Geophone noise suppression circuit and circuit board

Abstract

The application 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 comprises a capacitor and a diode, which are connected in series between a first grounding area and a second grounding area of a circuit board, wherein a forward conduction path of the diode corresponds to a direction from the first grounding area to the second grounding area, wherein a reference level fluctuation tolerance of the second grounding area is greater than a reference level fluctuation tolerance of the first grounding area, and projections of the first grounding area and the second grounding area along a thickness direction of the circuit board do not overlap.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit, and more particularly, to a ground bounce noise suppression circuit and a circuit board. BACKGROUND

[0002] Ground bounce noise is caused by ground current mutation. When the ground level fluctuates greatly, some devices electrically connected to the circuit board will have distorted signals or unstable levels, which will cause system malfunctions.

[0003] Therefore, it is necessary to suppress ground bounce noise to ensure accurate signals in the system and system stability. SUMMARY

[0004] Therefore, the present application provides a ground bounce noise suppression circuit and a circuit board.

[0005] According to an 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 region and a second ground region of a circuit board; wherein a reference level fluctuation tolerance of the second ground region is greater than a reference level fluctuation tolerance of the first ground region, and projections of the first ground region and the second ground region along a 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 ground region and a second ground region and the above-mentioned ground bounce noise suppression circuit, wherein a reference level fluctuation tolerance of the second ground region is greater than a reference level fluctuation tolerance of the first ground region, and projections of the first ground region and the second ground region along a thickness direction of the circuit board do not overlap.

[0007] According to an embodiment of the present application, the ground bounce noise suppression circuit comprises a capacitor and a diode connected in series between a first ground region and a second ground region of a circuit board, and the forward conduction path of the diode corresponds to the direction from the first ground region to the second ground region. The capacitor can be used to isolate the direct current signal between the second ground region and the first ground region. In addition, by using the capacitor and the diode, the high-frequency ground bounce noise current can be limited in a local loop formed by the second ground region, the capacitor, the diode and the first ground region, thereby reducing its impact on other circuits. In addition, the diode can be used to protect the first ground region from the instantaneous overvoltage caused by the ground bounce noise. According to the embodiment of the present application, the first ground region is directly isolated, high-frequency noise is suppressed, and transient protection is provided, which greatly reduces the impact of ground bounce noise on the first ground region, and ensures accurate signals in the system and system stability. BRIEF DESCRIPTION OF DRAWINGS

[0008] The above and other objects, features and advantages of the present application will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which:

[0009] Figure 1A A schematic circuit diagram of a geophone noise suppression circuit according to a first embodiment of the present application is shown.

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

[0011] Figure 2 A schematic circuit diagram of a geophone noise suppression circuit according to a third embodiment of the present application is shown.

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

[0013] Figure 4 A schematic circuit diagram of a geophone noise suppression circuit according to a fifth embodiment of the present application is shown.

[0014] Figure 5 A schematic circuit diagram of a geophone 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 flowchart of a geophone noise suppression method according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0018] Embodiments of the present application will be described herein below with reference to the accompanying drawings. It is to be understood, however, that the description is merely exemplary and is not intended to limit the scope of the present application. In the following detailed description of the embodiments of the present application, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that one or more embodiments of the present application can be practiced without these specific details. In other instances, well-known structures and

[0019] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the term "includes" and tautological equivalents thereof, means the inclusion of the stated features, steps, operations, and / or components but not to the exclusion 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 one of ordinary skill in the art, unless otherwise defined. It should be further borne in mind that the

[0021] In the case of using expressions similar to "at least one of A, B, and C", etc., it is generally intended to include each and every combination of A, B, and C, as well as the possibility that only one of A, B, and C is used, unless otherwise defined or intended by context (e.g., "a system having at least one of A, B, and C" is intended to cover a system having A alone, a system having B alone, a system having C alone, a system having A and B together, a system having A and C together, a system having B and C together, and a system having A, B, and C together, etc.).

[0022] Due to some devices electrically connected with the circuit board, when the ground level fluctuates greatly, the signal will be distorted, or the level remains unstable to cause system misoperation. Therefore, the ground bounce noise needs to be processed to ensure the accuracy of the signal in the system and the stability of the system.

[0023] The circuit board can include multiple grounding regions with different noise tolerance. For example, the circuit board can include a first grounding region and a second grounding region, and the reference level fluctuation tolerance of the second grounding region is greater than that of the first grounding region. In the following, the first grounding region can also be referred to as "sensitive ground", and the second grounding region can also be referred to as "noise ground". In an embodiment, a single capacitor can be connected in series between the noise ground and the sensitive ground. But the single capacitor scheme can bypass high-frequency noise, but lacks transient overvoltage protection capability, and is easy to be broken by ESD (Electro-Static Discharge). In addition, the single TVS diode (Transient Voltage Suppressor Diode) scheme causes the high-frequency ground plane to be short-circuited due to the excessive junction capacitance (> 5pF), and the isolation degree is degraded by more than 20dB@1GHz. Especially in high-reliability scenarios such as automotive electronics and SerDes (Serializer / Deserializer) interfaces, the above-mentioned embodiments are difficult to meet the three requirements of DC isolation, high-frequency noise suppression and transient protection at the same time.

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

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

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

[0027] The capacitor C and the diode D are connected in series between a first ground region G1 and a second ground region G2 of a circuit board. In the present application, the capacitor C and the diode D are connected in series, and the specific arrangement position is not limited. For example, in the example shown, the positions of the capacitor C and the diode D can be exchanged. Figure 1A

[0028] The forward conduction path of the diode D (i.e., the path from the anode end to the cathode end) 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 a ground level end to which a device causing a relatively large reference level fluctuation on the circuit board is connected. The first ground region G1 can be a ground level end to which a device requiring a relatively small reference level fluctuation on the circuit board is connected. Here, the first ground region G1 and the second ground region G2 can both be designed to provide a "ground" reference level for the corresponding device.

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

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

[0032] The line width of the connection line between the capacitor C and the diode D can be greater than 10 mils. The capacitor C and the diode D can be located on the top surface or the bottom surface of the circuit board. The second ground region G2 and the first ground region G1 can be single-point connected to the metal shell of the electronic device to which the circuit board is electrically connected, wherein the metal shell is connected to the ground.

[0033] According to the embodiment of the present application, the line width of the connection line between the capacitor C and the diode D is greater than 10 mils, avoiding the influence of the parasitic inductance formed by the connection line on the function of the capacitor C, such as the function of passing high-frequency noise.

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

[0035] In the case that the second ground region G2 and the series connection of the capacitor C and the diode D are located on different layers of the circuit board, the second ground region G2 and the series connection of the capacitor C and the diode D are connected through a via hole on the circuit board, which is referred to as via hole connection. In the case that the first ground region G1 and the series connection of the capacitor C and the diode D are located on different layers of the circuit board, the first ground region G1 and the series connection of the capacitor C and the diode D are connected through a via hole.

[0036] According to embodiments of the present application, a device on the circuit board that causes relatively large reference level fluctuation can be electrically connected to the second ground region G2, so as to provide the ground reference level to the device from the second ground region G2. On the other hand, the device can introduce relatively large reference level fluctuation to the second ground region G2, causing ground bounce noise.

[0037] For example, the device on the circuit board that causes relatively large reference level fluctuation can be a crystal oscillator or a DC-DC converter, etc.

[0038] According to embodiments of the present application, a device on the circuit board that requires relatively small reference level fluctuation can be electrically connected to the first ground region G1, so as to provide the ground reference level to the device from the first ground region G1. It is desired that the reference level fluctuation provided by the first ground region G1 does not affect the device on the circuit board that requires relatively small reference level fluctuation, and the signal of the device is not distorted, nor does the system malfunction due to unstable level keeping.

[0039] For example, the device on the circuit board that requires relatively small reference level fluctuation can 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, etc.

[0040] For example, in the case that a device A requiring a relatively small reference level fluctuation on a circuit board is provided with a clock signal by a crystal oscillator electrically connected to a second ground area, and the device A requiring a relatively small reference level fluctuation is electrically connected to a first ground area G1, the ground bounce noise suppression circuit provided by the embodiment of the present application can be connected in series between the first ground area G1 and the second ground area G2. Since the ground bounce noise suppression circuit provided by the embodiment of the present application includes a capacitor C and a diode D, the capacitor C and the diode D are connected in series between the first ground area G1 and the second ground area G2 of the circuit board, and the forward conduction path of the diode D corresponds to the direction from the first ground area G1 to the second ground area G2, a return path can be formed between the first ground area G1 and the second ground area G2 by the capacitor C and the diode D. At the same time, the influence of the ground bounce noise at the second ground area G2 on the reference level of the first ground area G1 can be reduced or even avoided.

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

[0042] According to the embodiment of the present application, the main role of the capacitor C is to provide a low-impedance return path for high-frequency ground bounce noise, limit the high-frequency ground bounce noise current in a local loop, reduce its influence on other circuits (i.e., achieve high-frequency "bridging"), and at the same time, isolate the direct current signal in the ground bounce noise from the first ground area G1. At the same time, the capacitor C blocks direct current and low-frequency level differences. In the case that medium and high-frequency noise is coupled to the first ground area G1, at this time, the noise return path can be greatly reduced by the capacitor C and the forward diode D to return to the second ground area G2, and the loop radiation is reduced.

[0043] According to the embodiment of the present application, the main role of the one-way diode D is to clamp the large medium-frequency noise that may occur between the first ground area G1 and the second ground area G2, on the basis of ensuring the return of high-frequency signals, to suppress the medium-frequency voltage that may exist in the second ground area G2, to reduce the voltage fluctuation of the first ground area G1, and to protect the reference level of the sensitive signal. In addition, the reverse junction capacitor of the diode D can be used to construct a high-frequency path to bypass the high-frequency noise current to the chassis ground. Here, the chassis ground can be a reference ground formed by connecting the metal shell of an electronic device electrically connected to the circuit board to the ground.

[0044] According to the embodiment of the present application, the ground bounce noise suppression circuit includes a capacitor and a diode connected in series between the first ground region and the second ground region 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. The direct current signal between the second ground region and the first ground region can be isolated by the capacitor. In addition, by using the capacitor and the diode, the high-frequency ground bounce noise current can be limited in the local loop formed by the second ground region, the capacitor, the diode and the first ground region, and the influence on other circuits is reduced. In addition, the first ground region can be protected from the transient overvoltage caused by the ground bounce noise by using the diode. According to the embodiment of the present application, the direct current isolation, the high-frequency noise suppression and the transient protection of the first ground region are realized, the influence of the ground bounce noise on the first ground region is greatly reduced, and the signal accuracy in the system and the system stability are ensured.

[0045] According to the embodiment of the present application, since the capacitor and the diode included in the ground bounce noise suppression circuit are connected in series between the first ground region and the second ground region 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, the device that causes relatively large reference level fluctuation on the circuit board and the device that requires relatively small reference level fluctuation on the circuit board are electrically connected, and the device that causes relatively large reference level fluctuation on the circuit board is electrically connected to the second ground region, and the device that requires relatively small reference level fluctuation on the circuit board is electrically connected to the first ground region, and the capacitor and the diode form a reflux path between the first ground region and the second ground region. At the same time, the influence of the ground bounce noise at the second ground region on the reference level of the first ground region can be avoided.

[0046] According to the ground bounce noise suppression circuit provided by the embodiment of the present application, by placing the combination of the one-way diode and the capacitor between the second ground region G2 and the first ground region G1, the influence of the ground bounce noise on the first ground region G1 is prevented.

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

[0048] According to the embodiment of the present application, since the ground bounce noise suppression circuit comprises the capacitor C, the first end of the capacitor C is electrically connected with the first ground region G1, the second end of the capacitor C is electrically connected with the anode end of the diode D, the cathode end of the diode D is electrically connected with the second ground region G2, which ensures that the capacitor and the diode are connected in series between the first ground region and the second ground region 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. Furthermore, the direct current signal between the second ground region G2 and the first ground region G1 can be isolated by the capacitor C; at the same time, the high-frequency ground bounce noise current can be limited in the local loop formed by the second ground region G2, the capacitor C, the diode D and the first ground region G1 by the capacitor C and the diode D, so as to reduce the influence on other circuits; at the same time, the diode D can protect the first ground region G1 from the instantaneous overvoltage caused by the ground bounce noise. Therefore, the direct current isolation, high-frequency noise suppression and transient protection of the first ground region G1 can be realized, the influence of the ground bounce noise on the first ground region G1 is greatly reduced, and the signal accuracy in the system and the system stability are ensured.

[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] As shown in Figure 1B , the ground bounce noise suppression circuit comprises a capacitor C, a diode D and a bleeder resistor R connected in parallel with the diode D. The capacitor C and the diode D are connected in series 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.

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

[0052] According to the embodiment of the present application, the bleeder resistor R is connected in parallel across the diode D, so as to avoid the charge accumulation from breaking the diode D. The 1MΩ bleeder resistor R can ensure that the charges accumulated on both sides of the diode D are released slowly, which will not affect the reference level of the sensitive signal, i.e. the reference level of the first ground region G1, and at the same time, it can also ensure that there is no long-term level difference between the two sides of the diode D to cause damage to the diode D. Here, the sensitive signal can be a signal transmitted by a device on the circuit board which requires a relatively small reference level fluctuation.

[0053] Figure 2 A schematic circuit diagram of a ground bounce noise suppression circuit according to a third embodiment of the present application is shown.

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

[0055] In an initial state, the capacitor C can be connected in series with any one of the diodes D between the first ground region G1 and the second ground region G2 of the circuit board. The forward conduction path of any one of the diodes 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.

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

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

[0058] The control module can be configured to control the plurality of first switches K1 according to the reference level acquired by the signal acquisition 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. A micro-voltage sensor (such as a differential detection circuit based on an operational amplifier) can be integrated in a critical area of the circuit board (such as near a high-speed chip pin, at a power / ground plane junction), to acquire the reference level of the second ground region G2 in real time, and then use the control module to obtain the voltage amplitude and frequency characteristics of the ground bounce noise.

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

[0061] According to the embodiments of the present application, by acquiring the reference level of the second ground region by using the signal acquisition module, and then controlling the plurality of first switches according to the reference level acquired by the signal acquisition module by using the control module, a target diode suitable for suppressing ground bounce noise can be automatically adjusted, the target diode among the plurality of diodes D is connected in series between the first ground region and the second ground region, and a better ground bounce noise suppression function is provided.

[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 the embodiments of the present application, in the case that the noise frequency is less than 200MHz and the number of the reference levels greater than 50V is greater than or equal to 2, it indicates that there is ESD in the second ground region G2 and there is a large voltage fluctuation. At this time, the ground bounce noise suppression circuit can use the Schottky diode.

[0071] According to the embodiments of the present application, in the case that the noise frequency is greater than or equal to 200MHz, it indicates that the ground bounce noise frequency in the second ground region G2 changes rapidly and there can also be a large voltage fluctuation. At this time, the ground bounce noise suppression circuit can use the TSV diode.

[0072] According to the embodiments of the present application, by using the control module to determine the noise frequency according to the plurality of reference levels collected in the predetermined period, based on the noise frequency being less than the predetermined frequency and the number of the reference levels greater than the predetermined voltage being less than the predetermined number, the first switch electrically connected with the first diode is controlled to be closed and the first switch electrically connected with the other diode is controlled to be opened; based on the noise frequency being less than the predetermined frequency and the number of the reference levels greater than the predetermined voltage being greater than or equal to the predetermined number, the first switch electrically connected with the second diode is controlled to be closed and the first switch electrically connected with the other diode is controlled to be opened; based on the noise frequency being greater than or equal to the predetermined frequency, the first switch electrically connected with the third diode is controlled to be closed and the first switch electrically connected with the other diode is controlled to be opened, the optimal diode for suppressing the ground bounce noise can be automatically selected from the conventional diode, the Schottky diode and the TSV diode, so as to connect the target diode in the plurality of diodes in series between the first ground region and the second ground region, and a better ground bounce noise suppression function is provided.

[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] As shown in Figure 3 The ground bounce noise suppression circuit can include a plurality of capacitors C, diodes D, a signal acquisition module, a control module and a plurality of second switches K2 electrically connected with the plurality of capacitors C respectively. The plurality of capacitors C have different capacitance values.

[0075] In the initial state, the diode D can be connected in series between the first ground region G1 and the second ground region G2 of the circuit board with any one of the capacitors C. 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 capacitor C can have a capacitance value of 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 connection of each capacitor C and the corresponding second switch K2 is connected in parallel with each other.

[0077] The signal acquisition module is electrically connected to the device electrically connected to the first ground region G1 on the circuit board. 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 the identification information of the device. The control module is configured to determine the signal frequency of the signal transmitted by the device according to the identification information of the device, and control the plurality of second switches K2 according to the signal frequency, so as to connect the target capacitor in the plurality of capacitors in series between the first ground region and the second ground region.

[0079] According to the embodiments of the present application, by acquiring the identification information of the device by the signal acquisition module, determining the signal frequency of the signal transmitted by the device according to the identification information of the device by the control module, and controlling the plurality of second switches according to the signal frequency, the optimal target capacitor can be automatically selected from the plurality of capacitors with different capacitance values, and the target capacitor is used to turn on the backflow path between the first ground region and the second ground region.

[0080] Figure 4 A schematic circuit diagram of the geophone noise suppression circuit according to the fifth embodiment of the present application is shown.

[0081] As shown in Figure 4 , the geophone noise suppression circuit can 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 respectively, a signal acquisition module, a control module, and a plurality of second switches K2 electrically connected to the plurality of capacitors C respectively. The plurality of capacitors C have different capacitance values. Figure 4 The diodes D and the first switches K1 in Figure 2 have similar structures and functions, and for the sake of simplicity, will not be described here.

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

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

[0084] Figure 4 The control module in Figure 2The control module is further electrically connected with a plurality of second switches K2. The control module is further configured to: determine a signal frequency of a signal transmitted by the device according to the identification information of the device; and control the plurality of second switches K2 according to the signal frequency, so as to connect a target capacitor in the plurality of capacitors in series between the first grounding area G1 and the second grounding area G2.

[0085] In Figure 4 In the embodiment, the second grounding area G2 and the first grounding area G1 are both single-point connected to a case ground G3. The case ground G3 is a reference ground formed after a metal shell of an electronic device electrically connected with the circuit board is connected with the ground.

[0086] According to the embodiment of the present application, for any device electrically connected to the first grounding area G1, a signal transmitted by the device has a certain signal frequency. Therefore, the signal frequency of the signal transmitted by the device capable of being electrically connected to the first grounding area G1 can be pre-configured in the control module. After the identification information of the device is collected by the signal collection module, the control module can determine a capacitor corresponding to the signal frequency according to the pre-configured corresponding signal frequency, and then control the second switch K2 corresponding to the capacitor.

[0087] For example, the signal collection module can also be electrically connected with a plurality of devices on the circuit board electrically connected to the first grounding area G1, and the control module can also determine signal frequencies of signals transmitted by the plurality of devices according to identification information of the plurality of devices, and control the plurality of second switches K2 according to the plurality of signal frequencies, so as to connect a target capacitor in the plurality of capacitors in series between the first grounding area and the second grounding area, thereby enabling the plurality of devices to form a backflow path between the first grounding area and the second grounding area. The plurality of devices can be each device electrically connected to the first grounding area G1. The plurality of devices can also be each device electrically connected to the first grounding area G1 and a device causing relatively large reference level fluctuation on the circuit board. Here, the device causing relatively large reference level fluctuation on the circuit board is electrically connected with the second grounding area G2.

[0088] According to the embodiment of the present application, by collecting the identification information of the device by the signal collection module, and determining the signal frequency of the signal transmitted by the device according to the identification information of the device by the control module, and controlling the plurality of second switches according to the signal frequency, the optimal target capacitor can be automatically selected from the plurality of capacitors with different capacitance values, and the backflow path between the first grounding area and the second grounding area is turned on by the target capacitor.

[0089] According to the embodiment 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 with a first connection point A1 on the first connection region and a first connection point B1 on the second connection region. Another series pair of a capacitor C and a diode D is electrically connected with a second connection point A2 on the first connection region and a second connection point B2 on the second connection region. Still another series pair of a capacitor C and a diode D is electrically connected with a third connection point A3 on the first connection region and a third connection point B3 on the second connection region. The first connection point A1 on the first connection region is adjacent to the second connection point A2 on the first connection region in the first direction. The second connection point A2 on the first connection region is adjacent to the third connection point A3 on the first connection region in the first direction. The first connection point B1 on the second connection region is adjacent to the second connection point B2 on the second connection region in the first direction. The second connection point B2 on the second connection region is adjacent to the third connection point B3 on the second connection region in the first direction.

[0098] The interval L between A1 and A2 is less than or equal to 5 cm. The interval L between A2 and A3 is less than or equal to 5 cm. The interval L between B1 and B2 is less than or equal to 5 cm. The interval 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 geophone noise suppression circuit shown can further include a signal acquisition module, a control module, and a plurality of first switches K1 and a plurality of second switches K2 respectively arranged at the positions of the connection points in the first direction. Figure 4 The plurality of capacitors C, the plurality of diodes D, the plurality of first switches K1 electrically connected with the plurality of diodes D, and the plurality of second switches K2 electrically connected with the plurality of capacitors C shown can have the structure and function of the signal acquisition module, which will not be described here again. The control module can be electrically connected with the plurality of first switches K1 and the plurality of second switches K2 at the positions of the connection points on the basis of the signal acquisition module, and simultaneously control the plurality of first switches K1 and the plurality of second switches K2 at the positions of the connection points, so as to respectively electrically connect the series pairs of the plurality of target diodes and target capacitors to the first connection region and the second connection region via the corresponding connection points. Figure 4 The structure and function of the signal acquisition module shown will not be described here again. The control module can be electrically connected with the plurality of first switches K1 and the plurality of second switches K2 at the positions of the connection points on the basis of the signal acquisition module, and simultaneously control the plurality of first switches K1 and the plurality of second switches K2 at the positions of the connection points, so as to respectively electrically connect the series pairs of the plurality of target diodes and target capacitors to the first connection region and the second connection region via the corresponding connection points. Figure 4 The structure and function of the signal acquisition module shown will not be described here again. The control module can be electrically connected with the plurality of first switches K1 and the plurality of second switches K2 at the positions of the connection points on the basis of the signal acquisition module, and simultaneously control the plurality of first switches K1 and the plurality of second switches K2 at the positions of the connection points, so as to respectively electrically connect the series pairs of the plurality of target diodes and target capacitors to the first connection region and the second connection region via the corresponding connection points.

[0100] According to an embodiment of the present application, in the case that the lengths of the first ground region and the second ground region in the first direction are greater than the predetermined length, the ground bounce noise suppression circuit includes a plurality of series pairs of capacitors and diodes, each of the series pairs of capacitors C and diodes D is electrically connected to the first ground region and the second ground region via a corresponding connection point, the spacing between the connection points adjacent in the first direction is less than or equal to the predetermined length, the first direction is perpendicular to the second direction, the first ground region and the second ground region are spaced apart in the second direction, which can avoid the signal return path being too long and speed up the signal return speed in the case that the areas of the two ground regions are relatively large and the signals involved are relatively large.

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

[0102] As shown in Figure 6 , the circuit board includes a second ground region and a first ground region and a ground bounce noise suppression circuit. The reference level fluctuation tolerance of the second ground region is greater than that of the first ground region. The projections of the first ground region and the second ground region in the thickness direction of the circuit board do not overlap. The ground bounce noise suppression circuit can include capacitors C and diodes D. The ground bounce noise suppression circuit can be any of the above ground bounce noise suppression circuits, which will not be described here for simplicity.

[0103] According to an embodiment of the present application, the spacing between the second ground region and the first ground region is greater than 40 mils.

[0104] According to an embodiment of the present application, the copper spacing between the second ground region and the first ground region is greater than 40 mils, which avoids direct interference coupling between the second ground region and the first ground region.

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

[0106] As shown in Figure 7 , the circuit board includes a second ground region and a first ground region and a ground bounce noise suppression circuit. Here, the reference level fluctuation tolerance of the second ground region is greater than that of the first ground region. The projections of the first ground region and the second ground region in the thickness direction of the circuit board do not overlap. Here, the ground bounce noise suppression circuit can include capacitors C and diodes D. The ground bounce noise suppression circuit can be any of the above ground bounce noise suppression circuits, which will not be described here for simplicity.

[0107] The second ground region and the first ground region are connected to the 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 shell through screw holes on the circuit board or other means. Meanwhile, a sufficient number of grounding holes can be provided on the circuit board to discharge the interference level generated by the second grounding area through a minimum impedance path. A grounding resistance less than 0.1 Ω can be taken as a measure of whether the grounding is strong enough. The grounding resistance is the resistance between the second grounding area and the metal shell and the resistance between the first grounding area and the metal shell. When the grounding resistance is less than 0.1 Ω, it indicates that the grounding is strong enough.

[0109] According to an embodiment of the present application, Figure 7 The circuit board shown can provide a low-impedance return path for high-frequency ground bounce noise, limit the high-frequency ground bounce noise current in a local loop, and reduce its impact on other circuits (i.e., achieve high-frequency "bridging"). The high-frequency ground bounce noise can flow from the second grounding area to the chassis ground via the capacitor C and the diode D and the first grounding area. Since the voltage fluctuation caused by the high-frequency ground bounce noise is small, even if the high-frequency ground bounce noise is discharged via the first grounding area, it will not affect the reference level of the first grounding area. Here, the chassis ground can be a reference ground formed after the metal shell of the electronic device electrically connected to the circuit board is connected to the ground.

[0110] Meanwhile Figure 7 The circuit board shown can, in the case of medium-high frequency noise coupling to the first grounding area, return to the second grounding area through the capacitor C and the forward diode D, greatly reduce the noise return path, and reduce loop radiation.

[0111] Meanwhile, in the case where devices requiring a relatively small reference voltage fluctuation on the circuit board, devices electrically connected to the first grounding area and the circuit board causing a relatively large reference level fluctuation, and devices causing a relatively large reference level fluctuation on the circuit board are electrically connected to the second grounding area, a return path can be formed between the first grounding area and the second grounding 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 single-point connected to the metal shell of the electronic device electrically connected to the circuit board, the metal shell is connected to the ground, and high-frequency noise can be discharged through the reference ground formed after the metal shell of the electronic device electrically connected to the circuit board is connected to the ground, avoiding the interference of the high-frequency noise coupled to the internal signals of the circuit board.

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

[0114] Figure 8 A flowchart of a ground bounce noise suppression method according to an embodiment of the present application is shown.

[0115] AsFigure 8 As shown, the ground bounce noise suppression method can include operation S810 to operation S820. Here, Figure 8 The ground bounce noise suppression method as shown can be applied to the ground bounce noise suppression circuit described above.

[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 backflow path is formed between the first ground region and a second ground region by a capacitor and a diode.

[0118] According to an embodiment of the present application, the ground bounce noise suppression method can further include: in a case where a device requiring a relatively small reference voltage fluctuation on a circuit board, a device electrically connected to the first ground region and causing a relatively large reference level fluctuation on the circuit board, and the device causing the relatively large reference level fluctuation on the circuit board are electrically connected to the second ground region, forming a backflow path between the first ground region and the second ground region by a capacitor and a diode.

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

[0120] It should be noted that the ground bounce noise suppression method part in the embodiments of the present application corresponds to the ground bounce noise suppression circuit part in the embodiments of the present application, and the description of the ground bounce noise suppression method part is specifically referred to the ground bounce noise suppression circuit part, which will not be described here.

[0121] Those skilled in the art can understand that the features described in various embodiments of the present application can be combined and / or integrated in various combinations, even if such combinations or integrations are not explicitly described in the present application. In particular, the features described in various embodiments of the present application can be combined and / or integrated in various combinations without departing from the spirit and teachings of the present application. All these combinations and / or integrations fall within the scope of the present application.

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

Claims

1. A geophone noise rejection circuit, characterized by, The ground bounce noise suppression circuit comprises: a capacitor and a diode connected in series between a first land region and a second land region of a circuit board; a bleeder resistor connected in parallel with the diode; wherein a forward conduction path of the diode corresponds to a direction from the first land region to the second land region; wherein a reference level fluctuation tolerance of the second land region is greater than a reference level fluctuation tolerance of the first land region, and projections of the first land region and the second land region along a thickness direction of the circuit board do not overlap.

2. The geophone noise rejection circuit of claim 1, wherein, A first end of the capacitor is electrically connected to the first land 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 land region.

3. The geophone noise rejection circuit of claim 1, wherein, The diode is a plurality of diodes; The ground bounce noise suppression circuit further comprises: a plurality of first switches electrically connected to the plurality of diodes respectively, each of the diodes is connected in series with a corresponding first switch, and each of the diodes and the corresponding first switch are connected in parallel with each other; a signal acquisition module electrically connected to the second land region and configured to acquire a reference level of the second land region; a control module electrically connected to the plurality of first switches and the signal acquisition module and configured to control the plurality of first switches according to the reference level acquired by the signal acquisition module to connect a target diode in the plurality of diodes in series between the first land region and the second land region.

4. The geophone noise rejection circuit of claim 3, wherein, The plurality of diodes comprises a first diode, a second diode, and a third diode. The control module is further configured to: determine a noise frequency according to a plurality of reference levels acquired within a predetermined period; based on the noise frequency being less than a predetermined frequency and a number of the plurality of reference levels being greater than a predetermined voltage being less than a predetermined number, control a first switch electrically connected to the first diode to be closed and control first switches electrically connected to other diodes to be opened; based on the noise frequency being less than the predetermined frequency and the number of the plurality of reference levels being greater than the predetermined voltage being greater than or equal to the predetermined number, control a first switch electrically connected to the second diode to be closed and control first switches electrically connected to other diodes to be opened; based on the noise frequency being greater than or equal to the predetermined frequency, control a first switch electrically connected to the third diode to be closed and control first switches electrically connected to other diodes to be opened.

5. The geophone noise rejection circuit of claim 4, wherein, The first diode is a conventional diode, the second diode is a Schottky diode, and the third diode is a TSV diode.

6. The geophone noise rejection circuit of claim 3, wherein, The capacitor is a plurality of capacitors, and the plurality of capacitors have different capacitance values; The ground bounce noise suppression circuit further comprises: a plurality of second switches electrically connected to the plurality of capacitors respectively, each of the capacitors is connected in series with a corresponding second switch, and each of the capacitors and the corresponding second switch are connected in parallel with each other; the signal acquisition module is electrically connected to a device on the circuit board and electrically connected to the first land region, 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: According to the identification information of the device, a signal frequency of a signal transmitted by the device is determined; According to the signal frequency, the plurality of second switches are controlled so as to connect a target capacitor in the plurality of capacitors in series between the first land region and the second land region.

7. The geophone noise rejection circuit of claim 1, wherein, A line width of a connection line between the capacitor and the diode is greater than 10 mils; The capacitor and the diode are located on a top surface or a bottom surface of the circuit board.

8. The geophone noise rejection circuit of claim 1, wherein, In a case where a length of the first land region and the second land region in a 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 land region and the second land region via respective connection points, a pitch between adjacent connection points in the first direction is less than or equal to the predetermined length, the first direction is perpendicular to a second direction, and the first land region and the second land region are spaced apart in the second direction.

9. A circuit board, characterized by A circuit board includes a first land region and a second land region and the ground bounce noise suppression circuit of any one of claims 1-8, wherein a reference level fluctuation tolerance of the second land region is greater than a reference level fluctuation tolerance of the first land region, and projections of the first land region and the second land region in a thickness direction of the circuit board do not overlap.

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