuit module. By configuring both the first switch module 1 and the second switch module 2 as electrically controlled switches, the on / off state of the first switch module 1 and the second switch module 2 can be controlled by electrically controlling them.

[0022] The PMOS transistor switching circuit module includes a first resistor R1, a second resistor R2, and a PMOS transistor M1. One end of the first resistor R1 is connected to the source of the PMOS transistor M1, and the other end of the first resistor R1 is connected to the gate of the PMOS transistor M1. One end of the second resistor R2 is connected to the gate of the PMOS transistor M1, and the other end of the second resistor R2 is connected to one end of the third switching module 3. The source of the PMOS transistor M1 is connected to the drive signal, and the drain of the PMOS transistor M1 is connected to the drive load.

[0023] In some embodiments, the above-mentioned emergency shutdown circuit for the drive signal further includes a third switch module 3, which is an electronically controlled switch: one end of the third switch module 3 is connected to the control terminal of the first switch module 1, the other end of the third switch module 3 is grounded, and the control terminal of the third switch module 3 is connected to a shutdown control signal; the third switch module 3 is used to open or close the grounding channel of the control terminal of the first switch module 1 under the control of the shutdown control signal; when the grounding channel of the control terminal of the first switch module 1 is opened, the first switch module 1 opens the channel for transmitting the drive signal to the drive load; when the grounding channel of the control terminal of the first switch module 1 is closed, the first switch module 1 closes the channel for transmitting the drive signal to the drive load.

[0024] The third switch module 3 includes a third resistor R3, a fourth resistor R4, and a first transistor Q1. One end of the third resistor R3 is connected to the shutdown control signal shutdown, and the other end of the third resistor R3 is connected to the base of the first transistor Q1. One end of the fourth resistor R4 is connected to the base of the first transistor Q1. The collector of the first transistor Q1 is connected to the other end of the second resistor R2. The other end of the fourth resistor R4 and the emitter of the first transistor Q1 are both grounded.

[0025] In some embodiments, the above-mentioned drive signal emergency shutdown circuit further includes a fourth switch module 4, which is an electronically controlled switch. One end of the fourth switch module 4 is connected to the control terminal of the second switch module 2, and the other end of the fourth switch module 4 is grounded. The control terminal of the fourth switch module 4 is connected to the shutdown control signal, and one end of the fourth switch module 4 is connected to the power supply voltage. The fourth switch module 4 is used to open or close the grounding channel of the control terminal of the second switch module 2 under the control of the shutdown control signal; when the grounding channel of the control terminal of the second switch module 2 is opened, the grounding channel of the other end of the first switch module 1 is opened; when the grounding channel of the control terminal of the second switch module 2 is closed, the grounding channel of the other end of the first switch module 1 is closed.

[0026] The fourth switch module 4 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and a second transistor Q2. One end of the fifth resistor R5 is connected to one end of the third resistor R3, and the other end of the fifth resistor R5 is connected to the base of the second transistor Q2. One end of the seventh resistor R7 is connected to a 5V power supply voltage, and the other end of the seventh resistor R7 is connected to the collector of the second transistor Q2. One end of the sixth resistor R6 is connected to the base of the second transistor Q2, and the other end of the sixth resistor R6 and the emitter of the second transistor Q2 are both grounded. The collector of the second transistor Q2 is connected to the control terminal of the second switch module 2.

[0027] By configuring both the third switch module 3 and the fourth switch module 4 as transistor switch circuit modules, the switching on and off of the third switch module 3 and the fourth switch module 4 can be controlled using a low-voltage shutdown control signal.

[0028] In some embodiments, the second switching module 2 is a transistor switching circuit module. The second switching module 2 includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, and a third transistor Q3; one end of the eighth resistor R8 is connected to the base of the second transistor Q2, one end of the tenth resistor R10 is connected to the drain of the PMOS transistor M1, the other end of the tenth resistor R10 is connected to the collector of the second transistor Q2, one end of the ninth resistor R9 is connected to the base of the second transistor Q2, and the other end of the ninth resistor R9 and the drain of the second transistor Q2 are both grounded.

[0029] In some other embodiments, the operating principle of the above-mentioned drive signal emergency shutdown circuit is as follows: The first switch module 1 is used to open or close the channel through which the drive signal is transmitted to the drive load; The grounding channel at the other end of the first switch module 1 is turned on or off using the second switch module 2; wherein, one end of the first switch module 1 is connected to the drive signal, and the other end of the first switch module 1 is connected to the drive load.

[0030] drv_in is the input signal of the drive signal, drv_out is the output signal of the controlled drive signal after passing through the first switch module 1, and shutdown is the shutdown control signal. The shutdown control signal is the control signal for normal transmission of the drive signal or emergency shutdown. The 5V power supply voltage is a pull-up high level.

[0031] The implementation principle is as follows: When normal transmission of the drive signal is required, the shutdown control signal is set to high, turning on the first transistor Q1 and pulling the gate of PMOS transistor M1 low, thus turning on PMOS transistor M1 and allowing the drv signal to pass through M1 normally. When the shutdown signal is high, the second transistor Q2 is turned on, and the base of the third transistor Q3 is pulled low, turning off the third transistor Q3. The drv_out signal is unaffected, and the drive signal is transmitted normally to the driven end, i.e., the drive load end.

[0032] When an emergency shutdown of the drive signal is required, the shut_down signal is set to low. The first transistor Q1 is off. The PMOS transistor M1, theoretically, should be turned off because the gate and source are connected by the first resistor R1. However, due to the parasitic parameters of PMOS transistor M1, it cannot be completely turned off in practice. When the shut_down signal is low, the second transistor Q2 is off. The base of the third transistor Q3 is pulled high by the seventh resistor R7 and the 5V high level, turning on Q3. Consequently, drv_out is pulled down to ground, and the drive signal is completely shut off.

[0033] To verify the effectiveness of the circuit, simulation results were used for verification. Two simulation circuits were compared: like Figure 2 As shown, the first type of drive load simulates a motor or coil-type load driven by the high side of an NMOS transistor; the drive signal drv_in simulates a 0~24V high-low transition signal with a frequency of 10kHz and a duty cycle of 50%; the shutdown signal simulates the control drive signal alternating between 1ms normal transmission and 1ms emergency shutdown; the power supply for the drive load is 13.5V, and the change in the load signal level can be used to indicate whether the drive signal is being transmitted normally or shut down in an emergency.

[0034] like Figure 3As shown, when the circuit without the second switch module is turned off, if the shutdown signal is high, the system should transmit the drive signal normally. In the figure, the load1 signal and the drv_in drive signal change high and low at the same frequency, indicating that the drive signal is transmitted normally to the load end, and the NMOS transistor M2 in the load switches normally. If the shutdown signal is low, the system should shut down the drive signal urgently. However, in the figure, the load signal and the drv_in drive signal are still changing high and low at the same frequency, and the level is relatively high, indicating that the drive signal is still driving the load and cannot achieve emergency shutdown.

[0035] like Figure 4 As shown, when the circuit provided by this utility model is used to turn off the drive signal, when the shutdown signal is high, the system should transmit the drive signal normally. In the figure, the load signal and the drv_in drive signal change high and low at the same frequency, indicating that the drive signal has been transmitted normally to the load end, and the NMOS transistor in the load is switching normally. When the shutdown signal is low, the system should shut down the drive signal urgently. The load signal becomes approximately low, indicating that the drive signal has been shut down urgently (the phenomenon of load glitches during shutdown can be optimized by adjusting the circuit parameters. In actual engineering applications, the load is completely shut down).

[0036] Comparing the two simulation results shows that the emergency shutdown circuit needs a pull-down section circuit, i.e., a second switching module, to achieve normal shutdown. Simply using the PMOS transistor to turn it off cannot achieve complete shutdown.

[0037] Existing technologies typically use NMOS transistors, but NMOS transistors require high drive voltages, increasing the complexity of the circuit's power supply voltage. This invention uses a PMOS transistor whose output terminal (drain D has residual electromotive force or residual voltage to ground) after being turned off. This residual voltage may have driving capability for some circuits or chips with low drive voltage requirements, resulting in the inability to turn off the drive signal in time. By using a transistor or MOS transistor switch for grounding, the voltage value (residual electromotive force or residual voltage to ground) can be weakened in time, thereby reducing its driving capability and achieving the function of timely cutting off the drive signal.

[0038] In other embodiments, this invention can be applied to a motor drive signal shutdown control device or equipment for automobiles to achieve emergency shutdown of the drive signal.

[0039] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the concept and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An emergency shutdown circuit for a drive signal, characterized in that, It includes a first switch module (1) and a second switch module (2); One end of the first switch module (1) is connected to a drive signal, and the other end of the first switch module (1) is connected to a drive load; One end of the second switch module (2) is connected to the other end of the first switch module (1), and the other end of the second switch module (2) is grounded; both the first switch module (1) and the second switch module (2) are electronically controlled switches; It also includes a third switch module (3), which is an electronically controlled switch: one end of the third switch module (3) is connected to the control terminal of the first switch module (1), the other end of the third switch module (3) is grounded, and the control terminal of the third switch module (3) is connected to a shutdown control signal; It also includes a fourth switch module (4), which is an electronically controlled switch. One end of the fourth switch module (4) is connected to the control terminal of the second switch module (2), and the other end of the fourth switch module (4) is grounded. The control terminal of the fourth switch module (4) is connected to the shutdown control signal, and one end of the fourth switch module (4) is connected to the power supply voltage.

2. The emergency shutdown circuit for the drive signal according to claim 1, characterized in that, The first switching module (1) is a PMOS transistor switching circuit module.

3. The emergency shutdown circuit for the drive signal according to claim 2, characterized in that, The PMOS transistor switching circuit module includes a first resistor (R1), a second resistor (R2), and a PMOS transistor (M1). One end of the first resistor (R1) is connected to the source of the PMOS transistor (M1), and the other end of the first resistor (R1) is connected to the gate of the PMOS transistor (M1). One end of the second resistor (R2) is connected to the gate of the PMOS transistor (M1), and the other end of the second resistor (R2) is connected to one end of the third switching module (3). The source of the PMOS transistor (M1) is connected to the drive signal, and the drain of the PMOS transistor (M1) is connected to the drive load.

4. The emergency shutdown circuit for the drive signal according to claim 3, characterized in that, The third switch module (3) is a transistor switch circuit module. The third switch module (3) includes a third resistor (R3), a fourth resistor (R4), and a first transistor (Q1). One end of the third resistor (R3) is connected to the shutdown control signal shutdown, and the other end of the third resistor (R3) is connected to the base of the first transistor (Q1). One end of the fourth resistor (R4) is connected to the base of the first transistor (Q1). The collector of the first transistor (Q1) is connected to the other end of the second resistor (R2). The other end of the fourth resistor (R4) and the emitter of the first transistor (Q1) are both grounded.

5. The emergency shutdown circuit for the drive signal according to claim 4, characterized in that, The fourth switch module (4) is a transistor switch circuit module. The fourth switch module (4) includes a fifth resistor (R5), a sixth resistor (R6), a seventh resistor (R7), and a second transistor (Q2). One end of the fifth resistor (R5) is connected to one end of the third resistor (R3), and the other end of the fifth resistor (R5) is connected to the base of the second transistor (Q2). One end of the seventh resistor (R7) is connected to a 5V power supply voltage, and the other end of the seventh resistor (R7) is connected to the collector of the second transistor (Q2). One end of the sixth resistor (R6) is connected to the base of the second transistor (Q2), and the other end of the sixth resistor (R6) and the emitter of the second transistor (Q2) are both grounded. The collector of the second transistor (Q2) is connected to the control terminal of the second switch module (2).

6. The emergency shutdown circuit for the drive signal according to claim 5, characterized in that, The second switching module (2) is a transistor switching circuit module.

7. The emergency shutdown circuit for the drive signal according to claim 6, characterized in that, The second switching module (2) includes an eighth resistor (R8), a ninth resistor (R9), a tenth resistor (R10), and a third transistor (Q3); one end of the eighth resistor (R8) is connected to the base of the second transistor (Q2), one end of the tenth resistor (R10) is connected to the drain of the PMOS transistor (M1), the other end of the tenth resistor (R10) is connected to the collector of the second transistor (Q2), one end of the ninth resistor (R9) is connected to the base of the second transistor (Q2), and the other end of the ninth resistor (R9) and the drain of the second transistor (Q2) are both grounded.

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