Power supply filter circuit and power supply filter device

Abstract

The utility model provides a power supply filter circuit and a power supply filter device. The power supply filter circuit comprises a power supply input end, a load power supply output end, an anti-reverse connection circuit, a plurality of inductance units and a plurality of capacitor units, wherein the anti-reverse-connection circuit is connected between the power supply input end and a path of the load power supply output end; the plurality of inductor units and the plurality of capacitor units are connected between the paths of the power supply input end and the load power supply output end to form N filtering sub-circuits; wherein N is a positive integer greater than or equal to 1. Specifically, N filtering sub-circuits are formed between paths of a power supply input end and a load power supply output end, so that the problem of electromagnetic interference between front-end equipment and rear-end equipment of the power supply filtering circuit can be inhibited and even eliminated, and an anti-reverse-connection circuit is arranged between the paths of the power supply input end and the load power supply output end. The power filter circuit can be effectively prevented from being damaged under the condition of reverse connection of positive and negative electrodes of the power supply.

Description

Technical Field

[0001] This application relates to the field of power filtering technology, and in particular to a power filtering circuit and a power filtering device. Background Technology

[0002] With societal development, the types and number of functional modules within automobiles are increasing daily. This poses a growing challenge to automotive amplifier systems powered by onboard batteries, leading to increasingly severe electromagnetic interference from the power supply. If this interference noise is not effectively filtered out, it can significantly impact the automotive amplifier system, ranging from reducing the signal-to-noise ratio to damaging internal chips and causing complete silence. Simultaneously, if electromagnetic interference signals generated by the internal circuitry of the automotive amplifier system are not properly filtered out, they can also significantly interfere with the vehicle's power supply and affect other automotive components, potentially causing damage.

[0003] Therefore, it is necessary to design a power supply filtering circuit to improve the electromagnetic interference between the power supply and the vehicle power amplifier system. Utility Model Content

[0004] To address the aforementioned problems, this application provides a power filtering circuit and a power filtering device that can resolve the electromagnetic interference between the power supply and the vehicle power amplifier system.

[0005] To address the aforementioned problems, the first technical solution provided in this application is: a power supply filtering circuit, comprising:

[0006] Power input terminal and load power output terminal;

[0007] A reverse connection protection circuit is connected between the load power output terminal and the path of the load power output terminal.

[0008] Multiple inductor units and multiple capacitor units are connected between the load power supply output terminal and the path of the load power supply output terminal to form N filter sub-circuits; where N is a positive integer greater than or equal to 1.

[0009] In some embodiments, the reverse connection protection circuit includes a diode, the anode of which is connected to the power input terminal, and the cathode of which is connected to the filter sub-circuit.

[0010] In some embodiments, the reverse connection protection circuit includes a first diode and a second diode; the anodes of the first diode and the second diode are connected to a first node, and the cathodes of the first diode and the second diode are connected to a second node.

[0011] In some embodiments, the power supply filtering circuit further includes:

[0012] A surge protection circuit is connected between the power input terminal and the ground voltage.

[0013] In some embodiments, the surge protection circuit includes a third diode, the cathode of which is connected to the power input terminal, and the anode of which is grounded.

[0014] In some embodiments, between the load power output terminal and the path of the load power output terminal, there are a first capacitor unit, a first inductor unit, a second capacitor unit and a third capacitor unit connected in sequence.

[0015] Wherein, the first inductor unit and the second capacitor unit form a first filter sub-circuit; the first inductor unit and the third capacitor unit form a second filter sub-circuit; and the first inductor unit and the first capacitor unit form a third filter sub-circuit.

[0016] In some embodiments, a second inductor unit and a fourth capacitor unit are further connected in sequence between the third capacitor unit and the load power supply output terminal.

[0017] The second inductor unit and the fourth capacitor unit form a fourth filter sub-circuit; the second inductor unit and the third capacitor unit form a fifth filter sub-circuit.

[0018] In some embodiments, the second capacitor unit, the third capacitor unit, and / or the fourth capacitor unit include multiple capacitor branches connected in parallel, and each capacitor branch includes a capacitor.

[0019] In some embodiments, each of the capacitor branches includes two capacitors connected in series.

[0020] To solve the above problems, the second technical solution provided by this application is: to provide a power filtering device, wherein the power filtering device includes the power filtering circuit described in any one of the above claims.

[0021] The beneficial effects of this application are that, unlike the prior art, the power filtering circuit and power filtering device provided in this application include a power input terminal, a load power output terminal, a reverse connection protection circuit, multiple inductor units, and multiple capacitor units. The reverse connection protection circuit is connected between the power input terminal and the load power output terminal. The multiple inductor units and multiple capacitor units are connected between the power input terminal and the load power output terminal, forming N filter sub-circuits, where N is a positive integer greater than or equal to 1. Specifically, by forming N filter sub-circuits between the power input terminal and the load power output terminal, electromagnetic interference between the upstream and downstream devices of the power filtering circuit can be suppressed or even eliminated. Furthermore, by setting a reverse connection protection circuit between the power input terminal and the load power output terminal, damage to the power filtering circuit can be effectively prevented when the positive and negative terminals of the power supply are reversed. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0023] Figure 1 A schematic diagram of a module of an embodiment of the power filtering circuit provided in this application;

[0024] Figure 2 A schematic diagram of another embodiment of the power filtering circuit provided in this application;

[0025] Figure 3 A circuit diagram of one embodiment of the power filtering circuit provided in this application;

[0026] Figure 4 A schematic diagram of a module for yet another embodiment of the power filtering circuit provided in this application;

[0027] Figure 5 A circuit diagram of another embodiment of the power filtering circuit provided in this application;

[0028] Figure 6 This is a schematic diagram of a module of an embodiment of the power filtering device provided in this application.

[0029] Label Explanation:

[0030] Power input terminal - U1;

[0031] Load power supply output terminal -V1;

[0032] Reverse polarity protection circuit -10; First diode -D1; Second diode -D2;

[0033] First inductor unit-21; Second inductor unit-22;

[0034] First capacitor unit-31, second capacitor unit-32; third capacitor unit-33; fourth capacitor unit-34;

[0035] Surge protection circuit -50; Third diode D3;

[0036] Power supply filtering circuit -100; Power supply filtering device -1000. Detailed Implementation

[0037] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0038] The terms "first," "second," and "third" in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0039] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0041] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0042] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0043] See Figure 1 , Figure 1 This is a schematic diagram of a module of an embodiment of the power filtering circuit provided in this application. This application provides a power filtering circuit including a power input terminal U1, a load power output terminal V1, a reverse connection protection circuit 10, multiple inductor units (specific reference numerals are given below), and multiple capacitor units (specific reference numerals are given below); wherein, the reverse connection protection circuit 10 is connected between the power input terminal U1 and the load power output terminal V1; the multiple inductor units and the multiple capacitor units are connected between the power input terminal U1 and the load power output terminal V1, forming N filter sub-circuits; wherein, N is a positive integer greater than or equal to 1.

[0044] Specifically, by forming N filter sub-circuits between the power input terminal U1 and the load power output terminal V1, electromagnetic interference between the front and back end devices of the power filter circuit can be suppressed or even eliminated; and by setting a reverse connection protection circuit 10 between the power input terminal U1 and the load power output terminal V1, the power filter circuit can be effectively prevented from being damaged in the event of reverse connection of the positive and negative poles of the power supply.

[0045] In some embodiments, the reverse connection protection circuit 10 may include electrical components such as diodes, field-effect transistors, relays, or dedicated ICs, as long as they can prevent damage to the power supply filter circuit when the power supply and the power input terminal U1 are reversed.

[0046] The reverse connection protection circuit 10 includes a diode, with the anode of the diode connected to the power input terminal U1 and the cathode of the diode connected to the filter sub-circuit.

[0047] Specifically, in the case of reverse connection of the power supply positive and negative terminals, due to the unidirectional conduction of the diode, the diode is in an open circuit state, and will not burn out the DC power supply filter circuit and the components in the downstream load due to reverse connection, thus playing a protective role.

[0048] See Figure 2 , Figure 2 This is a schematic diagram of another embodiment of the power filtering circuit provided in this application. In one embodiment, the power filtering circuit further includes a surge protection circuit 50, which is connected between the power input terminal U1 and the ground voltage.

[0049] Specifically, the surge protection circuit 50 can protect the power filter circuit from voltage transients, thereby extending the life of the power filter circuit, ensuring stable system operation, and reducing maintenance costs.

[0050] In some embodiments, the surge protection circuit 50 may include a gas discharge tube, a varistor, a thermistor, or a diode (e.g., a transient voltage suppressor diode), etc., which are not limited here, and can be selected according to actual needs.

[0051] See Figure 3 , Figure 3 This is a circuit diagram of an embodiment of the power filtering circuit provided in this application. In this embodiment, the reverse connection protection circuit 10 includes a first diode D1 and a second diode D2; the anode of the first diode D1, the anode of the second diode D2, and the power input terminal U1 are connected to the first node n1, the cathode of the first diode D1 and the cathode of the second diode D2 are connected to the second node n2, and the second node n2 is also connected to a filter sub-circuit.

[0052] Specifically, the reverse connection protection circuit 10 includes two diodes connected in parallel, which can increase the current carrying capacity and improve the system reliability.

[0053] Please continue reading Figure 3 In this embodiment of the application, the surge protection circuit 50 includes a third diode D3, the cathode of the third diode D3 is connected to the power input terminal U1, and the anode of the third diode D3 is grounded.

[0054] Specifically, diodes can respond to voltage changes in a very short time and quickly conduct after exceeding their breakdown voltage, diverting surge current to ground. They have a very fast response time and a low clamping voltage.

[0055] Combination Figure 2 and Figure 3In one embodiment, between the power input terminal U1 and the load power output terminal V1, there are a first capacitor unit 31, a first inductor unit 21, a second capacitor unit 32 and a third capacitor unit 33 connected in sequence.

[0056] The first inductor unit 21 and the second capacitor unit 32 form a first filter sub-circuit; the first inductor unit 21 and the third capacitor unit 33 form a second filter sub-circuit; and the first inductor unit 21 and the first capacitor unit 31 form a third filter sub-circuit.

[0057] Specifically, the first filter sub-circuit formed by the first inductor unit 21 and the second capacitor unit 32 can rectify the AC ripple of the power supply to obtain a relatively stable DC voltage, thus playing the role of power rectification.

[0058] The second filter sub-circuit formed by the first inductor unit 21 and the third capacitor unit 33 can filter out externally injected EMI (Electromagnetic Interference) noise to obtain a relatively pure DC voltage.

[0059] The third filter sub-circuit formed by the first inductor unit 21 and the first capacitor unit 31 can filter out internally diffused EMI noise to avoid EMI interference to the outside, thereby preventing EMI generated in the power supply filter circuit from interfering with other devices.

[0060] See Figure 4 and Figure 5 , Figure 4 A schematic diagram of a module for yet another embodiment of the power filtering circuit provided in this application; Figure 5 This is a circuit diagram of another embodiment of the power supply filtering circuit provided in this application. In one embodiment, a second inductor unit 22 and a fourth capacitor unit 34 are connected in sequence between the third capacitor unit 33 and the load power supply output terminal V1; wherein the second inductor unit 22 and the fourth capacitor unit 34 form a fourth filter sub-circuit; and the second inductor unit 22 and the third capacitor unit 33 form a fifth filter sub-circuit.

[0061] Specifically, the second and fourth filter sub-circuits form a second-order filter, which can improve the filtering effect of externally injected EMI noise. Furthermore, by setting the parameter values ​​of each component in the second and fourth filter sub-circuits, the operating frequency band of the second-order filter can be ≥1MHz, thus achieving the EMI filtering function.

[0062] The third and fifth filter sub-circuits form a second-order filter, which can improve the filtering effect of internally diffused EMI noise. Furthermore, by setting the parameter values ​​of each component in the third and fifth filter sub-circuits, the operating frequency band of the second-order filter can be ≥1MHz, thus achieving the EMI filtering function.

[0063] In addition, by setting the parameter values ​​of each component in the first filter sub-circuit, the operating frequency band of the first filter sub-circuit can be made <1MHz.

[0064] Therefore, the power supply filtering circuit provided in this application can meet the requirements of filtering noise over a wider frequency band.

[0065] Please continue reading Figure 5 In some embodiments, the second capacitor unit 32, the third capacitor unit 33 and / or the fourth capacitor unit 34 include multiple capacitor branches connected in parallel, and each capacitor branch includes a capacitor.

[0066] For example, one of the capacitor units 32, 33, and 34 may include multiple capacitor branches connected in parallel; or, two of the capacitor units 32, 33, and 34 may include multiple capacitor branches connected in parallel; or, all three capacitor units may include multiple capacitor branches connected in parallel. No limitation is made here.

[0067] The number of parallel capacitor branches included in each capacitor unit can be two, three, four, etc., and is not limited here. The specific design depends on actual needs. In this embodiment, three parallel capacitor branches are used as an example for each capacitor unit.

[0068] Specifically, by including at least some capacitor units with multiple parallel capacitor branches, the filtering effect can be improved. Furthermore, by selecting capacitor branches with different capacitance values ​​connected in parallel, the resulting filter can exhibit good attenuation characteristics throughout the entire preset frequency range. For example, smaller capacitors have a better response to higher frequency signals, while larger capacitors can handle lower frequency fluctuations.

[0069] In one embodiment, each capacitor branch includes two capacitors connected in series. Specifically, including two capacitors in series in each capacitor branch can reduce cost and layout space while improving performance.

[0070] In addition, each capacitor branch is configured with two capacitors connected in series, which prevents a short circuit between the power supply and ground in the event of mechanical stress causing a capacitor to fail and short-circuit, effectively avoiding power amplifier failure.

[0071] In a specific embodiment of this application, such as Figure 5 As shown, the first inductor unit 21 includes inductor L1; the second inductor unit 22 includes a ferrite bead FB; the first capacitor unit 31 includes ceramic capacitors C1, C2, C3, C4, C5, and C6; the second capacitor unit 32 includes an electrolytic capacitor CP; the third capacitor unit 33 includes ceramic capacitors C7, C8, C9, C10, C11, and C12; and the fourth capacitor unit 34 includes ceramic capacitors C13, C14, C15, C16, C17, and C18.

[0072] In this circuit, inductor L1 and electrolytic capacitor CP form the first filter sub-circuit; inductor L1 and ceramic capacitors C7, C8, C9, C10, C11 and C12 form the second filter sub-circuit; inductor L1 and ceramic capacitors C1, C2, C3, C4, C5 and C6 form the third filter sub-circuit; ferrite bead FB and ceramic capacitors C13, C14, C15, C16, C17 and C18 form the fourth filter sub-circuit; and ferrite bead FB and ceramic capacitors C7, C8, C9, C10, C11 and C12 form the fifth filter sub-circuit.

[0073] Specifically, the power filtering circuit provided in this application has the following advantages:

[0074] 1. It can meet the filtering noise requirements of a wider frequency band;

[0075] 2. It can meet the requirements of reverse connection protection and surge protection power supply voltage;

[0076] 3. Avoid short circuits caused by mechanical stress.

[0077] See Figure 6 , Figure 6 This is a schematic diagram of a module of an embodiment of the power filtering device provided in this application. This application also provides a power filtering device 1000, which can be applied to the in-vehicle power amplifier system of an automobile, including but not limited to gasoline-powered vehicles and electric vehicles. Electric vehicles include pure electric vehicles and hybrid electric vehicles powered by electric energy.

[0078] The power filtering device 1000 includes a power filtering circuit 100, which may include the power filtering circuit provided in any of the above embodiments. This prevents externally injected EMI noise from reducing the signal-to-noise ratio of the vehicle amplifier system, causing damage to internal chips, and resulting in silence. Furthermore, the power filtering circuit can filter out EMI noise diffused within the vehicle amplifier system, thereby reducing or even eliminating its impact on or damage to other automotive components.

[0079] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A power supply filtering circuit, characterized in that, The power filter circuit is used in an in-vehicle power amplifier system, and the power filter circuit includes: Power input terminal and load power output terminal; A reverse connection protection circuit is connected between the load power output terminal and the path of the load power output terminal. Multiple inductor units and multiple capacitor units are connected between the load power supply output terminal and the path of the load power supply output terminal to form N filter sub-circuits; where N is a positive integer greater than 1; the N filter sub-circuits form at least a second-order filter; Among them, between the load power output terminal and the path of the load power output terminal, the plurality of inductor units and the plurality of capacitor units include a first capacitor unit, a first inductor unit, a second capacitor unit, a third capacitor unit, a second inductor unit and a fourth capacitor unit connected in sequence. Wherein, the first inductor unit and the second capacitor unit form a first filter sub-circuit; the first inductor unit and the third capacitor unit form a second filter sub-circuit; the first inductor unit and the first capacitor unit form a third filter sub-circuit; the second inductor unit and the fourth capacitor unit form a fourth filter sub-circuit; and the second inductor unit and the third capacitor unit form a fifth filter sub-circuit. Wherein, the second filter sub-circuit and the fourth filter sub-circuit form a second-order filter; the third filter sub-circuit and the fifth filter sub-circuit form a second-order filter; At least some of the capacitor units include multiple capacitor branches connected in parallel, and each capacitor branch includes two capacitors connected in series.

2. The power supply filtering circuit according to claim 1, characterized in that, The reverse connection protection circuit includes a diode, the anode of which is connected to the power input terminal, and the cathode of which is connected to the filter sub-circuit.

3. The power supply filtering circuit according to claim 2, characterized in that, The reverse connection protection circuit includes a first diode and a second diode; the anodes of the first diode and the second diode are connected to a first node, and the cathodes of the first diode and the second diode are connected to a second node.

4. The power supply filtering circuit according to claim 1, characterized in that, The power supply filtering circuit also includes: A surge protection circuit is connected between the power input terminal and the ground voltage.

5. The power supply filtering circuit according to claim 4, characterized in that, The surge protection circuit includes a third diode, the cathode of which is connected to the power input terminal, and the anode of which is grounded.

6. The power supply filtering circuit according to claim 1, characterized in that, The second capacitor unit, the third capacitor unit, and / or the fourth capacitor unit include multiple capacitor branches connected in parallel, and each capacitor branch includes a capacitor.

7. A power supply filtering device, characterized in that, The power filtering device includes the power filtering circuit described in any one of claims 1-6.

Images