A protection circuit and chip

Abstract

The application discloses a protection circuit and a chip, the protection circuit comprises a switching power supply circuit and a comparison module, the switching power supply circuit comprises a control module, a switching tube and a power ground, the comparison module is connected with the power ground, the comparison module is connected with the control module, and the control module is connected with the switching tube. The application realizes monitoring voltage fluctuation of the power ground based on the comparison module and outputs a corresponding protection signal to the control module, so that the control module adjusts the output signal according to the received protection signal, reduces the influence of excessive fluctuation of the power ground on the sensitive signal, and improves the stability and safety of the system circuit.

Description

Technical Field

[0001] This invention relates to the field of circuit design, and more specifically to a protection circuit and chip. Background Technology

[0002] In the process of circuit design, in order to prevent interference between various circuits during operation and to ensure that various circuits can work in a compatible and effective manner, the "zero potential" (ground) in the circuit is usually divided into different types according to the nature of the circuit. For example, according to AC / DC, it can be divided into DC ground and AC ground; according to the type of reference signal, it can be divided into digital ground (logic ground) and analog ground; and according to power, it can be divided into signal ground, power ground and power supply ground, etc.

[0003] Digital ground, signal ground, and analog ground are reference grounds for system circuits. They require high ground stability and are easily affected by power ground interference, which can impact the performance of critical digital and / or analog signals. Therefore, to prevent power ground from interfering with other circuits, it is usually wired independently to ensure the stable operation of the entire system. However, independent wiring of power ground can lead to excessive voltage fluctuations, causing a cascading effect and also affecting the performance of sensitive signals. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a protection circuit and chip. By incorporating a comparison module, it monitors fluctuations in the power ground and outputs corresponding protection signals based on these fluctuations to adjust the circuit. This reduces the impact of excessive power ground fluctuations on sensitive signals, thereby improving the stability and security of the system circuit. The specific technical solution of this invention is as follows:

[0005] A protection circuit includes a switching power supply circuit and a comparator module. The switching power supply circuit includes a control module, a switching transistor, and a power ground. The switching transistor is connected to the power ground. The comparator module is connected to the power ground and is used to compare voltage fluctuations of the power ground to output a protection signal. The switching transistor is connected to the control module. The comparator module is also connected to the control module to transmit the protection signal output by the comparator module to the control module. The control module adjusts the pulse frequency of its output PWM signal according to the protection signal.

[0006] Further, the comparison module specifically includes: a comparator and a reference voltage module; wherein, the inverting input terminal of the comparator is connected to the power ground for acquiring the voltage fluctuation of the power ground; the non-inverting input terminal of the comparator is connected to the reference voltage module for enabling the comparator to acquire a reference voltage for comparison with the voltage fluctuation of the power ground; the output terminal of the comparator is connected to the control module for transmitting a protection signal output according to the voltage fluctuation of the power ground to the control module.

[0007] Furthermore, the reference voltage module includes: a first capacitor, a first resistor, and a second resistor; wherein, one end of the first capacitor is connected to the non-inverting input of the comparator, and the other end of the first capacitor is connected to the power supply ground; one end of the first resistor is connected to the non-inverting input of the comparator, and the other end of the first resistor is connected to the power supply; one end of the second resistor is connected to the non-inverting input of the comparator, and the other end of the second resistor is connected to the power supply ground.

[0008] Furthermore, the comparison module also includes a third resistor as a pull-up resistor; wherein one end of the third resistor is connected to the output terminal of the comparator, and the other end of the third resistor is connected to the power supply.

[0009] Furthermore, the switching power supply circuit also includes: a supercapacitor, an RCD snubber circuit, a transformer, and a fourth resistor; wherein, one end of the supercapacitor is connected to the power supply ground, the other end of the supercapacitor is connected to one end of the RCD snubber circuit, the other end of the RCD snubber circuit is connected to one end of the transformer, the other end of the transformer is connected to one end of the switching transistor, the other end of the switching transistor is connected to one end of the fourth resistor, and the other end of the fourth resistor is connected to the output terminal of the control module.

[0010] Furthermore, the RCD absorption circuit specifically includes: a fifth resistor, a second capacitor, and a diode; wherein, the second capacitor is connected in parallel with the fifth resistor, one end of the second capacitor connected in parallel with the fifth resistor is connected to the other end of the supercapacitor, the other end of the second capacitor connected in parallel with the fifth resistor is connected to the negative terminal of the diode, and the positive terminal of the diode is connected to one end of the transformer.

[0011] Furthermore, the power ground is short-circuited with the power supply ground; wherein, the power ground and the power supply ground are connected through a sixth resistor with a resistance of 0, or through a ferrite bead, or directly.

[0012] Furthermore, the switching transistor is an NMOS transistor; wherein, the gate of the NMOS transistor is connected to one end of the fourth resistor, the gate of the NMOS transistor is connected to the other end of the transformer, and the source of the NMOS transistor is connected to the power ground.

[0013] Furthermore, the control module includes a microcontroller unit, and the protection signal is input to the microcontroller unit by the comparison module; after receiving the protection signal, the microcontroller unit adjusts the pulse frequency of its output PWM signal.

[0014] The present invention also discloses a chip, wherein the chip includes the protection circuit described in any of the preceding claims.

[0015] The beneficial effects of this invention are as follows: the voltage fluctuation of the power ground is monitored by the comparison module, and the voltage of the power ground is compared with the reference voltage to determine whether the voltage fluctuation of the power ground is too large. This controls the output of the protection signal of the comparison module, and the protection signal modulates the output signal of the control module, thereby indirectly regulating the fluctuation of the power ground, reducing the impact of excessive power ground fluctuation on sensitive signals, and improving the stability and safety of the overall circuit. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the protection circuit according to one embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of the protection circuit according to another embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram of the protection circuit according to another embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described below are merely illustrative of the invention and are not intended to limit the invention. Furthermore, it should be understood that for those skilled in the art, making design, manufacturing, or production modifications to the technical content disclosed in this invention is merely a conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0020] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "comprising," "including," "having," and any variations thereof used in this application are intended to cover a non-exclusive inclusion, such as: a process, method, system product, or apparatus that comprises a series of steps or modules, not limited to the listed steps or modules, but may also include steps or modules not listed, or may also include other steps or modules inherent to these processes, methods, products, or apparatuses.

[0021] While many current system circuits design independently wire the "zero potential" (ground), the power ground still experiences significant fluctuations during operation. This application proposes a protection circuit to provide a protective signal response to power ground fluctuations, preventing excessive fluctuations from affecting the performance of sensitive signals and causing a chain reaction of adverse effects, thereby effectively improving the safety and stability of the system circuit.

[0022] As a preferred embodiment of the present invention, the first embodiment of the present invention provides a protection circuit, which includes a switching power supply circuit and a comparison module; wherein the switching power supply circuit includes at least: a control module, a switching transistor Q and a power ground.

[0023] Specifically, such as Figure 1 As shown, the switching transistor Q is connected to the power ground; the comparison module is connected to the power ground and is used to monitor and compare the voltage fluctuations of the power ground, and output a corresponding protection signal; the comparison module is connected to the control module and is used to transmit the protection signal to the control module, so that the control module adjusts its output signal according to the received protection signal, so as to achieve the purpose of adaptive parameter adjustment of the protection circuit in the case of excessive power ground fluctuation, and prevent the chain reaction caused by excessive power ground fluctuation; the switching transistor is connected to the control module and is used to receive the output signal adjusted by the control module.

[0024] Preferably, the control module may include, but is not limited to, a microcontroller or a drive circuit; the switching transistor may be, but is not limited to, an NMOS transistor or a PMOS transistor, or other switching devices with circuit switching and conduction functions; the comparison module may be, but is not limited to, devices with comparison logic such as comparators, OR gates, and AND gates, so that the comparison module can provide timely feedback when there is excessive voltage fluctuation in the power ground by comparing the voltage fluctuation of the power ground with the reference voltage.

[0025] This embodiment monitors power ground fluctuations by setting up a comparison module and outputs corresponding protection signals based on the power ground fluctuations, thereby ensuring the stable operation of the circuit system and solving the problem that excessive power ground fluctuations affect the performance of some sensitive signals.

[0026] Based on the first embodiment described above, as a preferred embodiment of the present invention, the comparison module in the second embodiment specifically includes: a comparator VC and a reference voltage module; wherein, the comparator is used to compare the voltage fluctuation of the power ground with the magnitude of the reference voltage, thereby monitoring whether excessive fluctuations occur in the power ground; the reference voltage module is used to provide a reference voltage to the comparator. Specifically, as... Figure 2 As shown, the inverting input of comparator VC is connected to the power ground, enabling comparator VC to acquire the voltage fluctuation of the power ground; the non-inverting input of comparator VC is connected to the reference voltage module, enabling comparator VC to obtain a reference voltage for comparison with the voltage fluctuation of the power ground; the output of comparator VC is connected to the control module, enabling the comparator VC to transmit the corresponding protection signal output by the protection signal based on the comparison result between the voltage fluctuation of the power ground and the reference voltage to the control module. Specifically, the reference voltage value provided by the reference voltage module is determined according to the required voltage magnitude and the fluctuation range of the power ground.

[0027] This embodiment sets up a reference voltage module to compare the reference voltage with the power ground voltage fluctuation. Based on the comparison result, it determines whether the circuit is working properly, thereby controlling the output of the protection signal. When the circuit malfunctions, the protection signal is output in a timely manner so that the control module can take timely protective measures, ensure the stable operation of the system, and improve the operational safety of products using this type of protection circuit.

[0028] Preferably, in some embodiments of the present invention, the non-inverting input of the comparator VC can be connected to the power ground, and the inverting input of the comparator VC can be connected to the reference voltage module. This connection port only affects the logic level of the output protection signal and does not affect the function of the comparator module to compare the power ground voltage fluctuation with the reference voltage.

[0029] Preferably, in some embodiments, the power ground fluctuation range is (-0.2, 0.2)V. Then, the reference voltage provided by the reference voltage module is set to 0.2V. When the power ground voltage fluctuation exceeds 0.2V, the comparator outputs a protection signal, i.e. an inverted signal, and sends it to the control module. The control module modulates the output signal to keep the power ground voltage fluctuation within a controllable range.

[0030] Based on the above embodiments, as a preferred embodiment of the present invention, the reference voltage module in the third embodiment of the present invention includes: a first capacitor C1, a first resistor R1, and a second resistor R2; wherein, as shown... Figure 3 As shown, one end of the first capacitor C1 is connected to the non-inverting input of the comparator VC, and the other end of the first capacitor C1 is connected to the power supply ground; one end of the first resistor R1 is connected to the non-inverting input of the comparator VC, and the other end of the first resistor R1 is connected to the power supply VCC; one end of the second resistor R2 is connected to the non-inverting input of the comparator VC, and the other end of the second resistor R2 is connected to the power supply ground. This embodiment uses the first capacitor C1, the first resistor R1, and the second resistor R2 to provide a reference voltage for the comparator VC, achieving effective comparison of power ground voltage fluctuations.

[0031] Based on the above embodiments, as a preferred embodiment of the present invention, in the fourth embodiment of the present invention, as follows: Figure 3 As shown, the comparison module further includes a third resistor R3 as a pull-up resistor; one end of the third resistor R3 is connected to the output terminal of the comparator VC, and the other end of the third resistor R3 is connected to the power supply. Specifically, the third resistor R3 acts as a pull-up resistor in the comparison module to maintain the signal level of the output signal of the comparator VC at a default high level. When the voltage fluctuation of the power ground is too large, the comparator outputs a low-level protection signal so that the control signal can promptly detect the abnormal situation of the power ground.

[0032] Based on the above embodiments, as a preferred embodiment of the present invention, in the fifth embodiment of the present invention, the switching power supply circuit further includes: a supercapacitor SC, an RCD snubber circuit, a transformer T, and a fourth resistor R4; wherein, as shown... Figure 3 As shown, one end of the supercapacitor SC is connected to the power supply ground, and the other end of the supercapacitor SC is connected to one end of the RCD snubber circuit. The other end of the RCD snubber circuit is connected to one end of the transformer, the other end of the transformer T is connected to one end of the switching transistor Q, the other end of the switching transistor Q is connected to one end of the fourth resistor R4, and the other end of the fourth resistor R4 is connected to the output terminal of the control module. Specifically, the fourth resistor R4 serves as a series current-limiting resistor to maintain the normal operation of the base of the switching transistor; when the primary coil of the transformer T operates, there is a momentary large current, and the RCD snubber circuit is used to absorb the voltage spikes caused by the transformer T; the supercapacitor SC serves as a voltage-stabilizing charging capacitor to replenish the momentary current, which can be understood as replenishing electronic energy at the downstream end.

[0033] Preferably, in some embodiments of the present invention, the transformer T may also be, but is not limited to, an inductor or a wireless coil.

[0034] Based on the above embodiments, as a preferred embodiment of the present invention, in the sixth embodiment of the present invention, the RCD absorption circuit specifically includes: a fifth resistor R5, a second capacitor C2, and a diode D; wherein, as shown... Figure 3 As shown, the second capacitor C2 is connected in parallel with the fifth resistor R5. One end of the parallel connection between the second capacitor C2 and the fifth resistor R5 is connected to the other end of the supercapacitor SC, and the other end is connected to the negative terminal of the diode D. The positive terminal of the diode D is connected to one end of the transformer T. Specifically, when the switch Q is turned off, the drain current of the switch Q drops rapidly, the primary coil of the transformer T operates to provide a large instantaneous current, the diode D of the RCD absorption circuit conducts, and the second capacitor C2 is in a charging state. Due to the presence of the second capacitor C2, the drain voltage spike of the switch Q is absorbed, reducing the voltage change rate of the switch Q.

[0035] Based on the above embodiments, as a preferred embodiment of the present invention, in the seventh embodiment of the present invention, the power ground is short-circuited with the power supply ground; wherein, the power ground and the power supply ground are connected through a sixth resistor with a resistance of 0, or through a ferrite bead, or directly connected.

[0036] Based on the above embodiments, as a preferred embodiment of the present invention, the switching transistor in the eighth embodiment of the present invention is configured as an NMOS transistor. Figure 3 As shown, the gate of the NMOS transistor is connected to one end of the fourth resistor, which serves as a series current-limiting resistor to maintain the normal operation of the gate of the NMOS transistor; the gate of the NMOS transistor is connected to the other end of the transformer, and the source of the NMOS transistor is connected to the power ground.

[0037] Preferably, in some embodiments of the present invention, the switching transistor is configured as a PMOS transistor. Based on the design of the switching transistor being configured as a PMOS transistor, the connection method of each module or component in the switching power supply circuit is designed differently according to the logic difference between PMOS transistors and NMOS transistors. The specific design scheme can be obtained by combining the scheme of the present invention with the logic of PMOS transistors.

[0038] Based on the above embodiments, as a preferred embodiment of the present invention, in the ninth embodiment of the present invention, the control module includes a microcontroller unit, and the protection signal is input to the microcontroller unit by the comparison module; after receiving the protection signal, the microcontroller unit adjusts the pulse frequency of the PWM signal it outputs.

[0039] Based on the above embodiments, when the protection circuit is working normally, the control module outputs a PWM signal of a certain frequency. During the continuous switching of the switching transistor Q, if the voltage fluctuation of the power ground is within the normal acceptable range (i.e., the power ground voltage fluctuation is less than the reference voltage), the comparison module outputs a high-level signal by default. When the control module receives the high-level signal output by the comparison module, the PWM signal output by the control module remains unchanged, confirming that the power ground voltage fluctuation is within the normal range. Conversely, if the voltage fluctuation of the power ground is outside the normal acceptable range (i.e., the power ground voltage fluctuation is greater than or equal to the reference voltage) during the continuous switching of the switching transistor Q, the comparison module outputs a low-level protection signal. When the control module receives the low-level protection signal output by the comparison module, the control module adjusts the pulse frequency of its output PWM signal or activates a corresponding protection mechanism to effectively address the problem of excessive power ground voltage fluctuation and improve the stability and safety of the system circuit.

[0040] One embodiment of the present invention provides a chip, the chip including the protection circuit as described in any of the foregoing embodiments.

[0041] Obviously, the above embodiments are only some embodiments of the present invention, not all embodiments, and the technical solutions of various embodiments can be combined with each other. In the above embodiments of the present invention, the descriptions of each embodiment have their own emphasis, and parts not described in detail in a certain embodiment can be referred to the relevant descriptions of other embodiments. In the several embodiments provided by the present invention, it should be understood that the disclosed technical content can be implemented in other ways. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not describe the various possible combinations separately.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A protection circuit, characterized in that, The device includes a switching power supply circuit and a comparator module. The switching power supply circuit includes a control module, a switching transistor, and a power ground. The switching transistor is connected to the power ground. The comparator module is connected to the power ground and is used to compare voltage fluctuations of the power ground to output a protection signal. The switching transistor is connected to the control module. The comparator module is also connected to the control module to transmit the protection signal output by the comparator module to the control module. The control module adjusts its PWM output signal according to the protection signal. The comparison module specifically includes a comparator and a reference voltage module. The inverting input of the comparator is connected to the power ground to collect voltage fluctuations of the power ground. The non-inverting input of the comparator is connected to the reference voltage module to enable the comparator to acquire a reference voltage for comparison with the voltage fluctuations of the power ground. The output of the comparator is connected to the control module to transmit a protection signal, based on the voltage fluctuations of the power ground, to the control module. The comparison module further includes a third resistor as a pull-up resistor; one end of the third resistor is connected to the output terminal of the comparator, and the other end of the third resistor is connected to the power supply. The control module includes a microcontroller unit, and the protection signal is input to the microcontroller unit by the comparison module; after receiving the protection signal, the microcontroller unit adjusts the pulse frequency of its output PWM signal.

2. The protection circuit according to claim 1, characterized in that, The reference voltage module includes: a first capacitor, a first resistor, and a second resistor; wherein, one end of the first capacitor is connected to the non-inverting input of the comparator, and the other end of the first capacitor is connected to the power supply ground; one end of the first resistor is connected to the non-inverting input of the comparator, and the other end of the first resistor is connected to the power supply; one end of the second resistor is connected to the non-inverting input of the comparator, and the other end of the second resistor is connected to the power supply ground.

3. The protection circuit according to claim 2, characterized in that, The switching power supply circuit further includes: a supercapacitor, an RCD snubber circuit, a transformer, and a fourth resistor; wherein, one end of the supercapacitor is connected to the power ground, the other end of the supercapacitor is connected to one end of the RCD snubber circuit, the other end of the RCD snubber circuit is connected to one end of the transformer, the other end of the transformer is connected to one end of the switching transistor, the other end of the switching transistor is connected to one end of the fourth resistor, and the other end of the fourth resistor is connected to the output terminal of the control module.

4. The protection circuit according to claim 3, characterized in that, The RCD absorption circuit specifically includes: a fifth resistor, a second capacitor, and a diode; wherein, the second capacitor is connected in parallel with the fifth resistor, one end of the second capacitor connected in parallel with the fifth resistor is connected to the other end of the supercapacitor, the other end of the second capacitor connected in parallel with the fifth resistor is connected to the negative terminal of the diode, and the positive terminal of the diode is connected to one end of the transformer.

5. The protection circuit according to claim 4, characterized in that, The power ground is shorted to the power supply ground; wherein the power ground and the power supply ground are connected through a sixth resistor with a resistance of 0, or through a ferrite bead, or directly.

6. The protection circuit according to claim 5, characterized in that, The switching transistor is an NMOS transistor; wherein, the gate of the NMOS transistor is connected to one end of the fourth resistor, the gate of the NMOS transistor is connected to the other end of the transformer, and the source of the NMOS transistor is connected to the power ground.

7. A chip, characterized in that, The chip includes a protection circuit as described in any one of claims 1 to 6.

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