Ground bounce noise suppression circuit and circuit board

Abstract

The invention provides a ground bounce noise suppression circuit and a circuit board, which can be applied to the technical field of circuits. The ground bounce noise suppression circuit includes a capacitor and a diode connected in series between a first ground region and a second ground region of a circuit board, in which a forward conduction path of the diode corresponds to a direction from the first ground region to the second ground region, the reference level fluctuation tolerance of the second grounding area is greater than that of the first grounding area, and the projections of the first grounding area and the second grounding area in the thickness direction of the circuit board are not overlapped.

Description

Technical Field

[0001] The present application relates to the field of circuit technology, and more specifically, to a ground bounce noise suppression circuit and a circuit board. Background Art

[0002] Ground bounce noise is caused by sudden changes in ground current, resulting in ground level fluctuations. When the ground level fluctuates significantly, the signals of some components electrically connected to the circuit board may be distorted, or the ground level may remain unstable, causing system malfunctions.

[0003] Therefore, it is necessary to suppress ground bounce noise to ensure signal accuracy and system stability in the system. Summary of the Invention

[0004] In view of this, the present application provides a ground bounce noise suppression circuit and a circuit board.

[0005] According to one aspect of the present application, a ground bounce noise suppression circuit is provided, comprising: a capacitor and a diode, connected in series between a first ground area and a second ground area of ​​a circuit board; wherein a reference level fluctuation tolerance of the second ground area is greater than a reference level fluctuation tolerance of the first ground area, and projections of the first ground area and the second ground area along the thickness direction of the circuit board do not overlap.

[0006] According to another aspect of the present application, a circuit board is provided, comprising a first grounding area and a second grounding area and the above-mentioned ground bounce noise suppression circuit, wherein the reference level fluctuation tolerance of the above-mentioned second grounding area is greater than the reference level fluctuation tolerance of the above-mentioned first grounding area, and the projections of the above-mentioned first grounding area and the above-mentioned second grounding area along the thickness direction of the above-mentioned circuit board do not overlap.

[0007] According to an embodiment of the present application, the ground bounce noise suppression circuit includes a capacitor and a diode connected in series between the first ground area and the second ground area of ​​the circuit board, and the forward conduction path of the diode corresponds to the direction from the first ground area to the second ground area. The capacitor can be used to isolate the DC signal between the second ground area and the first ground area. In addition, by using the capacitor and the diode, the high-frequency ground bounce noise current can be limited to the local loop formed by the second ground area, the capacitor, the diode and the first ground area, reducing its impact on other circuits. In addition, the diode can be used to protect the first ground area from damage caused by instantaneous overvoltage caused by ground bounce noise. According to an embodiment of the present application, DC isolation, high-frequency noise suppression and transient protection are achieved for the first ground area, which greatly reduces the impact of ground bounce noise on the first ground area, ensuring signal accuracy and system stability in the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The above and other objects, features and advantages of the present application will become more apparent through the following description of the embodiments of the present application with reference to the accompanying drawings.

[0009] Figure 1A FIG2 shows a schematic circuit diagram of a ground bounce noise suppression circuit according to a first embodiment of the present application.

[0010] Figure 1B A schematic circuit diagram of a ground bounce noise suppression circuit according to a second embodiment of the present application is shown.

[0011] Figure 2 FIG. 4 shows a schematic circuit diagram of a ground bounce noise suppression circuit according to a third embodiment of the present application.

[0012] Figure 3 A schematic circuit diagram of a ground bounce noise suppression circuit according to a fourth embodiment of the present application is shown.

[0013] Figure 4 FIG. 4 shows a schematic circuit diagram of a ground bounce noise suppression circuit according to a fifth embodiment of the present application.

[0014] Figure 5 A schematic circuit diagram of a ground bounce noise suppression circuit according to a sixth embodiment of the present application is shown.

[0015] Figure 6 A schematic structural diagram of a circuit board according to an embodiment of the present application is shown.

[0016] Figure 7 A schematic structural diagram of a circuit board according to another embodiment of the present application is shown.

[0017] Figure 8 A flow chart of a method for suppressing ground bounce noise according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0018] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present application. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present application. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present application.

[0019] The terms used herein are only for describing specific embodiments and are not intended to limit this application. The terms "comprise," "include," etc. used herein indicate the presence of the features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0020] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0021] When expressions such as "at least one of A, B, and C, etc." are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0022] Because some components electrically connected to the circuit board can experience large ground level fluctuations, signal distortion can occur, or unstable ground levels can cause system malfunctions. Therefore, ground bounce noise must be addressed to ensure accurate signals and system stability.

[0023] A circuit board may include multiple ground regions with different noise tolerances. For example, the circuit board may include a first ground region and a second ground region, where the second ground region has a greater reference level fluctuation tolerance than the first ground region. Hereinafter, the first ground region may also be referred to as the "sensitive ground" and the second ground region may also be referred to as the "noise ground." In one embodiment, a single capacitor may be connected in series between the noise ground and the sensitive ground. However, while a single capacitor solution can bypass high-frequency noise, it lacks transient overvoltage protection and is susceptible to ESD (electrostatic discharge) breakdown. Furthermore, a single TVS diode (transient voltage suppressor diode) solution, due to its excessive junction capacitance (>5pF), can short-circuit the high-frequency ground plane, resulting in isolation degradation exceeding 20dB at 1GHz. This approach is particularly difficult to simultaneously meet the triple requirements of DC isolation, high-frequency noise suppression, and transient protection in high-reliability scenarios such as automotive electronics and SerDes (serializer / deserializer) interfaces.

[0024] In view of this, embodiments of the present application provide a ground bounce noise suppression circuit and a circuit board, which can be applied in the field of circuit technology.

[0025] Figure 1A FIG2 shows a schematic circuit diagram of a ground bounce noise suppression circuit according to a first embodiment of the present application.

[0026] like Figure 1AAs shown, the ground bounce noise suppression circuit according to this embodiment may include a capacitor C and a diode D.

[0027] The capacitor C and the diode D are connected in series between the first grounding area G1 and the second grounding area G2 of the circuit board. In this application, the capacitor C and the diode D can be connected in series, and their specific arrangement positions are not limited. For example, Figure 1A In the example shown, the positions of the capacitor C and the diode D can be swapped.

[0028] The forward conduction path of the diode D (i.e., the path from the anode terminal to the cathode terminal) corresponds to the direction from the first ground region G1 to the second ground region G2. The reference level fluctuation tolerance of the second ground region G2 is greater than the reference level fluctuation tolerance of the first ground region G1.

[0029] The second ground region G2 can be connected to the ground level terminal of a circuit board component that causes relatively large reference level fluctuations. The first ground region G1 can be connected to the ground level terminal of a circuit board component that requires relatively small reference level fluctuations. Here, both the first ground region G1 and the second ground region G2 can be designed to provide a "ground" reference level for the corresponding components.

[0030] For example, the reference level fluctuation range of the first ground region G1 may be ±1.5V, or ±3V, or ±12V, or ±15V. The reference level fluctuation range of the second ground region G2 may be ±0.5V.

[0031] According to an embodiment of the present application, the projections of the first grounding region G1 and the second grounding region G2 along the thickness direction of the circuit board do not overlap. The spacing between the first grounding region G1 and the second grounding region G2 can be greater than 40 milliinches to avoid direct interference coupling between the second grounding region G2 and the first grounding region G1.

[0032] The width of the connection line between capacitor C and diode D can be greater than 10 milliinches. Capacitor C and diode D can be located on the top or bottom surface of the circuit board. The second ground region G2 and the first ground region G1 can be connected to a metal housing of an electronic device electrically connected to the circuit board at a single point, where the metal housing is connected to the ground.

[0033] According to an embodiment of the present application, the width of the connection line between the capacitor C and the diode D is greater than 10 milliinches, so as to prevent the parasitic inductance formed by the connection line from affecting the function of the capacitor C, such as the function of passing high-frequency noise.

[0034] According to an embodiment of the present application, the second ground region G2 and the first ground region G1 can be located on the same layer of the circuit board or on different layers of the circuit board. The second ground region G2 and the series pair of capacitor C and diode D can be located on the same layer of the circuit board or on different layers of the circuit board. The first ground region G1 and the series pair of capacitor C and diode D can be located on the same layer of the circuit board or on different layers of the circuit board.

[0035] If the second ground region G2 and the series pair of capacitor C and diode D are located on different layers of the circuit board, the second ground region G2 and the series pair of capacitor C and diode D are connected via through-holes on the circuit board, referred to as via connections. If the first ground region G1 and the series pair of capacitor C and diode D are located on different layers of the circuit board, the first ground region G1 and the series pair of capacitor C and diode D are connected via vias.

[0036] According to an embodiment of the present application, a device on a circuit board that causes relatively large reference level fluctuations can be electrically connected to the second ground region G2, so that the second ground region G2 provides a ground reference level to the device. On the other hand, the device may introduce relatively large reference level fluctuations into the second ground region G2, causing ground bounce noise.

[0037] For example, the device on the circuit board that causes relatively large reference level fluctuations may be a crystal oscillator or a DC-DC converter (DC-DC converter).

[0038] According to embodiments of the present application, a device on a circuit board that requires relatively small reference level fluctuations can be electrically connected to the first ground region G1, so that the first ground region G1 provides a ground reference level to the device. It is desirable that fluctuations in the reference level provided by the first ground region G1 do not affect the device on the circuit board that requires relatively small reference level fluctuations, preventing signal distortion in the device and preventing system malfunctions due to unstable levels.

[0039] For example, the device on the circuit board that requires relatively small reference level fluctuation may be a device that generates a wake-up signal, a device that generates a reset signal, a device that generates an initialization signal, or various types of sensors.

[0040] For example, if a crystal oscillator electrically connected to the second ground region provides a clock signal for device A on a circuit board that requires relatively small reference level fluctuations, and device A on the circuit board that requires relatively small reference level fluctuations is also electrically connected to the first ground region G1, the ground bounce noise suppression circuit provided in the embodiments of the present application can be connected in series between the first ground region G1 and the second ground region G2. Since the ground bounce noise suppression circuit provided in the embodiments of the present application includes a capacitor C and a diode D, which are connected in series between the first ground region G1 and the second ground region G2 of the circuit board, and the forward conduction path of the diode D corresponds to the direction from the first ground region G1 to the second ground region G2, a return current path can be formed between the first ground region G1 and the second ground region G2 through the capacitor C and the diode D. This can also reduce or even prevent the impact of ground bounce noise at the second ground region G2 on the reference level of the first ground region G1.

[0041] According to an embodiment of the present application, when a device on the circuit board causing relatively large reference level fluctuation is electrically connected to the second ground region G2 , the capacitor C can isolate the DC signal in the ground bounce noise from the first ground region G1 .

[0042] According to the embodiments of the present application, the primary function of capacitor C is to provide a low-impedance return path for high-frequency ground bounce noise, confining the high-frequency ground bounce noise current to a local loop and reducing its impact on other circuits (i.e., achieving high-frequency "bridging"). Simultaneously, capacitor C isolates the DC signal in the ground bounce noise from the first ground region G1. Furthermore, capacitor C blocks the difference between DC and low-frequency levels. When medium- and high-frequency noise couples to the first ground region G1, it can flow back to the second ground region G2 through capacitor C and forward-directed diode D, significantly reducing the noise return path and alleviating loop radiation.

[0043] According to the embodiments of the present application, the primary function of the unidirectional diode D is to clamp high mid-frequency noise that may arise between the first ground region G1 and the second ground region G2. While ensuring high-frequency signal return, it suppresses potential mid-frequency voltage in the second ground region G2 and reduces voltage fluctuations in the first ground region G1, thereby protecting the reference level of sensitive signals. Furthermore, the reverse junction capacitance of diode D can be utilized to create a high-frequency path that bypasses high-frequency noise current to the chassis ground. Here, the chassis ground can be the reference ground formed by connecting the metal casing of the electronic device to which the circuit board is electrically connected and the earth.

[0044] According to an embodiment of the present application, the ground bounce noise suppression circuit includes a capacitor and a diode connected in series between the first ground area and the second ground area of ​​the circuit board, and the forward conduction path of the diode corresponds to the direction from the first ground area to the second ground area. The capacitor can be used to isolate the DC signal between the second ground area and the first ground area. In addition, by using the capacitor and the diode, the high-frequency ground bounce noise current can be limited to the local loop formed by the second ground area, the capacitor, the diode and the first ground area, reducing its impact on other circuits. In addition, the diode can be used to protect the first ground area from damage caused by transient overvoltage caused by ground bounce noise. According to an embodiment of the present application, DC isolation, high-frequency noise suppression and transient protection are achieved for the first ground area, which greatly reduces the impact of ground bounce noise on the first ground area, ensuring the accuracy of signals in the system and the stability of the system.

[0045] According to an embodiment of the present application, since the capacitor and diode included in the ground bounce noise suppression circuit are connected in series between the first and second ground regions of the circuit board, and the forward conduction path of the diode corresponds to the direction from the first ground region to the second ground region, it is possible to ensure that the capacitor and diode form a return path between the first and second ground regions when a device on the circuit board that causes relatively large reference level fluctuations is electrically connected to a device on the circuit board that requires relatively small reference level fluctuations, and when the device on the circuit board that causes relatively large reference level fluctuations is electrically connected to the second ground region, and when the device on the circuit board that requires relatively small reference level fluctuations is electrically connected to the first ground region. At the same time, ground bounce noise at the second ground region can be prevented from affecting the reference level of the first ground region.

[0046] According to the ground bounce noise suppression circuit provided in the embodiment of the present application, a unidirectional diode and a capacitor combination are placed between the second ground region G2 and the first ground region G1 to prevent the ground bounce noise from affecting the first ground region G1.

[0047] For example, a first end of the capacitor C is electrically connected to the first ground region G1 , a second end of the capacitor C is electrically connected to an anode end of the diode D, and a cathode end of the diode D is electrically connected to the second ground region G2 .

[0048] According to an embodiment of the present application, the ground bounce noise suppression circuit includes a capacitor C whose first end is electrically connected to the first ground region G1, a second end of the capacitor C is electrically connected to the anode end of the diode D, and a cathode end of the diode D is electrically connected to the second ground region G2. This ensures that the capacitor and diode are connected in series between the first and second ground regions of the circuit board, and that the forward conduction path of the diode corresponds to the direction from the first ground region to the second ground region. Consequently, the capacitor C can be used to isolate the DC signal between the second ground region G2 and the first ground region G1. Simultaneously, the capacitor C and diode D can be used to confine the high-frequency ground bounce noise current to the local loop formed by the second ground region G2, the capacitor C, the diode D, and the first ground region G1, reducing its impact on other circuits. Furthermore, the diode D can be used to protect the first ground region G1 from transient overvoltage damage caused by ground bounce noise. Thus, DC isolation, high-frequency noise suppression, and transient protection are achieved for the first ground region G1, significantly reducing the impact of ground bounce noise on the first ground region G1 and ensuring signal accuracy and system stability in the system.

[0049] Figure 1B A schematic circuit diagram of a ground bounce noise suppression circuit according to a second embodiment of the present application is shown.

[0050] like Figure 1B As shown, the ground bounce noise suppression circuit includes a capacitor C, a diode D, and a bleeder resistor R connected in parallel with diode D. Capacitor C and diode D are connected in series between the first ground area G1 and the second ground area G2 of the circuit board. The forward conduction path of diode D corresponds to the direction from the first ground area G1 to the second ground area G2.

[0051] For example, the resistance of the bleeder resistor R may be 1 MΩ.

[0052] According to an embodiment of the present application, a bleeder resistor R is connected in parallel across the diode D to prevent charge accumulation from breaking down the diode D. A 1MΩ bleeder resistor R ensures that the charge accumulated on both sides of the diode D is slowly released without affecting the reference level of the sensitive signal, i.e., the reference level of the first ground region G1. It also ensures that there is no prolonged level difference across the diode D, which could damage the diode D. Here, the sensitive signal may be a signal transmitted by a device on a circuit board that requires relatively small reference level fluctuations.

[0053] Figure 2 FIG. 4 shows a schematic circuit diagram of a ground bounce noise suppression circuit according to a third embodiment of the present application.

[0054] like Figure 2As shown, the ground bounce noise suppression circuit may include a capacitor C, a plurality of diodes D, a plurality of first switches K1 electrically connected to the plurality of diodes D, a signal acquisition module, and a control module.

[0055] In the initial state, capacitor C and any diode D can be connected in series between the first ground region G1 and the second ground region G2 of the circuit board. The forward conduction path of any diode D corresponds to the direction from the first ground region G1 to the second ground region G2. For example, in the initial state, the capacitance value of capacitor C can be 67Nf, and diode D can be a conventional diode.

[0056] Each diode D is connected in series with a corresponding first switch K1, and the series pairs of diodes D and corresponding first switches K1 are connected in parallel. The signal acquisition module is electrically connected to the second ground region G2. The control module is electrically connected to the plurality of first switches K1 and the signal acquisition module.

[0057] The signal acquisition module may be configured to acquire a reference level of the second ground region G2 .

[0058] The control module may be configured to control the plurality of first switches K1 according to the reference level collected by the signal collection module, so as to connect a target diode among the plurality of diodes D in series between the first ground region G1 and the second ground region G2 .

[0059] For example, the signal acquisition module can be a distributed sensor array. Micro voltage sensors (e.g., differential detection circuits based on operational amplifiers) can be integrated in key areas of the circuit board (e.g., near high-speed chip pins or at the power / ground plane interface) to acquire the reference voltage level of the second ground region G2 in real time. The control module can then determine the voltage amplitude and frequency characteristics of the ground bounce noise.

[0060] For example, the control module may be an MCU (Microcontroller Unit) or a CPU (Central Processing Unit).

[0061] According to an embodiment of the present application, by using a signal acquisition module to collect the reference level of the second grounding area, and then using a control module to control multiple first switches according to the reference level collected by the signal acquisition module, it is possible to automatically adjust the target diode suitable for suppressing ground bounce noise, and connect the target diodes among the multiple diodes D in series between the first grounding area and the second grounding area to provide better ground bounce noise suppression function.

[0062] For example, the control module can control the plurality of first switches according to the reference levels collected by the signal collection module based on a noise classification model of a neural network, a related noise matching optimization algorithm, etc. For example, the control module can predict the noise frequency according to a plurality of reference levels collected by the collection module in a predetermined period of time. Then, the target diode type is predicted according to the noise frequency and the plurality of reference levels.

[0063] For example, the plurality of diodes D can include a first diode, a second diode, and a third diode. The first diode can be a conventional diode, the second diode can be a Schottky diode, and the third diode can be a TSV diode.

[0064] The control module can also be configured to determine the noise frequency according to a plurality of reference levels collected in a predetermined period of time. Based on the noise frequency being less than a predetermined frequency and the number of reference levels greater than a predetermined voltage being less than a predetermined number, the first switch electrically connected to the first diode is turned on, and the first switch electrically connected to other diodes is turned off. Based on the noise frequency being less than a predetermined frequency and the number of reference levels greater than a predetermined voltage being greater than or equal to a predetermined number, the first switch electrically connected to the second diode is turned on, and the first switch electrically connected to other diodes is turned off. Based on the noise frequency being greater than or equal to a predetermined frequency, the first switch electrically connected to the third diode is turned on, and the first switch electrically connected to other diodes is turned off.

[0065] According to embodiments of the present application, the predetermined voltage, the predetermined frequency, and the predetermined number can be selected according to actual conditions, which are not limited herein. For example, the predetermined voltage can be 50V, the predetermined frequency can be 200MHz, and the predetermined number can be 2.

[0066] According to embodiments of the present application, the noise frequency is the frequency of the ground bounce noise.

[0067] According to embodiments of the present application, the control module can extract characteristic parameters such as peak value and frequency spectrum distribution of the ground bounce noise according to a plurality of reference levels collected in a predetermined period of time, and obtain the noise frequency according to the characteristic parameters.

[0068] According to embodiments of the present application, the control module can analyze the intensity, main frequency, and trend of the current noise according to the characteristic parameters, and calculate the optimal suppression strategy.

[0069] According to embodiments of the present application, in the case where the noise frequency is less than 200MHz and the number of reference levels greater than 50V is less than 2, it indicates that there is no ESD at the second ground region G2, and the ground bounce noise suppression circuit has no ESD prevention requirement. At this time, the ground bounce noise suppression circuit can use a conventional diode to suppress the ground bounce noise. The reverse junction capacitance of the conventional diode can be less than 1pF.

[0070] According to an embodiment of the present application, if the noise frequency is less than 200 MHz and the number of multiple reference levels greater than 50 V is greater than or equal to 2, it indicates that ESD is present in the second ground region G2 and there are large voltage fluctuations. In this case, the ground bounce noise suppression circuit can use a Schottky diode.

[0071] According to an embodiment of the present application, when the noise frequency is greater than or equal to 200 MHz, it indicates that the ground bounce noise frequency in the second ground region G2 changes rapidly and there may also be large voltage fluctuations. In this case, the ground bounce noise suppression circuit can use TSV diodes.

[0072] According to an embodiment of the present application, the noise frequency is determined by utilizing a control module based on multiple reference levels collected during a predetermined period. Based on the fact that the noise frequency is less than a predetermined frequency and the number of multiple reference levels greater than a predetermined voltage is less than a predetermined number, the first switch electrically connected to the first diode is controlled to be closed, and the first switch electrically connected to the other diodes is controlled to be disconnected; based on the fact that the noise frequency is less than a predetermined frequency and the number of multiple reference levels greater than a predetermined voltage is greater than or equal to a predetermined number, the first switch electrically connected to the second diode is controlled to be closed, and the first switch electrically connected to the other diodes is controlled to be disconnected; based on the fact that the noise frequency is greater than or equal to a predetermined frequency, the first switch electrically connected to the third diode is controlled to be closed, and the first switch electrically connected to the other diodes is controlled to be disconnected. This allows the diode that best suppresses ground bounce noise to be automatically screened from conventional diodes, Schottky diodes, and TSV diodes, so that the target diode among the multiple diodes can be connected in series between the first grounding area and the second grounding area, providing a better ground bounce noise suppression function.

[0073] Figure 3 A schematic circuit diagram of a ground bounce noise suppression circuit according to a fourth embodiment of the present application is shown.

[0074] like Figure 3 As shown, the ground bounce noise suppression circuit may include multiple capacitors C, a diode D, a signal acquisition module, a control module, and multiple second switches K2 electrically connected to the multiple capacitors C. The multiple capacitors C have different capacitance values.

[0075] In the initial state, a diode D can be connected in series with any capacitor C between the first ground region G1 and the second ground region G2 of the circuit board. The forward conduction path of the diode D corresponds to the direction from the first ground region G1 to the second ground region G2. For example, in the initial state, the capacitance value of the capacitor C can be 67Nf, and the diode D can be a conventional diode.

[0076] Each capacitor C is connected in series with the corresponding second switch K2, and the series pairs of the capacitors C and the corresponding second switches K2 are connected in parallel with each other.

[0077] The signal acquisition module is electrically connected to the components on the circuit board that are electrically connected to the first grounding area G1. The control module is electrically connected to the plurality of second switches K2 and the signal acquisition module.

[0078] The signal acquisition module is configured to acquire identification information of the device. The control module is configured to determine the frequency of the signal transmitted by the device based on the device identification information; and control the plurality of second switches K2 based on the signal frequency to connect a target capacitor from the plurality of capacitors in series between the first ground region and the second ground region.

[0079] According to an embodiment of the present application, by utilizing a signal acquisition module to collect identification information of a device, utilizing a control module to determine the signal frequency of a signal transmitted by the device based on the identification information of the device, and controlling a plurality of second switches based on the signal frequency, it is possible to automatically screen the optimal target capacitor from a plurality of capacitors with different capacitance values, and utilize the target capacitor to conduct a return path between the first grounding area and the second grounding area.

[0080] Figure 4 FIG. 4 shows a schematic circuit diagram of a ground bounce noise suppression circuit according to a fifth embodiment of the present application.

[0081] like Figure 4 As shown, the ground bounce noise suppression circuit may include multiple capacitors C, multiple diodes D, multiple first switches K1 electrically connected to the multiple diodes D, a signal acquisition module, a control module, and multiple second switches K2 electrically connected to the multiple capacitors C. The capacitance values ​​of the multiple capacitors C are different. Figure 4 The diode D and the first switch K1 in Figure 2 The diode D and the first switch K1 in FIG have similar structures and functions, and for the sake of simplicity, they are not described here in detail.

[0082] Each capacitor C is connected in series with the corresponding second switch K2, and the series pairs of the capacitors C and the corresponding second switches K2 are connected in parallel with each other.

[0083] Figure 4 The signal acquisition module in Figure 2 The signal acquisition module is further electrically connected to the device electrically connected to the first grounding area G1 on the circuit board. The signal acquisition module is further configured to acquire identification information of the device.

[0084] Figure 4 The control module in Figure 2The control module is further electrically connected to a plurality of second switches K2. The control module is further configured to determine the signal frequency of the signal transmitted by the device based on the device identification information; and control the plurality of second switches K2 based on the signal frequency to connect a target capacitor among the plurality of capacitors in series between the first ground region G1 and the second ground region G2.

[0085] exist Figure 4 In the embodiment, the second grounding region G2 and the first grounding region G1 are both connected to the chassis ground G3 at a single point. The chassis ground G3 is a reference ground formed by connecting the metal casing of the electronic device to which the circuit board is electrically connected to the earth.

[0086] According to an embodiment of the present application, any device electrically connected to the first ground region G1 transmits a signal with a certain frequency. Therefore, the control module can pre-configure the frequency of the signal transmitted by the device electrically connected to the first ground region G1. After the signal acquisition module collects the device's identification information, the control module can determine the capacitor corresponding to the pre-configured signal frequency based on the corresponding frequency and then control the second switch K2 corresponding to the capacitor.

[0087] For example, the signal acquisition module may also be electrically connected to multiple devices on the circuit board that are electrically connected to the first ground region G1. The control module may also determine the signal frequencies of signals transmitted by the multiple devices based on their respective identification information, and control the multiple second switches K2 based on the multiple signal frequencies to connect target capacitors from the multiple capacitors in series between the first ground region and the second ground region, thereby forming a return path between the first ground region and the second ground region for each of the multiple devices. The multiple devices may be individual devices electrically connected to the first ground region G1. The multiple devices may also be individual devices electrically connected to both the first ground region G1 and the device on the circuit board that causes relatively large reference level fluctuations. In this case, the device on the circuit board that causes relatively large reference level fluctuations is electrically connected to the second ground region G2.

[0088] According to an embodiment of the present application, by utilizing a signal acquisition module to collect identification information of a device, utilizing a control module to determine the signal frequency of a signal transmitted by the device based on the identification information of the device, and controlling a plurality of second switches based on the signal frequency, it is possible to automatically screen the optimal target capacitor from a plurality of capacitors with different capacitance values, and utilize the target capacitor to conduct a return path between the first grounding area and the second grounding area.

[0089] According to the embodiments of the present application, Figure 2The shown bleed resistor R can be a voltage-controlled variable resistor. The voltage across the diode D can also be collected by the signal collection module, and then the control module can determine the target resistance value of the bleed resistor R according to the voltage across the diode D, and adjust the bleed resistor R to the target resistance value.

[0090] According to the ground bounce noise suppression circuit provided in the present application, the system function abnormality caused by the abnormal reference level of sensitive signals due to the excessively high ground bounce noise caused by the loop in which the DC-DC converter is located can be improved.

[0091] According to the embodiments of the present application, the ground bounce noise suppression circuit includes a signal collection module and a control module, which can automatically adjust the applicable capacitors and / or diodes, increase signal feedback, and provide better ground bounce noise suppression function.

[0092] Figure 5 A schematic circuit diagram of a ground bounce noise suppression circuit according to a sixth embodiment of the present application is shown.

[0093] As shown in Figure 5 The projection of the first land area of the circuit board and the second land area of the circuit board along the thickness direction of the circuit board does not overlap.

[0094] In the case where the length of the first land area and the second land area in the first direction is greater than the predetermined length, the ground bounce noise suppression circuit can include a plurality of series-connected capacitor C and diode D pairs. Here, each series-connected capacitor C and diode D pair is connected in series between the first land area and the second land area of the circuit board, and the forward conduction path of the diode D corresponds to the direction from the first land area to the second land area. The reference level fluctuation tolerance of the second land area is greater than that of the first land area.

[0095] According to the embodiments of the present application, the predetermined length can be selected according to actual conditions, which is not limited here. For example, the predetermined length can be 5 cm.

[0096] The plurality of series-connected capacitor C and diode D pairs are each electrically connected to the first land area and the second land area via a corresponding connection point. The spacing L between adjacent connection points in the first direction is less than or equal to the predetermined length. The first direction is perpendicular to the second direction. The first land area and the second land area are spaced apart in the second direction.

[0097] For example, a series pair of a capacitor C and a diode D can be electrically connected to a first connection point A1 on the first ground region and a first connection point B1 on the second ground region. Another series pair of a capacitor C and a diode D can be electrically connected to a second connection point A2 on the first ground region and a second connection point B2 on the second ground region. Yet another series pair of a capacitor C and a diode D can be electrically connected to a third connection point A3 on the first ground region and a third connection point B3 on the second ground region. The first connection point A1 on the first ground region and the second connection point A2 on the first ground region are adjacent to each other in the first direction. The second connection point A2 on the first ground region and the third connection point A3 on the first ground region are adjacent to each other in the first direction. The first connection point B1 on the second ground region and the second connection point B2 on the second ground region are adjacent to each other in the first direction. The second connection point B2 on the second ground region and the third connection point B3 on the second ground region are adjacent to each other in the first direction.

[0098] The distance L between A1 and A2 is less than or equal to 5 cm. The distance L between A2 and A3 is less than or equal to 5 cm. The distance L between B1 and B2 is less than or equal to 5 cm. The distance L between B2 and B3 is less than or equal to 5 cm.

[0099] According to the embodiments of the present application, Figure 5 The ground bounce noise suppression circuit shown may further include a signal acquisition module, a control module, and a plurality of signal acquisition modules respectively provided at the respective connection points in the first direction. Figure 4 The signal acquisition module may include a plurality of capacitors C, a plurality of diodes D, a plurality of first switches K1 electrically connected to the plurality of diodes D, and a plurality of second switches K2 electrically connected to the plurality of capacitors C. Figure 4 The structure and function of the signal acquisition module shown in FIG. Figure 4 On the basis of the control module shown, the plurality of first switches K1 and the plurality of second switches K2 at the respective connection points are electrically connected, and the plurality of first switches K1 and the plurality of second switches K2 at the respective connection points are controlled simultaneously to electrically connect the series pairs of the plurality of target diodes and the target capacitors to the first ground area and the second ground area via the corresponding connection points.

[0100] According to an embodiment of the present application, when the length of the first grounding area and the second grounding area along the first direction is greater than a predetermined length, the ground bounce noise suppression circuit includes a plurality of series pairs of capacitors and diodes, and the plurality of series pairs of capacitors C and diodes D are each electrically connected to the first grounding area and the second grounding area via a corresponding connection point. The spacing between adjacent connection points in the first direction is less than or equal to the predetermined length, the first direction is perpendicular to the second direction, and the first grounding area and the second grounding area are spaced apart in the second direction. When the area of ​​the two grounding areas is relatively large and there are relatively many signals involved, the signal return path can be avoided from being too long, thereby speeding up the signal return speed.

[0101] Figure 6 A schematic structural diagram of a circuit board according to an embodiment of the present application is shown.

[0102] like Figure 6 As shown, the circuit board includes a second grounding area, a first grounding area, and a ground bounce noise suppression circuit. The reference level fluctuation tolerance of the second grounding area is greater than the reference level fluctuation tolerance of the first grounding area. The projections of the first and second grounding areas along the thickness direction of the circuit board do not overlap. The ground bounce noise suppression circuit may include a capacitor C and a diode D. The ground bounce noise suppression circuit can be any of the above-mentioned ground bounce noise suppression circuits and will not be described here for simplicity.

[0103] According to an embodiment of the present application, the distance between the second grounding area and the first grounding area is greater than 40 milliinches.

[0104] According to the embodiment of the present application, the copper plating spacing between the second grounding area and the first grounding area is ensured to be greater than 40 milliinches, thereby avoiding direct interference coupling between the second grounding area and the first grounding area.

[0105] Figure 7 A schematic structural diagram of a circuit board according to another embodiment of the present application is shown.

[0106] like Figure 7 As shown, the circuit board includes a second grounding area, a first grounding area, and a ground bounce noise suppression circuit. Here, the reference level fluctuation tolerance of the second grounding area is greater than the reference level fluctuation tolerance of the first grounding area. The projections of the first and second grounding areas along the thickness direction of the circuit board do not overlap. Here, the ground bounce noise suppression circuit may include a capacitor C and a diode D. The ground bounce noise suppression circuit can be any of the above-mentioned ground bounce noise suppression circuits and, for the sake of brevity, will not be described in detail here.

[0107] The second grounding area and the first grounding area are connected at a single point to a metal shell of an electronic device electrically connected to the circuit board, and the metal shell is connected to the ground.

[0108] For example, the second grounding area and the first grounding area can be directly connected to the metal housing using screw holes on the circuit board or other means. Sufficient grounding holes can also be provided on the circuit board to discharge the interference level generated by the second grounding area through the lowest impedance path. A grounding resistance of less than 0.1Ω can be used as an indicator of sufficient grounding strength. The grounding resistance is the resistance between the second grounding area and the metal housing, and the resistance between the first grounding area and the metal housing. A grounding resistance of less than 0.1Ω indicates that the grounding is sufficiently strong.

[0109] According to the embodiments of the present application, Figure 7 The illustrated circuit board provides a low-impedance return path for high-frequency ground bounce noise, confining the high-frequency ground bounce noise current to a local loop and reducing its impact on other circuits (i.e., achieving high-frequency "bridging"). High-frequency ground bounce noise can flow from the second ground region through capacitor C and diode D, as well as the first ground region, to the chassis ground. Because the voltage fluctuations caused by high-frequency ground bounce noise are small, even if the high-frequency ground bounce noise is discharged through the first ground region, it will not affect the reference level of the first ground region. Here, the chassis ground can be the reference ground formed by connecting the metal casing of the electronic device to which the circuit board is electrically connected to the earth.

[0110] at the same time Figure 7 In the circuit board shown, when medium and high frequency noise is coupled to the first ground area, it can flow back to the second ground area through capacitor C and forward diode D, greatly reducing the noise return path and alleviating loop radiation.

[0111] At the same time, when a device on the circuit board requires a relatively small reference voltage fluctuation and is electrically connected to the first ground area and a device on the circuit board that causes a relatively large reference level fluctuation, and the device on the circuit board that causes a relatively large reference level fluctuation is electrically connected to the second ground area, a return path can be formed between the first ground area and the second ground area through the capacitor C and the forward diode D.

[0112] According to an embodiment of the present application, the second grounding area and the first grounding area are connected to the metal casing of the electronic device electrically connected to the circuit board at a single point, and the metal casing is connected to the ground. High-frequency noise can be discharged through the reference ground formed after the metal casing of the electronic device electrically connected to the circuit board is connected to the ground, thereby preventing high-frequency noise interference from coupling to the internal signal of the circuit board.

[0113] Based on the above-mentioned ground bounce noise suppression circuit, the present application provides a ground bounce noise suppression method.

[0114] Figure 8 A flow chart of a method for suppressing ground bounce noise according to an embodiment of the present application is shown.

[0115] like Figure 8 As shown, the ground bounce noise suppression method may include operations S810 to S820. Figure 8 The ground bounce noise suppression method shown can be applied to the above-mentioned ground bounce noise suppression circuit.

[0116] In operation S810, a DC component in a noise signal is isolated from a first ground region by a capacitor.

[0117] In operation S820 , a high-frequency noise return path is formed between the first ground region and the second ground region through the capacitor and the diode.

[0118] According to an embodiment of the present application, the ground bounce noise suppression method may also include: a device requiring relatively small reference voltage fluctuations on a circuit board is electrically connected to a first ground area and a device on the circuit board that causes relatively large reference level fluctuations, and when the device on the circuit board that causes relatively large reference level fluctuations is electrically connected to the second ground area, a return path is formed between the first ground area and the second ground area through a capacitor and a diode.

[0119] According to an embodiment of the present application, the ground bounce noise suppression method may further include: isolating static electricity in the ground bounce noise at the second ground region from the first ground region through a diode.

[0120] It should be noted that the ground bounce noise suppression method part in the embodiment of the present application corresponds to the ground bounce noise suppression circuit part in the embodiment of the present application. The description of the ground bounce noise suppression method part specifically refers to the ground bounce noise suppression circuit part, which will not be repeated here.

[0121] It will be understood by those skilled in the art that the features described in the various embodiments of this application may be combined and / or coupled in various ways, even if such combinations or couplings are not explicitly described in this application. In particular, the features described in the various embodiments of this application may be combined and / or coupled in various ways without departing from the spirit and teachings of this application. All such combinations and / or couplings fall within the scope of this application.

[0122] The embodiments of the present application have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present application. Although each embodiment has been described above separately, this does not mean that the measures in each embodiment cannot be advantageously used in combination. The scope of the present application is defined by the accompanying embodiments and their equivalents. Without departing from the scope of the present application, those skilled in the art may make various substitutions and modifications, and these substitutions and modifications should all fall within the scope of the present application.

Claims

1. A ground bounce noise suppression circuit, characterized in that: The ground bounce noise suppression circuit includes: a capacitor and a diode connected in series between the first ground area and the second ground area of ​​the circuit board; wherein the forward conduction path of the diode corresponds to a direction from the first grounding region to the second grounding region; The reference level fluctuation tolerance of the second grounding area is greater than the reference level fluctuation tolerance of the first grounding area, and projections of the first grounding area and the second grounding area along the thickness direction of the circuit board do not overlap.

2. The ground bounce noise suppression circuit according to claim 1, characterized in that: A first end of the capacitor is electrically connected to the first ground region, a second end of the capacitor is electrically connected to an anode end of the diode, and a cathode end of the diode is electrically connected to the second ground region.

3. The ground bounce noise suppression circuit according to claim 1, wherein: The ground bounce noise suppression circuit further includes: A bleeder resistor is connected in parallel with the diode.

4. The ground bounce noise suppression circuit according to claim 1, wherein: There are multiple diodes; The ground bounce noise suppression circuit further includes: a plurality of first switches electrically connected to a plurality of diodes, each of the diodes being connected in series with a corresponding first switch, and series pairs of the diodes and the corresponding first switches being connected in parallel with each other; a signal acquisition module, electrically connected to the second ground area and configured to acquire a reference level of the second ground area; A control module is electrically connected to the plurality of first switches and the signal acquisition module, and is configured to control the plurality of first switches according to a reference level acquired by the signal acquisition module so as to connect a target diode among the plurality of diodes in series between the first ground region and the second ground region.

5. The ground bounce noise suppression circuit according to claim 4, characterized in that: The plurality of diodes include: a first diode, a second diode and a third diode; The control module is further configured to: determining a noise frequency based on a plurality of reference levels collected during a predetermined period of time; Based on the fact that the noise frequency is less than a predetermined frequency and the number of the plurality of reference levels greater than a predetermined voltage is less than a predetermined number, controlling the first switch electrically connected to the first diode to be closed, and controlling the first switches electrically connected to the other diodes to be open; Based on the fact that the noise frequency is less than the predetermined frequency and the number of the plurality of reference levels greater than the predetermined voltage is greater than or equal to the predetermined number, controlling the first switch electrically connected to the second diode to be closed, and controlling the first switches electrically connected to the other diodes to be open; Based on the fact that the noise frequency is greater than or equal to the predetermined frequency, the first switch electrically connected to the third diode is controlled to be closed, and the first switches electrically connected to the other diodes are controlled to be opened.

6. The ground bounce noise suppression circuit according to claim 5, characterized in that: The first diode is a conventional diode, the second diode is a Schottky diode, and the third diode is a TSV diode.

7. The ground bounce noise suppression circuit according to claim 4, characterized in that: There are multiple capacitors, and the capacitance values ​​of the multiple capacitors are different; The ground bounce noise suppression circuit further includes: a plurality of second switches electrically connected to the plurality of capacitors, each of the capacitors being connected in series with a corresponding second switch, and each series pair of the capacitors and the corresponding second switches being connected in parallel with each other; The signal acquisition module is electrically connected to a device on the circuit board that is electrically connected to the first grounding area, and is further configured to acquire identification information of the device; The control module is electrically connected to the plurality of second switches and is further configured to: determining a signal frequency of a signal transmitted by the device according to the identification information of the device; The plurality of second switches are controlled according to the signal frequency so as to connect a target capacitor among the plurality of capacitors in series between the first ground region and the second ground region.

8. The ground bounce noise suppression circuit according to claim 1, wherein: The line width of the connecting line between the capacitor and the diode is greater than 10 milliinches; The capacitor and the diode are located on a top surface or a bottom surface of the circuit board.

9. The ground bounce noise suppression circuit according to claim 1, wherein: When the length of the first grounding area and the second grounding area along the first direction is greater than a predetermined length, the ground bounce noise suppression circuit includes a plurality of series pairs of capacitors and diodes, wherein the plurality of series pairs of capacitors and diodes are each electrically connected to the first grounding area and the second grounding area via a corresponding connection point, the spacing between adjacent connection points in the first direction is less than or equal to the predetermined length, the first direction is perpendicular to the second direction, and the first grounding area and the second grounding area are spaced apart in the second direction.

10. A circuit board, characterized in that: The ground bounce noise suppression circuit comprises a first grounding area and a second grounding area and the ground bounce noise suppression circuit according to any one of claims 1 to 9, wherein the reference level fluctuation tolerance of the second grounding area is greater than the reference level fluctuation tolerance of the first grounding area, and the projections of the first grounding area and the second grounding area along the thickness direction of the circuit board do not overlap.

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