Hardware reset circuit

Abstract

The utility model provides a hardware reset circuit. The hardware reset circuit comprises a first diode, a first capacitor, a second diode and a first resistor, the anode of the first diode is connected with a first power supply end, the cathode of the first diode is connected with the first end of the first capacitor, the second end of the first capacitor is connected with the anode of the second diode, and the cathode of the second diode is connected with the first resistor. The cathode of the second diode is connected with the second power supply end, and the first end of the first capacitor is connected to the reset end of the controller. The reliability of the reset circuit can be improved.

Description

Technical Field

[0001] The present disclosure relates to the field of circuit technologies, and in particular, to a hardware reset circuit. Background Art

[0002] In an electronic circuit system, if a controller experiences situations such as crashing, deadlocking, or program runaway, the controller can be forced to restart through a reset circuit to resume normal operation. Currently, the commonly used reset method is mainly software reset through a watchdog. This method is simple to implement, but there may be a problem that the reset cannot be triggered, and the reliability is not high. Summary of the Utility Model

[0003] Embodiments of the present disclosure provide a hardware reset circuit to solve the problem of poor reliability of traditional reset circuits.

[0004] Embodiments of the present disclosure provide a hardware reset circuit, including a first diode, a first capacitor, a second diode, and a first resistor.

[0005] The anode of the first diode is connected to a first power supply terminal, the cathode of the first diode is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the anode of the second diode, the cathode of the second diode is connected to a second power supply terminal, the first end of the first capacitor is connected to the reset terminal of the controller, and the first power supply terminal and the second power supply terminal are configured to be connected to the power supply output terminal in a positive or reverse connection.

[0006] In an exemplary embodiment of the present disclosure, the first power supply terminal and the second power supply terminal are connected to the power supply output terminal through a first connection line, and a connection terminal is provided at one end of the first connection line. The connection terminal is used to switch the connection relationship between the first power supply terminal, the second power supply terminal, and the power supply output terminal to achieve the polarity switching of the first power supply terminal and the second power supply terminal.

[0007] In an exemplary embodiment of the present disclosure, the first connection line is a charging line, and the connection terminal is a charging port.

[0008] In an exemplary embodiment of the present disclosure, the first power supply terminal and the second power supply terminal are used to supply power to a charging circuit, and the hardware reset circuit further includes an anti-reverse connection protection circuit. The anti-reverse connection protection circuit includes a first switch and a second resistor.

[0009] The control end of the first switch is connected to the first power supply terminal through the second resistor, the first end of the first switch is connected to the second power supply terminal, and the second end of the first switch is connected to the charging circuit.

[0010] In an exemplary embodiment of the present disclosure, the first switch includes a second switching tube and a third switching tube.

[0011] The control terminal of the second switching tube is connected to the control terminal of the third switching tube, the second terminal of the second switching tube is connected to the first terminal of the third switching tube, the control terminal of the second switching tube is the control terminal of the first switch, the first terminal of the second switching tube is the first terminal of the first switch, and the second terminal of the third switching tube is the second terminal of the first switch.

[0012] In an exemplary embodiment of the present disclosure, a fourth resistor is provided between the first terminal and the control terminal of the second switching tube.

[0013] In an exemplary embodiment of the present disclosure, the control terminal of the first switch is connected to the first signal output terminal of the controller through a third resistor, and the controller is configured to:

[0014] When the communication circuit is working, control the first signal output terminal to output a control signal to control the first switch to turn off.

[0015] In an exemplary embodiment of the present disclosure, a second capacitor is provided between the second terminal of the first switch and the first power supply terminal. [[ID=A]]

[0016] In an exemplary embodiment of the present disclosure, a bidirectional voltage regulator tube is provided between the first power supply terminal and the second power supply terminal.

[0017] In an exemplary embodiment of the present disclosure, a third capacitor is provided between the reset terminal of the controller and the first power supply terminal.

[0018] The working principle and beneficial effects of the hardware reset circuit provided by the embodiments of the present disclosure are as follows:

[0019] In the embodiments of the present disclosure, the hardware reset circuit is applied to the first device. When the first device is working normally, the first power supply terminal is connected to the negative pole of the power supply (for example, grounded), and the second power supply terminal is connected to the positive pole of the power supply. Due to the reverse cut-off effect of the second diode, the reset terminal of the controller is not affected by the voltage of the power supply output terminal.

[0020] When the first device malfunctions, the first power supply terminal can be connected to the positive pole of the power supply, and the second power supply terminal is grounded. At this time, the first power supply terminal, the first diode, the first capacitor, and the second diode form a charging circuit. The first power supply terminal charges the first capacitor, and the voltage of the first capacitor rises. When the voltage of the first capacitor is greater than the set threshold, the reset terminal of the controller receives a high-level signal. Then, the connection between the first power supply terminal and the power supply output terminal is disconnected, and the first capacitor, the internal reset circuit of the controller, and the first resistor form a discharge circuit. The first capacitor discharges through the internal reset circuit of the controller and the first resistor, and the voltage of the first capacitor drops. When the voltage of the first capacitor is less than the set threshold, the reset terminal of the controller jumps to a low-level signal. Therefore, when the first device malfunctions, by switching the connection relationship between the first power supply terminal, the second power supply terminal, and the power supply output terminal, that is, by reversing the connection of the first power supply terminal, the second power supply terminal, and the power supply output terminal, a high-level reset pulse can be obtained at the reset terminal of the controller, realizing reliable reset of the controller. Brief Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 is the schematic diagram of the hardware reset circuit provided by the embodiment of the present disclosure;

[0023] Figure 2 is the schematic diagram of the reverse connection protection circuit provided by the embodiment of the present disclosure. Detailed Embodiments

[0024] In order to enable those skilled in the art to better understand this solution, the following will clearly describe the technical solutions in the embodiments of this solution in conjunction with the drawings in the embodiments of this solution. Obviously, the described embodiments are some, but not all, of the embodiments of this solution. Based on the embodiments in this solution, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this solution.

[0025] The term "including" in the specification, claims, and the above drawings of this solution, as well as any other variations, means "including but not limited to", intending to cover non-exclusive inclusion and not limited to the examples listed in the text. In addition, terms such as "first" and "second" are used to distinguish different objects, rather than to describe a specific order.

[0026] The following will describe the implementation of the present disclosure in detail with reference to the specific drawings:

[0027] Figure 1 This is a schematic diagram of a hardware reset circuit provided by an embodiment of the present disclosure. Refer to Figure 1 , the hardware reset circuit includes a first diode, a first capacitor, a second diode, and a first resistor.

[0028] The anode of the first diode is connected to the first power supply terminal, the cathode of the first diode is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the anode of the second diode, the cathode of the second diode is connected to the second power supply terminal, the first end of the first capacitor is connected to the reset terminal of the controller, and the first power supply terminal and the second power supply terminal are configured to be connected to the positive or negative terminal of the power supply output in a forward or reverse manner.

[0029] In an embodiment of the present disclosure, the hardware reset circuit is applied to a first device, and the first device may be any electronic device including a controller, such as smart glasses, smart watches, smart phones, motor controllers, smart sensors, etc. Among them, the controller may be a microcontroller such as a single-chip microcomputer, DSP, or ARM. The controller is equivalent to the "brain" of the first device and controls the orderly operation of other circuits in the first device.

[0030] When the first device is working properly, the first power supply terminal GND is connected to the negative terminal of the power supply (e.g., grounded), and the second power supply terminal VBUS_IN is connected to the positive terminal of the power supply (e.g., 5V). Due to the reverse cut-off effect of the second diode D7021, the reset terminal RESET of the controller is not affected by the voltage of the power supply output terminal.

[0031] When abnormal situations such as the controller crashing, deadlocking, or the program running wild occur, it will cause the first device to malfunction. At this time, the first power supply terminal GND can be connected to the positive pole of the power supply, and the second power supply terminal VBUS_IN can be grounded. At this time, the first power supply terminal GND, the first diode D7022, the first capacitor C7003, and the second diode D7021 form a charging circuit. The first power supply terminal GND charges the first capacitor C7003, and the voltage of the first capacitor C7003 increases. When the voltage of the first capacitor C7003 is greater than the set threshold, the reset terminal RESET of the controller receives a high-level signal. Then, the connection between the first power supply terminal GND and the positive pole of the power supply is disconnected. The first capacitor C7003, the internal reset circuit of the controller, and the first resistor R7006 form a discharge circuit. The first capacitor C7003 discharges through the internal reset circuit of the controller and the first resistor, and the voltage of the first capacitor C7003 decreases. When the voltage of the first capacitor C7003 is less than the set threshold, the reset terminal RESET of the controller jumps to a low-level signal. Therefore, when the first device malfunctions, by switching the connection relationship between the first power supply terminal GND, the second power supply terminal VBUS_IN, and the power supply output terminal, that is, by reversing the connection of the first power supply terminal GND and the second power supply terminal VBUS_IN to the two output terminals of the power supply, a high-level reset pulse can be obtained at the reset terminal of the controller to reliably reset the controller. After reset, the controller can resume normal operation, and the first device starts to work normally.

[0032] Existing reset methods also include: sending a specific pattern command through an external tool for resetting. This method requires additional external hardware design and is relatively expensive; in the traditional method, a reset button or a reset hole is added to the device, which will affect the appearance of the device.

[0033] Compared with the above two reset methods, the reset circuit of this embodiment does not require additional external hardware design, does not increase the cost of the first device, and does not require reserved mechanical switches, buttons, etc. designs, thus avoiding drilling holes on the first device.

[0034] In an exemplary embodiment of the present disclosure, the first power supply terminal and the second power supply terminal are connected to the power supply output terminal through a first connection line. One end of the first connection line is provided with a connection terminal, and the connection terminal is used to switch the connection relationship between the first power supply terminal, the second power supply terminal, and the power supply output terminal to achieve the polarity switching of the first power supply terminal and the second power supply terminal.

[0035] In this embodiment, the first power supply terminal and the second power supply terminal can be connected to the power supply output terminal through a first connection line. Among them, one end of the first connection line is provided with a connection terminal, and the connection terminal can be a magnetic or pluggable quick connection terminal to achieve the quick connection between the first power supply terminal, the second power supply terminal, and the power supply output terminal.

[0036] There are at least two connection points provided on the connection terminal. On the one hand, the two connection points are respectively connected to the positive electrode and the negative electrode of the power supply. For example, the first connection point is grounded and the second connection point is connected to the positive electrode of the power supply. On the other hand, the first connection point can be connected to the first power supply terminal and the second connection point can be connected to the second power supply terminal to achieve the correct connection between the first power supply terminal, the second power supply terminal and the two output terminals (positive electrode and negative electrode) of the power supply. It is also possible to connect the second connection point to the first power supply terminal and the first connection point to the second power supply terminal to achieve the reverse connection between the first power supply terminal, the second power supply terminal and the two ends of the power supply.

[0037] It can be concluded from the above that in this embodiment, the connection relationship between the first power supply terminal, the second power supply terminal and the power supply output terminal can be switched through the first connection line, and thus the polarity switching between the first power supply terminal and the second power supply terminal can be achieved.

[0038] In an exemplary embodiment of the present disclosure, the first connection line is a charging line and the connection terminal is a charging port.

[0039] In this embodiment, the first connection line can be a charging line, the connection terminal can be a charging port on the charging line, correspondingly, the first power supply terminal and the second power supply terminal can be charging ports on the first device. By correctly connecting or reversely connecting the charging line to the charging port of the first device, the connection relationship between the first power supply terminal, the second power supply terminal and the power supply output terminal can be switched, and thus the polarity switching between the first power supply terminal and the second power supply terminal can be achieved.

[0040] Taking the smart glasses as an example, both the charging line and the temple of the smart glasses have magnets. When aligning the magnet directions, during normal charging, if the charging line and the temple approach, they will be adsorbed together through the magnets for charging; when inserted reversely, the magnet polarities are the same and the two sides repel each other, and it is necessary to overcome the repulsive force of the magnets and force the reverse connection to achieve the reset of the controller.

[0041] This embodiment utilizes the existing charging ports and charging lines of the first device to achieve the polarity switching between the first power supply terminal and the second power supply terminal, further saving the device cost.

[0042] Refer to Figure 2 , in an exemplary embodiment of the present disclosure, the first power supply terminal and the second power supply terminal are used to supply power to the charging circuit, and the hardware reset circuit further includes an anti-reverse connection protection circuit. The anti-reverse connection protection circuit includes a first switch and a second resistor.

[0043] The control end of the first switch is connected to the first power supply terminal through the second resistor. The first end of the first switch is connected to the second power supply terminal, and the second end of the first switch is connected to the charging circuit.

[0044] In this embodiment, the first power supply terminal and the second power supply terminal are charging ports on the first device, and the battery inside the first device is charged through a charging circuit. The first switch can be implemented by a transistor, such as a triode, a MOS transistor, etc. The second resistor R7060 is a current-limiting resistor to prevent excessive current from flowing into the control terminal of the first switch.

[0045] When the charging port on the first device is connected to the positive power supply, the first power supply terminal is grounded, the second power supply terminal is connected to the positive power supply, the control terminal of the first switch is at a low level, and the first end and the second end of the first switch are conducting, connecting the charging circuit to the power supply, and normal charging can be carried out. When the charging port on the first device is reversely connected to the power supply, the first power supply terminal is connected to the positive power supply, the second power supply terminal is grounded, the control terminal of the first switch is at a high level, the first switch is turned off, disconnecting the connection between the charging circuit and the power supply, and preventing damage to the charging circuit caused by reverse connection of the power supply.

[0046] It can be concluded from the above that in this embodiment, by setting up an anti-reverse connection protection circuit, damage to the charging circuit caused by reverse connection of the charging port on the first device to the power supply can be avoided, further improving the reliability of the reset circuit.

[0047] In an exemplary embodiment of the present disclosure, the first switch includes a second switching tube and a third switching tube.

[0048] The control terminal of the second switching tube is connected to the control terminal of the third switching tube, the second end of the second switching tube is connected to the first end of the third switching tube, the control terminal of the second switching tube is the control terminal of the first switch, the first end of the second switching tube is the first end of the first switch, and the second end of the third switching tube is the second end of the first switch.

[0049] In this embodiment, the first switch is in the form of a combination of the second switching tube T7002 and the third switching tube T7000, which can improve the current-carrying capacity of the first switch and further improve the reliability of the first switch.

[0050] Specifically, both the first switching tube and the second switching tube are in the form of PMOS transistors. The control terminal of the first switching tube is the gate of the PMOS transistor, the first end of the first switching tube is the drain of the PMOS transistor, and the first end of the first switching tube is the source of the PMOS transistor. When a high-level signal is applied to the control terminals of the first switching tube and the second switching tube, the first switching tube and the second switching tube are turned off. When a low-level signal is applied to the control terminals of the first switching tube and the second switching tube, the first switching tube and the second switching tube are turned on.

[0051] In an exemplary embodiment of the present disclosure, a fourth resistor is provided between the first end and the control terminal of the second switching tube.

[0052] In this embodiment, external interference signals may cause the second switching transistor to be mis-triggered. By connecting a fourth resistor R7055 in parallel between the first end and the control end of the second switching transistor, a filtering effect can be achieved, reducing the impact of external interference signals on the control end of the second switching transistor, thereby improving the anti-interference ability of the second switching transistor and preventing mis-triggering.

[0053] In an exemplary embodiment of the present disclosure, the control end of the first switch is connected to the first signal output end of the controller through a third resistor, and the controller is configured to:

[0054] When the communication circuit is operating, control the first signal output end to output a control signal to control the first switch to turn off.

[0055] In this embodiment, when the first device performs low-voltage communication, a high-level control signal UART_COM_EN can be output through the first signal output end of the controller to actively control the disconnection of the first switch and prevent the charging circuit from affecting the transmission of communication signals. Among them, the third resistor R7064 is a current-limiting resistor to avoid excessive current flowing into the control end of the first switch.

[0056] In an exemplary embodiment of the present disclosure, a second capacitor is provided between the second end of the first switch and the first power supply end.

[0057] In this embodiment, the second capacitor C7056 plays a role in stabilizing the voltage, which is beneficial to providing a stable voltage input for the subsequent charging circuit.

[0058] In an exemplary embodiment of the present disclosure, a bidirectional voltage regulator tube is provided between the first power supply end and the second power supply end.

[0059] In this embodiment, when an excessive voltage pulse appears between the first power supply end and the second power supply end, the bidirectional voltage regulator tube D7018 will quickly conduct, clamping the voltage signal within a safe range, thereby preventing excessive voltage from damaging the components in the subsequent circuit.

[0060] In an exemplary embodiment of the present disclosure, a third capacitor is provided between the reset end of the controller and the first power supply end.

[0061] In this embodiment, the third capacitor C7003 plays a filtering role to avoid false reset of the controller caused by short-term power supply fluctuations or interference signals.

[0062] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A hardware reset circuit, characterized in that, It includes a first diode, a first capacitor, a second diode and a first resistor. The anode of the first diode is connected to a first power supply terminal, the cathode of the first diode is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the anode of the second diode, the cathode of the second diode is connected to a second power supply terminal, the first end of the first capacitor is connected to the reset terminal of the controller, and the first power supply terminal and the second power supply terminal are configured to be connected to the power output terminal in a forward or reverse manner.

2. The hardware reset circuit according to claim 1, wherein The first power supply terminal and the second power supply terminal are connected to the power output terminal through a first connection wire, and a connection terminal is provided at one end of the first connection wire. The connection terminal is used to switch the connection relationship between the first power supply terminal, the second power supply terminal and the power output terminal to realize the polarity switching of the first power supply terminal and the second power supply terminal.

3. The hardware reset circuit according to claim 2, characterized in that, The first connection wire is a charging wire, and the connection terminal is a charging port.

4. The hardware reset circuit according to claim 1, characterized in that The first power supply terminal and the second power supply terminal are used to supply power to the charging circuit. The hardware reset circuit further includes an anti-reverse connection protection circuit, and the anti-reverse connection protection circuit includes a first switch and a second resistor. The control end of the first switch is connected to the first power supply terminal through the second resistor, the first end of the first switch is connected to the second power supply terminal, and the second end of the first switch is connected to the charging circuit.

5. The hardware reset circuit according to claim 4, wherein The first switch includes a second switching tube and a third switching tube. The control end of the second switching tube is connected to the control end of the third switching tube, the second end of the second switching tube is connected to the first end of the third switching tube, the control end of the second switching tube is the control end of the first switch, the first end of the second switching tube is the first end of the first switch, and the second end of the third switching tube is the second end of the first switch.

6. The hardware reset circuit according to claim 5, wherein A fourth resistor is provided between the first end and the control end of the second switching tube.

7. The hardware reset circuit according to claim 4, characterized in that The control end of the first switch is connected to the first signal output end of the controller through a third resistor, and the controller is configured to: When the communication circuit is working, control the first signal output end to output a control signal to control the first switch to be cut off.

8. The hardware reset circuit according to claim 4, wherein, A second capacitor is provided between the second end of the first switch and the first power supply terminal.

9. The hardware reset circuit according to claim 1, wherein A bidirectional voltage stabilizing tube is provided between the first power supply terminal and the second power supply terminal.

10. The hardware reset circuit according to claim 1, characterized in that, A third capacitor is provided between the reset terminal of the controller and the first power supply terminal.

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