Electromagnetic interference filter circuit and electronic equipment

Abstract

The embodiment of the invention provides an electromagnetic interference filter circuit and electronic equipment. The electromagnetic interference filter circuit comprises an alternating current power supply port, a first filter circuit, a rectifier circuit, a rectifier bridge circuit, a power switch chip, a first inductor, a follow current circuit, a suppression circuit, a direct current output port and a first ground wire, the alternating current power supply port, the first filter circuit, the rectifying circuit, the power switch chip, the first inductor and the direct current output port are sequentially connected, the first filter circuit is further connected with the rectifier bridge circuit, the power switch chip is further connected with one end of the follow current circuit, and the other end of the follow current circuit is connected with the direct current output port. The other end of the follow current circuit is also connected with the rectifier bridge circuit and the rectifier circuit; the suppression circuit is used for suppressing electromagnetic signal interference; the suppression circuit comprises at least one of a first inlet suppression circuit, a second inlet suppression circuit, a first source suppression circuit, a second source suppression circuit, a first outlet suppression circuit and a second outlet suppression circuit, and the stability of electromagnetic compatibility is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of circuits, and specifically relates to an electromagnetic interference filtering circuit and an electronic device. Background Art

[0002] Induction cookers are electrical cooking appliances that use electromagnetic induction for heating. During normal operation, induction cookers can generate electromagnetic interference through high-frequency current radiation, power circuit conduction, and harmonic generation, which may have varying degrees of impact on surrounding electronic equipment and the power grid environment.

[0003] At present, in order to suppress electromagnetic interference, it is necessary to add a common mode suppression circuit inside the induction cooker product. For example, a magnetic ring can be added to the power cord to suppress the internal interference source from radiating to the external space. The location of the magnetic ring needs to be kept away from the interference source to prevent the interference line from affecting the power cord in front of the magnetic ring. The location of the magnetic ring can occupy the space inside the product, or be fixed on the power cord outside the product.

[0004] In the above processing, the processing requirements of the magnetic ring are high, resulting in low stability of electromagnetic compatibility. Summary of the invention

[0005] The embodiments of the present application relate to an electromagnetic interference filtering circuit and an electronic device, which are used to solve the defect in the prior art that the processing requirements of the magnetic ring are high, resulting in low electromagnetic compatibility stability.

[0006] In a first aspect, an embodiment of the present application provides an electromagnetic interference filter circuit, the electromagnetic interference filter circuit comprising an AC power port, a first filter circuit, a rectifier circuit, a rectifier bridge circuit, a power switch chip, a first inductor, a freewheeling circuit, a suppression circuit, a DC output port and a first ground wire;

[0007] The AC power port, the first filter circuit, the rectifier circuit, the power switch chip, the first inductor, and the DC output port are connected in sequence, the first filter circuit is also connected to the rectifier bridge circuit, the power switch chip is also connected to one end of the freewheeling circuit, the other end of the freewheeling circuit is connected to the DC output port, and the other end of the freewheeling circuit is also connected to the rectifier bridge circuit and the rectifier circuit;

[0008] The suppression circuit is used to suppress electromagnetic signal interference; the suppression circuit includes at least one of a first inlet suppression circuit, a second inlet suppression circuit, a first source suppression circuit, a second source suppression circuit, a first outlet suppression circuit, and a second outlet suppression circuit;

[0009] The first entry suppression circuit is located between the first filter circuit and the rectifier circuit, the second entry suppression circuit is located between the rectifier circuit and the power switch chip, the first source suppression circuit is connected in parallel with both ends of the power switch chip, the second source suppression circuit is connected in parallel with the freewheeling circuit, the first exit suppression circuit is located between the power switch chip and the first inductor, the first ground wire is connected to the second exit suppression circuit and the rectifier bridge circuit, and the second exit suppression circuit is located between the freewheeling circuit and the first ground wire.

[0010] In a possible implementation manner, the AC power port includes a live port and a neutral port, the rectifier circuit includes a first diode and a second diode, and the first inlet suppression circuit includes a first suppression element and a second suppression element;

[0011] The live port is connected to the first suppression element, and the first suppression element is connected to the first diode;

[0012] The neutral line port is connected to the second suppression element, and the second suppression element is connected to the second diode.

[0013] In a possible implementation manner, the second inlet suppression circuit includes a third suppression element;

[0014] The rectifier circuit is connected to the third suppression element, and the third suppression element is connected to the power switch chip.

[0015] In a possible implementation manner, the first source suppression circuit includes a first resistor and a first capacitor, and the power switch chip includes at least one switch input port and a switch output port;

[0016] One end of the first resistor is connected to the at least one switch input port, the other end of the first resistor is connected to the first capacitor, and the other end of the first capacitor is connected to the switch output port.

[0017] In a possible implementation manner, the freewheeling circuit includes a third diode, and the power switch chip includes a switch output port;

[0018] The second source suppression circuit includes a fourth suppression element and / or a second filtering circuit;

[0019] The fourth suppression element is connected to the switch output port and the cathode of the third diode respectively;

[0020] The second filtering circuit is connected to the switch output port and the anode of the third diode respectively, wherein the second filtering circuit includes a second resistor and a second capacitor.

[0021] In a possible implementation manner, the first outlet suppression circuit includes a fifth suppression element, and the power switch chip includes a switch output port;

[0022] The fifth suppression element is connected to the switch output port and the first inductor respectively.

[0023] In a possible implementation manner, the freewheeling circuit includes a third diode, and the second output suppression circuit includes a sixth suppression element, and the sixth suppression element is respectively connected to the anode of the third diode and the first inductor.

[0024] In a possible implementation, the electromagnetic interference filtering circuit also includes a third capacitor and a third resistor, the third capacitor is connected to the sixth suppression element or the positive electrode of the third diode, the third capacitor is also connected to the first inductor, the third resistor is connected to the first inductor, and the third resistor is also connected to the sixth suppression element or the positive electrode of the third diode.

[0025] In a possible implementation, the electromagnetic interference filtering circuit also includes a fourth capacitor and a fourth resistor, the fourth resistor is respectively connected to the rectifier circuit and the fourth capacitor, the fourth resistor is also connected to the second inlet suppression circuit or the power switch chip, and the fourth capacitor is connected to the freewheeling circuit.

[0026] In a second aspect, an embodiment of the present application provides an electronic device, comprising the electromagnetic interference filtering circuit as described in any one of the first aspects.

[0027] The embodiment of the present application provides an electromagnetic interference filtering circuit and an electronic device. In the method, the electromagnetic interference filtering circuit includes an AC power port, a first filtering circuit, a rectifier circuit, a rectifier bridge circuit, a power switch chip, a first inductor, a freewheeling circuit, a suppression circuit, a DC output port and a first ground wire; the AC power port, the first filtering circuit, the rectifier circuit, the power switch chip, the first inductor, and the DC output port are connected in sequence, the first filtering circuit is also connected to the rectifier bridge circuit, the power switch chip is also connected to one end of the freewheeling circuit, the other end of the freewheeling circuit is connected to the DC output port, and the other end of the freewheeling circuit is also connected to the rectifier bridge circuit and the rectifier circuit; the suppression circuit is used to suppress Electromagnetic signal interference; the suppression circuit includes at least one of a first entry suppression circuit, a second entry suppression circuit, a first source suppression circuit, a second source suppression circuit, a first exit suppression circuit and a second exit suppression circuit; the first entry suppression circuit is located between the first filter circuit and the rectifier circuit, the second entry suppression circuit is located between the rectifier circuit and the power switch chip, the first source suppression circuit is connected in parallel with both ends of the power switch chip, the second source suppression circuit is connected in parallel with the freewheeling circuit, the first exit suppression circuit is located between the power switch chip and the first inductor, the first ground wire is connected to the second exit suppression circuit and the rectifier bridge circuit, and the second exit suppression circuit is located between the freewheeling circuit and the first ground wire. In this way, adding at least one suppression circuit can effectively suppress the high-frequency interference signal of the entire loop, reduce processing requirements, and improve the stability of electromagnetic compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the present application, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 A schematic diagram of the position of installing a magnetic ring provided in an embodiment of the present application;

[0030] Figure 2 A schematic diagram of the structure of an electromagnetic interference filter circuit provided in an embodiment of the present application;

[0031] Figure 3 A schematic diagram of the structure of another electromagnetic interference filtering circuit provided in an embodiment of the present application;

[0032] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0033] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments.

[0034] Reference numerals:

[0035] 101-power line; 102-magnetic ring; 103-induction cooker; 201-AC power port; 202-first filter circuit; 203-rectifier circuit; 204-rectifier bridge circuit; 205-power switch chip; 206-first inductor; 207-freewheeling circuit; 208-DC output port; 209-first ground wire; 210-first entry suppression circuit; 211-second entry suppression circuit; 212-first source suppression circuit; 213-second source suppression circuit; 214-first exit suppression circuit; 215-second exit suppression circuit; 301-live port; 302-neutral port; 303-first diode; 304-second diode; 305-first suppression element; 306-second suppression element; 307-third suppression element; 308-first resistor; 309-first capacitor; 310-third diode; 311-fourth suppression element; 312-second resistor; 313 - second capacitor; 314 - fifth suppression element; 315 - sixth suppression element; 316 - third capacitor; 317 - third resistor; 318 - fourth capacitor; 319 - fourth resistor; 320 - fifth capacitor; 321 - second inductor; 322 - fuse; 323 - rectifier bridge element; 324 - sixth capacitor. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0038] In the present application, the term "include" and its variations may refer to non-restrictive inclusion; the term "or" and its variations may refer to "and / or". The terms "first", "second", etc. in the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In the present application, "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previously associated objects are in an "or" relationship.

[0039] Induction cookers are electrical cooking appliances that use electromagnetic induction for heating. During normal operation, induction cookers can generate electromagnetic interference through high-frequency current radiation, power circuit conduction, and harmonic generation, which may have varying degrees of impact on surrounding electronic equipment and the power grid environment.

[0040] In the related art, in order to suppress electromagnetic interference, it is necessary to add a common mode suppression circuit inside the induction cooker product. For example, a magnetic ring can be added to the power cord to suppress the radiation of the internal interference source to the external space. The position of the magnetic ring needs to be ensured to be far away from the interference source to prevent the interference line from affecting the power cord in front of the magnetic ring. The position of the magnetic ring can occupy the space inside the product, or be fixed on the power cord outside the product.

[0041] Next, combine Figure 1 , an example is given to illustrate the position of the magnetic ring.

[0042] Figure 1 A schematic diagram of the position of the magnetic ring provided in the embodiment of the present application. Figure 1 , Figure 1 The induction cooker may include at least a power cord 101 , a magnetic ring 102 and an induction cooker 103 .

[0043] The power cord 101 is connected to the induction cooker 103 .

[0044] A magnetic ring 102 is added to the power cord 101. The conductor of the power cord 101 needs to be wound around the magnetic ring 102 for at least one turn, or even more turns. The position of the magnetic ring 102 also needs to be fixed. It can be fixed by a cable tie or a heat shrink tubing, or by integral injection molding.

[0045] In the above processing, the processing requirements of the magnetic ring are high, resulting in low stability of electromagnetic compatibility.

[0046] In order to solve the above technical problems, an embodiment of the present application provides an electromagnetic interference filtering circuit. By adding at least one suppression circuit in the circuit that converts alternating current into direct current, the high-frequency interference signal of the entire circuit can be effectively suppressed, the processing requirements are reduced, and the stability of electromagnetic compatibility is improved.

[0047] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0048] Figure 2 This is a schematic diagram of the structure of an electromagnetic interference filter circuit provided in an embodiment of the present application. Figure 2 , Figure 2 It includes an electromagnetic interference filtering circuit, which includes an AC power port 201, a first filtering circuit 202, a rectifier circuit 203, a rectifier bridge circuit 204, a power switch chip 205, a first inductor 206, a freewheeling circuit 207, a suppression circuit, a DC output port 208 and a first ground wire 209.

[0049] The AC power port 201, the first filter circuit 202, the rectifier circuit 203, the power switch chip 205, the first inductor 206, and the DC output port 208 are connected in sequence, the first filter circuit 202 is also connected to the rectifier bridge circuit 204, the power switch chip 205 is also connected to one end of the freewheeling circuit 207, the other end of the freewheeling circuit 207 is connected to the DC output port 208, and the other end of the freewheeling circuit 207 is also connected to the rectifier bridge circuit 204 and the rectifier circuit 203;

[0050] The suppression circuit is used to suppress electromagnetic signal interference; the suppression circuit includes at least one of a first inlet suppression circuit 210, a second inlet suppression circuit 211, a first source suppression circuit 212, a second source suppression circuit 213, a first outlet suppression circuit 214 and a second outlet suppression circuit 215;

[0051] The first entry suppression circuit 210 is located between the first filter circuit 202 and the rectifier circuit 203, the second entry suppression circuit 211 is located between the rectifier circuit 203 and the power switch chip 205, the first source suppression circuit 212 is connected in parallel with both ends of the power switch chip 205, the second source suppression circuit 213 is connected in parallel with the freewheeling circuit 207, the first exit suppression circuit 214 is located between the power switch chip 205 and the first inductor 206, the first ground wire 209 is connected to the second exit suppression circuit 215 and the rectifier bridge circuit 204, and the second exit suppression circuit 215 is located between the freewheeling circuit 207 and the first ground wire 209.

[0052] The AC power port 201 is used to connect to an external AC power source to provide power input for the entire circuit system.

[0053] For example, external AC mains (usually 220V, 50Hz AC for household use) enters the circuit through the AC power port 201. Afterwards, the input AC power is processed by subsequent circuit modules in turn to provide a stable DC power supply for the induction cooker connected to the DC output port 208.

[0054] The first filter circuit 202 can be used to perform preliminary filtering to filter out some high-frequency interference signals that may be carried on the AC power line.

[0055] The rectifier circuit 203 may be used to convert the alternating current input from the first filter circuit 202 into direct current.

[0056] The rectifier bridge circuit 204 can be used to implement full-wave rectification to make the output DC voltage and current more stable.

[0057] The power switch chip 205 can be used to perform voltage conversion, reducing the voltage to a low voltage value that meets the weak current requirements, so as to provide a suitable voltage output for subsequent circuits or devices that require low voltage power supply, and meet the working voltage requirements of the weak current part.

[0058] The first inductor 206 can be used when the power switch chip 205 performs a switching action. The current will pass through the first inductor 206. When the current increases, the inductor will store a part of the electric energy, which exists around the inductor coil in the form of magnetic field energy. When the switching action of the power switch core 205 causes the current to decrease, the magnetic field energy stored in the inductor will be converted into electric energy and released to continue to maintain the current flow in the circuit, playing a certain buffering role, so that the current in the circuit will not fluctuate too much due to the frequent switching of the power switch chip 205, thereby ensuring the relative stability of the circuit current.

[0059] The freewheeling circuit 207 can be used for the power switch chip 205 to perform switching actions, and when in the off state, the current path in the circuit will be cut off. The freewheeling circuit 207 can provide an additional current path at this time, so that the current that originally flowed when the power switch chip was turned on can continue to flow, maintaining the continuity of the current.

[0060] The suppression circuit can be used to block interference paths at different locations to suppress electromagnetic signal interference.

[0061] The suppression circuit can effectively reduce the impact of electromagnetic interference signals on various important components in the circuit (such as the rectifier circuit 203, the power switch chip 205, the freewheeling circuit 207, the first inductor 206, etc.) by setting different sub-circuits of the suppression circuit 208 at various key positions, so that these components can operate in a relatively clean electromagnetic environment, thereby ensuring their normal working state.

[0062] The DC output port 208 can be used to provide the load with appropriate DC power after being processed inside the circuit according to the specific needs of the connected load.

[0063] The rectifier bridge circuit 204 may be connected to a first ground line 209 .

[0064] The second outlet suppression circuit 215 may be connected to the first ground line 209 .

[0065] The rectifier circuit 203 may be connected to the second ground line.

[0066] It should be noted that other elements may exist between the DC output port 208 and the first ground line 209 , which are not shown in the figure and are not limited here.

[0067] In this embodiment, the electromagnetic interference filtering circuit includes an AC power port, a first filtering circuit, a rectifier circuit, a rectifier bridge circuit, a power switch chip, a first inductor, a freewheeling circuit, a suppression circuit, a DC output port and a first ground wire; the AC power port, the first filtering circuit, the rectifier circuit, the power switch chip, the first inductor, and the DC output port are connected in sequence, the first filtering circuit is also connected to the rectifier bridge circuit, the power switch chip is also connected to one end of the freewheeling circuit, the other end of the freewheeling circuit is connected to the DC output port, and the other end of the freewheeling circuit is also connected to the rectifier bridge circuit and the rectifier circuit; the suppression circuit is used to suppress electromagnetic signal interference; the suppression circuit It includes at least one of a first inlet suppression circuit, a second inlet suppression circuit, a first source suppression circuit, a second source suppression circuit, a first outlet suppression circuit and a second outlet suppression circuit; the first inlet suppression circuit is located between the first filter circuit and the rectifier circuit, the second inlet suppression circuit is located between the rectifier circuit and the power switch chip, the first source suppression circuit is connected in parallel with both ends of the power switch chip, the second source suppression circuit is connected in parallel with the freewheeling circuit, the first outlet suppression circuit is located between the power switch chip and the first inductor, the first ground wire is connected to the second outlet suppression circuit and the rectifier bridge circuit, and the second outlet suppression circuit is located between the freewheeling circuit and the first ground wire. In this way, adding at least one suppression circuit can effectively suppress the high-frequency interference signal of the entire loop, reduce processing requirements, and improve the stability of electromagnetic compatibility.

[0068] Next, combine Figure 3 , the first entry suppression circuit 210, the second entry suppression circuit 211, the first source suppression circuit 212, the second source suppression circuit 213, the first exit suppression circuit 214 and the second exit suppression circuit 215 in the suppression circuit are further explained.

[0069] Figure 3 This is a schematic diagram of the structure of another electromagnetic interference filter circuit provided in the embodiment of the present application. Figure 3 , Figure 3 Includes EMI filtering circuitry.

[0070] The electromagnetic interference filtering circuit includes an AC power port 201, a first filtering circuit 202, a rectifier circuit 203, a rectifier bridge circuit 204, a power switch chip 205, a first inductor 206, a freewheeling circuit 207 and a suppression circuit.

[0071] The suppression circuit includes at least one of a first inlet suppression circuit 210 , a second inlet suppression circuit 211 , a first source suppression circuit 212 , a second source suppression circuit 213 , a first outlet suppression circuit 214 , and a second outlet suppression circuit 215 .

[0072] The first filtering circuit 202 may include a fifth capacitor 320 and a second inductor 321 .

[0073] A fuse 322 may be included between the AC power port 201 and the first filter circuit 202 .

[0074] The rectifier bridge circuit may include a rectifier bridge element 323 and a sixth capacitor 324 .

[0075] In a possible implementation, the AC power port 201 includes a live port 301 and a neutral port 302 , the rectifier circuit includes a first diode 303 and a second diode 304 , and the first inlet suppression circuit 210 includes a first suppression element 305 and a second suppression element 306 ;

[0076] The live port 301 is connected to the first suppression element 305 , and the first suppression element 305 is connected to the first diode 303 ;

[0077] The neutral line terminal 302 is connected to a second suppression element 306 , and the second suppression element 306 is connected to a second diode 304 .

[0078] The first diode 303 and the second diode 304 can utilize the unidirectional conductivity of the diode to rectify the input AC power, so as to convert the input AC power into DC power within a complete AC cycle.

[0079] The first inlet suppression circuit 210 may be located between the first filter circuit 202 and the rectifier circuit 203. The first inlet suppression circuit 210 may be used to intercept the electromagnetic interference signal on the path of propagation from the first filter circuit 202 to the rectifier circuit 203. The first suppression element 305 may be used to intercept the electromagnetic interference signal propagating toward the first diode 303, and the second suppression element 306 may be used to intercept the electromagnetic interference signal propagating toward the second diode 304.

[0080] The first suppression element 305 and the second suppression element 306 may be magnetic beads or inductance elements respectively.

[0081] In one possible implementation, the second inlet suppression circuit 211 includes a third suppression element 307;

[0082] The rectifier circuit 203 is connected to the third suppression element 307 , and the third suppression element 307 is connected to the power switch chip 205 .

[0083] The third suppression element 307 can be used to intercept the electromagnetic interference signal on the path where it propagates from the rectifier circuit 203 to the power switch chip 205 , so as to further suppress the interference signal.

[0084] The third suppression element 307 may be a magnetic bead or an inductor element.

[0085] In a possible implementation, the first source suppression circuit 212 includes a first resistor 308 and a first capacitor 309, and the power switch chip 205 includes at least one switch input port and a switch output port;

[0086] One end of the first resistor 308 is connected to at least one switch input port, the other end of the first resistor 308 is connected to the first capacitor 309, and the other end of the first capacitor 309 is connected to the switch output port.

[0087] In the operation process of the power switch chip 205, the switch input port can be used to control the on and off operations of the switch elements inside the chip. When these switch actions occur, electromagnetic interference is likely to be generated.

[0088] One end of the first resistor 308 is connected to at least one switch input port. When a signal change at the switch input port causes electromagnetic interference, the first resistor 308 can play a certain role in blocking the electromagnetic interference. It limits the rapid change of current through its own resistance characteristics, thereby slowing down the generation and propagation speed of electromagnetic interference signals and preliminarily suppressing the interference generated by the switch input port.

[0089] The other end of the first resistor 308 is connected to the first capacitor 309, and the other end of the first capacitor 309 is connected to the switch output port. After the first resistor 308 performs preliminary suppression on the interference signal, the first capacitor 309 further plays a role. The capacitor has the characteristic of storing electrical energy. For high-frequency interference signals, it presents a low impedance characteristic, and can absorb and store the remaining interference signal after being blocked by the first resistor 308, further reducing the strength of the interference signal.

[0090] Optionally, the first source suppression circuit 212 includes a first capacitor 309 , one end of the first capacitor 309 is connected to at least one switch input port, and the other end of the first capacitor 309 is connected to the switch output port.

[0091] In the power switch chip 205, when the switch element of the chip needs to be accurately turned on or off according to the switch input port signal, if the switch input port signal changes too drastically, the switch element may malfunction such as premature turn-on, delayed turn-off, etc. The first source suppression circuit 212 adjusts the switch input port signal to ensure that the switch element can be accurately turned on and off in the expected manner, thereby stabilizing the working state of the power switch chip 205.

[0092] In a possible implementation, the freewheeling circuit 207 includes a third diode 310, and the power switch chip includes a switch output port;

[0093] The second source suppression circuit 213 includes a fourth suppression element 311 and / or a second filter circuit, and the second filter circuit includes a second resistor 312 and a second capacitor 313;

[0094] The fourth suppression element 311 is connected to the switch output port and the cathode of the third diode 310 respectively;

[0095] The second filter circuit is connected to the switch output port and the anode of the third diode 310 .

[0096] The switch output port is connected to the second resistor 312 , the second resistor 312 is connected to the second capacitor 313 , and the second capacitor 313 is connected to the anode of the third diode 310 .

[0097] The third diode 310 can be used to maintain current continuity when the power switch chip 205 is turned off.

[0098] The third diode 310 may also generate electromagnetic interference when working.

[0099] The fourth suppression element 311 is connected to the switch output port and the cathode of the third diode 310 respectively. When the third diode 310 generates an electromagnetic interference signal.

[0100] The fourth suppression element 311 can suppress the interference signal, and can reduce the intensity of the electromagnetic interference propagating from the cathode direction of the third diode 310, thereby preventing it from causing excessive impact on external devices and subsequent circuits.

[0101] The fourth suppression element 311 may be a magnetic bead or an inductor element.

[0102] The second resistor 312 and the second capacitor 313 in the second filter circuit can not only suppress electromagnetic interference, but also play a certain role in regulating the current in the freewheeling circuit 207.

[0103] Optionally, the second filtering circuit may include a second capacitor 313 .

[0104] The second source suppression circuit 213 can effectively suppress the electromagnetic interference generated by the freewheeling circuit 207 .

[0105] In a possible implementation, the first outlet suppression circuit 214 includes a fifth suppression element 314, and the power switch chip includes a switch output port;

[0106] The fifth suppression element 314 is connected to the switch output port and the first inductor 206 , respectively.

[0107] The fifth suppression element 314 is located between the power switch chip 205 and the first inductor 206, and can be used to intercept the electromagnetic interference signal on the path of propagation from the power switch chip 205 to the first inductor 206. The power switch chip 205 generates electromagnetic interference during operation, such as when the internal switch element is frequently turned on and off, high-frequency conduction interference is generated. When these interference signals try to enter the first inductor 206, the fifth suppression element 314 can suppress the interference signals and prevent them from passing through, thereby reducing the amount of interference signals entering the first inductor 206.

[0108] The fifth suppression element 314 may be a magnetic bead or an inductor element.

[0109] In a possible implementation, the freewheeling circuit 207 includes a third diode 310 , and the second output suppression circuit includes a sixth suppression element 315 , which is connected to the anode of the third diode 310 and the first inductor 206 , respectively.

[0110] The third diode 310 may generate electromagnetic interference when performing freewheeling operations, etc. When these interference signals try to enter the first inductor 206 , the sixth suppression element 315 can suppress these interference signals and prevent them from passing through, thereby reducing the amount of interference signals entering the first inductor 206 .

[0111] The sixth suppression element 315 may be a magnetic bead or an inductor element.

[0112] In a possible implementation, the electromagnetic interference filtering circuit further includes a third capacitor 316 and a third resistor 317, the third capacitor 316 is connected to the sixth suppression element 315 or the positive electrode of the third diode 310, the third capacitor 316 is also connected to the first inductor 206, the third resistor 317 is connected to the first inductor 206, and the third resistor 317 is also connected to the sixth suppression element 315 or the positive electrode of the third diode 310.

[0113] The third capacitor 316 and the third resistor 317 work together to filter out high-frequency interference signals on the propagation path from the third diode 310 to the first inductor 206. During the propagation of the electromagnetic interference signal from the freewheeling circuit 207 to the first inductor 206, since the capacitor exhibits a low impedance characteristic to the high-frequency signal, the third capacitor 316 can partially absorb and bypass the high-frequency interference signal, making it difficult for it to pass through the subsequent circuit.

[0114] In a possible implementation, the electromagnetic interference filtering circuit also includes a fourth capacitor 318 and a fourth resistor 319, the fourth resistor 319 is connected to the rectifier circuit 203 and the fourth capacitor 318 respectively, the fourth resistor 319 is also connected to the second inlet suppression circuit 211 or the power switch chip 205, and the fourth capacitor 318 is connected to the freewheeling circuit 207.

[0115] The fourth capacitor 318 and the fourth resistor 319 may together form a filter circuit for filtering the electromagnetic interference signal on the propagation path from the rectifier circuit 203 to the freewheeling circuit 207 .

[0116] Below, an example is given to illustrate a case where the suppression circuit includes the first entry suppression circuit 210 and the second source suppression circuit 213 .

[0117] The electromagnetic interference filtering circuit includes an AC power port 201, a first filtering circuit 202, a rectifier circuit 203, a rectifier bridge circuit 204, a power switch chip 205, a first inductor 206, a freewheeling circuit 207 and a suppression circuit.

[0118] The suppression circuit includes a first entry suppression circuit 210 and a second source suppression circuit 213 .

[0119] The first inlet suppression circuit 210 may be used to intercept the electromagnetic interference signal on the path where it propagates from the first filtering circuit 202 to the rectifying circuit 203 .

[0120] The first inlet suppression circuit 210 can be used to intercept the electromagnetic interference signal on the path where it propagates from the first filtering circuit 202 to the rectifying circuit 203 .

[0121] In this embodiment, the suppression circuit includes at least one of a first entry suppression circuit, a second entry suppression circuit, a first source suppression circuit, a second source suppression circuit, a first exit suppression circuit, and a second exit suppression circuit; the first entry suppression circuit is located between the first filter circuit and the rectifier circuit, the second entry suppression circuit is located between the rectifier circuit and the power switch chip, the first source suppression circuit is connected in parallel with both ends of the power switch chip, the second source suppression circuit is connected in parallel with the freewheeling circuit, the first exit suppression circuit is located between the power switch chip and the first inductor, and the second exit suppression circuit is located between the freewheeling circuit and the first inductor. In this way, by adding at least one suppression circuit, the high-frequency interference signal of the entire loop can be effectively suppressed, and the processing requirements are reduced, and the stability of electromagnetic compatibility is improved.

[0122] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 4 , Figure 4 It may include the electromagnetic interference filtering circuit described in any one of the above embodiments.

[0123] The above are only preferred specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes within the technical scope disclosed in the present application according to the technical solution and application concept of the present application, which should be covered by the protection scope of the present application.

[0124] Those skilled in the art may make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. An electromagnetic interference filtering circuit, characterized in that: The electromagnetic interference filtering circuit includes an AC power port, a first filtering circuit, a rectifier circuit, a rectifier bridge circuit, a power switch chip, a first inductor, a freewheeling circuit, a suppression circuit, a DC output port and a first ground wire; The AC power port, the first filter circuit, the rectifier circuit, the power switch chip, the first inductor, and the DC output port are connected in sequence, the first filter circuit is also connected to the rectifier bridge circuit, the power switch chip is also connected to one end of the freewheeling circuit, the other end of the freewheeling circuit is connected to the DC output port, and the other end of the freewheeling circuit is also connected to the rectifier bridge circuit and the rectifier circuit; The suppression circuit is used to suppress electromagnetic signal interference; the suppression circuit includes at least one of a first inlet suppression circuit, a second inlet suppression circuit, a first source suppression circuit, a second source suppression circuit, a first outlet suppression circuit, and a second outlet suppression circuit; The first entry suppression circuit is located between the first filter circuit and the rectifier circuit, the second entry suppression circuit is located between the rectifier circuit and the power switch chip, the first source suppression circuit is connected in parallel with both ends of the power switch chip, the second source suppression circuit is connected in parallel with the freewheeling circuit, the first exit suppression circuit is located between the power switch chip and the first inductor, the first ground wire is connected to the second exit suppression circuit and the rectifier bridge circuit, and the second exit suppression circuit is located between the freewheeling circuit and the first ground wire.

2. The electromagnetic interference filtering circuit according to claim 1, characterized in that: The AC power port includes a live port and a neutral port, the rectifier circuit includes a first diode and a second diode, and the first inlet suppression circuit includes a first suppression element and a second suppression element; The live port is connected to the first suppression element, and the first suppression element is connected to the first diode; The neutral line port is connected to the second suppression element, and the second suppression element is connected to the second diode.

3. The electromagnetic interference filter circuit according to claim 1 or 2, characterized in that: The second inlet suppression circuit includes a third suppression element; The rectifier circuit is connected to the third suppression element, and the third suppression element is connected to the power switch chip.

4. The electromagnetic interference filter circuit according to any one of claims 1 to 3, characterized in that: The first source suppression circuit includes a first resistor and a first capacitor, and the power switch chip includes at least one switch input port and a switch output port; One end of the first resistor is connected to the at least one switch input port, the other end of the first resistor is connected to the first capacitor, and the other end of the first capacitor is connected to the switch output port.

5. The electromagnetic interference filtering circuit according to any one of claims 1 to 4, characterized in that: The freewheeling circuit includes a third diode, and the power switch chip includes a switch output port; The second source suppression circuit includes a fourth suppression element and / or a second filtering circuit; The fourth suppression element is connected to the switch output port and the cathode of the third diode respectively; The second filtering circuit is connected to the switch output port and the anode of the third diode respectively, wherein the second filtering circuit includes a second resistor and a second capacitor.

6. The electromagnetic interference filtering circuit according to any one of claims 1 to 5, characterized in that: The first outlet suppression circuit includes a fifth suppression element, and the power switch chip includes a switch output port; The fifth suppression element is connected to the switch output port and the first inductor respectively.

7. The electromagnetic interference filtering circuit according to any one of claims 1 to 6, characterized in that: The freewheeling circuit includes a third diode, and the second output suppression circuit includes a sixth suppression element, and the sixth suppression element is respectively connected to the anode of the third diode and the first inductor.

8. The electromagnetic interference filtering circuit according to any one of claims 1 to 7, characterized in that: The electromagnetic interference filtering circuit also includes a third capacitor and a third resistor, the third capacitor is connected to the sixth suppression element or the positive electrode of the third diode, the third capacitor is also connected to the first inductor, the third resistor is connected to the first inductor, and the third resistor is also connected to the sixth suppression element or the positive electrode of the third diode.

9. The electromagnetic interference filtering circuit according to any one of claims 1 to 8, characterized in that: The electromagnetic interference filtering circuit also includes a fourth capacitor and a fourth resistor, the fourth resistor is connected to the rectifier circuit and the fourth capacitor respectively, the fourth resistor is also connected to the second inlet suppression circuit or the power switch chip, and the fourth capacitor is connected to the freewheeling circuit.

10. An electronic device, characterized in that: The electronic device comprises the electromagnetic interference filtering circuit as claimed in any one of claims 1 to 9.

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