A multi-functional wideband common mode filter

Abstract

The application provides a multifunctional wideband common mode filter, comprising an integrated common mode filter and an electrostatic protection module, the common mode filter comprising a coupled inductor with common mode rejection capability, the coupled inductor being composed of multiple inductive couplings, the electrostatic protection module being provided with multiple electrostatic protection devices and at least one inductor, the electrostatic protection devices and the inductor in the electrostatic protection module forming a series LC resonant circuit with common mode rejection capability, the coupled inductor and the electrostatic protection module further forming a wideband series LC resonant circuit with wideband common mode rejection capability, the multiple electrostatic protection devices in the electrostatic protection module being three electrostatic protection devices, and each two adjacent electrostatic protection devices in the three electrostatic protection devices being coupled to form a low-impedance electrostatic discharge path. The application has the beneficial effect that the common mode filter can realize wideband common mode rejection capability and electrostatic protection capability.

Description

Technical Field

[0001] This invention relates to the field of electrostatic discharge protection device technology, and specifically to a multifunctional broadband common-mode filter. Background Technology

[0002] Modern high-speed communication interfaces (such as USB 4.0 and HDMI 2.1) generally employ a differential signal transmission architecture in their data transmission design. This architecture, relying on the complementary signal characteristics of differential pairs, can support high-speed data interaction at the Gbps level, making it a core technical solution for meeting the transmission needs of scenarios such as high-definition audio-visual and high-speed peripheral interconnection.

[0003] In practical engineering applications of differential signal transmission, a large amount of common-mode noise is generated in the differential signal lines due to factors such as PCB (Printed Circuit Board) routing errors, differential pair impedance mismatch, and differences in device parasitic parameters. This noise spreads outward in the form of electromagnetic radiation, causing serious interference to surrounding wireless communication links. Specifically, it manifests as decreased antenna receiving sensitivity, increased wireless signal bit error rate, and even causes wireless communication link interruption, severely restricting the electromagnetic compatibility performance of electronic equipment.

[0004] To address the common-mode noise suppression requirements of differential high-speed signal lines, the mainstream industry solution is to deploy common-mode filters in the transmission link. This device possesses the dual characteristics of common-mode signal attenuation and interference-free differential-mode signal transmission. It can accurately filter out common-mode noise components in differential links, suppressing electromagnetic radiation interference at its source and ensuring the coordinated and stable operation of high-speed communication interfaces and surrounding wireless systems. It is a key passive component in the electromagnetic compatibility design of high-speed communication interfaces.

[0005] As shown in Figure 1(a), a typical existing common-mode filter consists of a pair of coupled inductors (L1 and L2). For differential-mode signals, the magnetic field lines of these coupled inductors cancel each other out, presenting a low impedance, allowing the differential signal to pass smoothly. For common-mode signals, the magnetic field lines of these coupled inductors superimpose, presenting a high impedance, effectively suppressing common-mode noise. Furthermore, as shown in Figure 1(b), a broadband common-mode suppressor with integrated electrostatic discharge (ESD) protection is proposed in the prior art. By adding TVS diodes (TVS1 and TVS2) and inductor L3 between the IN+ and IN- ports and the ground port, a series LC resonant branch can be formed, creating a new common-mode suppression frequency, thereby broadening the overall product's common-mode suppression bandwidth. Simultaneously, the TVS diodes also provide ESD protection. In this case, to prevent inductor L3 from deteriorating the ESD protection effect, an additional TVS diode (TVS3) needs to be connected in parallel to clamp the transient high voltage of the inductor. However, the presence of the aforementioned TVS3 will undoubtedly increase the parasitic resistance of the ESD discharge channel, thereby inevitably deteriorating the overall electrostatic discharge and surge clamping voltage and protection effect of the product. Therefore, this method is still difficult to meet people's usage needs. Summary of the Invention

[0006] To address the problems in existing technologies, this invention provides a multifunctional broadband common-mode filter. By incorporating a cooperating common-mode filter and an electrostatic discharge (ESD) protection module within the multifunctional broadband common-mode filter, and further combining the coupling inductor and the ESD protection module to form a broadband series LC resonant circuit with broadband common-mode rejection capability, a low-impedance ESD discharge path is formed between every two ESD protection devices within the ESD protection module. This enables the common-mode filter to achieve both broadband common-mode rejection and ESD protection capabilities. Furthermore, the device structure of the multi-port TVS diode is further optimized. By constructing additional low-impedance ESD discharge paths, the ESD clamping voltage is significantly optimized, improving the system-level ESD and surge protection performance. This solves the typical problems in existing technologies, such as poor common-mode filter performance and the deterioration of ESD and surge clamping voltage caused by adding TVS diodes.

[0007] This invention provides a multifunctional broadband common-mode filter, comprising an integrated common-mode filter and an electrostatic discharge (ESD) protection module. The common-mode filter includes a coupled inductor with common-mode rejection capability, which is composed of multiple coupled inductors. The ESD protection module contains multiple ESD protection devices and at least one inductor. The ESD protection devices and inductors in the ESD protection module constitute a series LC resonant circuit with common-mode rejection capability. The coupled inductor can further form a broadband series LC resonant circuit with broadband common-mode rejection capability with the ESD protection module. The multiple ESD protection devices in the ESD protection module are three ESD protection devices, and each pair of adjacent ESD protection devices is coupled to form a low-impedance ESD discharge path.

[0008] In a further improvement to the present invention, the coupling inductor in the common-mode filter is replaced with a single-stage series LC resonant circuit or a multi-stage series LC resonant circuit. The single-stage series LC resonant circuit or the multi-stage series LC resonant circuit can further form a broadband series LC resonant circuit with broadband common-mode rejection capability with the electrostatic protection module.

[0009] The present invention is further improved in that the common-mode filter is manufactured by one or more of the following processes: microwave transmission line, thin film inductor, three-dimensional integrated inductor, bond wire coupling, and silicon integrated inductor.

[0010] In a further improvement, the inductors in the common-mode filter and the electrostatic protection module are planar spiral structures. The planar spiral structure is constructed using various through-hole structures to create a three-dimensional 3D inductor structure. The multiple inductors in the common-mode filter can be formed into the coupled inductor by stacking multiple layers of metal.

[0011] The present invention is further improved in that the electrostatic protection device is one or more of the following: diode, diode string, avalanche diode, Schottky diode, ESD protection array, Zener diode, bipolar transistor, NPN transistor, PNP transistor, silicon controlled rectifier, and field-effect transistor. The manufacturing process of the electrostatic protection device is either a planar manufacturing process or a vertical manufacturing process.

[0012] The present invention is further improved in that the manufacturing process of the common mode filter and the electrostatic protection module is one or more of the following: BCD three-in-one monolithic integration process, nanoscale complementary metal oxide semiconductor process, RF CMOS radio frequency integrated circuit process, microstructure processing process, high voltage integrated circuit process, three-dimensional fin field-effect transistor process, all-around gate transistor process, silicon germanium process, and silicon growth process on insulating substrate.

[0013] The present invention is further improved in that the connection method of the common mode filter and the electronic components in the electrostatic protection module includes one or more of the following: packaged bonding wire, redistribution layer (RDL), metal via (VIA), through silicon via (TSV), glass via (TGV), PCB metal trace, flip-chip interconnect, copper pillar bump interconnect, micro-bump interconnect, redistribution layer bump interconnect, interlayer metal interconnect, wafer-level metal interconnect, heterogeneous integration interconnect, lead frame interconnect, conductive adhesive interconnect, copper damask interconnect, and hybrid bonding.

[0014] The present invention is further improved to be used for broadband common-mode filtering of various port combinations, including I / O ports and ground ports (GND), power ports and I / O ports, power ports and ground ports, I / O ports and I / O ports, signal ports and signal ports, RF ports and ground ports, analog ports and digital ports, sensor ports and ground ports, drive ports and load ports, chip core ports and I / O ports, bus ports and ground ports, and communication ports and ground ports.

[0015] The present invention is further improved in that the layout of the common-mode filter and the electrostatic protection module includes one or more of the following: strip semiconductor layout, ring semiconductor layout, pie semiconductor layout, interdigitated semiconductor layout, comb semiconductor layout, polygon semiconductor layout, circular semiconductor layout, elliptical semiconductor layout, fan-shaped semiconductor layout, grid semiconductor layout, array semiconductor layout, island semiconductor layout, strip interlaced semiconductor layout, ring nested semiconductor layout, polygonal symmetrical semiconductor layout, and irregular symmetrical semiconductor layout.

[0016] The present invention is further improved by adopting an "asymmetric" structure that can protect against negative static electricity in the electrostatic protection module.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: It provides a multifunctional broadband common-mode filter based on a novel structure. By setting a common-mode filter and an electrostatic discharge (ESD) protection module that cooperate with each other within the multifunctional broadband common-mode filter, the coupling inductor can further form a broadband series LC resonant circuit with broadband common-mode rejection capability with the ESD protection module. A low-impedance ESD discharge path is formed between every two ESD protection devices in the ESD protection module, enabling the common-mode filter to achieve broadband common-mode rejection capability and ESD protection capability. Moreover, the device structure of the multi-port TVS diode is further optimized. By constructing an additional low-impedance ESD discharge path, the ESD clamping voltage is significantly optimized, improving the system-level ESD and surge protection effect. This solves the typical problems of poor common-mode filter performance and the deterioration of ESD and surge clamping voltage caused by adding TVS diodes in the prior art. Attached Figure Description

[0018] To more clearly illustrate the solutions in this invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1(a) shows the circuit diagram of a classic common-mode filter. Figure 1(b) shows the circuit diagram of an existing broadband common-mode filter with integrated electrostatic protection. Figure 2 This is a circuit equivalent diagram of a first embodiment of the multifunctional broadband common-mode filter of the present invention; Figure 3(a) is a circuit equivalent diagram of a second embodiment of the multifunctional broadband common-mode filter of the present invention; Figure 3(b) is a layout schematic diagram of a second embodiment of the multifunctional broadband common-mode filter of the present invention; Figure 3(c) is a cross-sectional view of the structure of Embodiment 2 of the multifunctional broadband common-mode filter of the present invention; Figure 3(d) is a cross-sectional view of the structure of Embodiment 2 of the multifunctional broadband common-mode filter of the present invention; Figure 4 This is a layout schematic diagram of a third embodiment of the multifunctional broadband common-mode filter of the present invention; Figure 5 This is the circuit equivalent diagram of Embodiment 4 of the multifunctional broadband common-mode filter of the present invention; Figure 6 This is a cross-sectional view of the structure of a fifth embodiment of the multifunctional broadband common-mode filter of the present invention; Figure 7(a) is a circuit equivalent diagram of Embodiment 6 of the multifunctional broadband common-mode filter of the present invention; Figure 7(b) is a cross-sectional view of the structure of Embodiment 6 of the multifunctional broadband common-mode filter of the present invention; Figure 8 This is a 3D structural schematic diagram of Embodiment Seven of the Multifunctional Broadband Common-Mode Filter of the present invention; Figure 9(a) is a circuit equivalent diagram of an eighth embodiment of the multifunctional broadband common-mode filter of the present invention; Figure 9(b) is a cross-sectional view of the structure of Embodiment 8 of the multifunctional broadband common-mode filter of the present invention.

[0020] In the diagram, 001, 020, 021, 068, and 086 represent node A; 022 and 069 represent node B; and 070 represents node C. 002, 003, 004, 011, 012, 013, 023, 024, 025, 026, 027, 028, 415, 416, 417, 071, 072, 073, 074, 075, and 718 represent inductors; 418 and 535 represent the top surface ground port GND_TOP of the chip; 419 and 536 represent the bottom surface ground port GND_Bottom of the chip. 005, 006, and 007 represent electrostatic discharge (ESD) protection devices; 084 and 085 represent forward-biased diode-type electrostatic discharge (ESD) protection devices; 014, 015, 016, 029, 030, 031, 032, 033, 034, and 078 represent bidirectional NPN transistors; 050, 051, 052, 053, 054, 055, 056, 057, and 058 represent bidirectional PNP transistors; 076 and 077 represent "asymmetric" NPN transistors. 017, 035, 059, and 079 represent the parasitic capacitance between the IN+ port and node A; 018, 036, 060, and 080 represent the parasitic capacitance between the IN port and node A; 019, 037, 061, and 081 represent the parasitic capacitance between the ground port and node A; 062 represents the parasitic capacitance between the IN+ port and node B; 063 represents the parasitic capacitance between the IN port and node B; 064 represents the parasitic capacitance between the ground port and node B; 038 represents the parasitic capacitance between the OUT+ port and node B; 039 represents the parasitic capacitance between the OUT port and node B; 040 represents the parasitic capacitance between the ground port and node B; 065 represents the parasitic capacitance between the OUT+ port and node C; 066 represents the parasitic capacitance between the OUT port and node C; 067 represents the parasitic capacitance between the ground port and node C; 082 and 083 represent the parasitic capacitance of the forward-biased diode; 100, 200, 500, and 700 represent P-type substrates; 400 represents N-type substrates. 101, 102, 103, 201, 202, 203, 402, 403, 504, 507, 510, 703, 705, and 707 represent N-type heavily doped active regions; 104, 204, 404, 503, 505, 506, 508, 509, 511, 704, 706, and 708 represent heavily doped P-type active regions; 401 and 702 represent P-type well regions; 701 represents N-type well regions; 501 represents an N-type epitaxial layer; 502 and 724 represent deep trench isolation; 709 and 711 represent N-type buried layers; 710 and 712 represent P-type buried layers. 105 and 205 represent the first layer of metal; 106 and 206 represent the second layer of metal; 107, 207, 600, 601, 602, 603, 604, and 605 represent planar spiral inductors; 606 represents magnetic field lines; 405 and 512 represent metal interconnects (e.g., wire bonding for packaging, redistribution layer RDL, metal via TSV, glass via TGV, PCB metal traces). 008, 108, 208, 300, 406, 526, 529, 532, and 719 represent low-impedance electrostatic discharge paths from the ground port to the IN+ port. 009, 109, 209, 301, 407, 527, 530, 533, and 720 represent low-impedance electrostatic discharge paths from the ground port to the IN port; 010, 110, 210, 302, 408, 528, 531, 534, and 723 represent low-impedance electrostatic discharge paths from the IN+ port to the IN- port; 721 represents a low-impedance electrostatic discharge path from the IN+ port to the ground port; 722 represents a low-impedance electrostatic discharge path from the IN port to the ground port; 303 represents a low-impedance electrostatic discharge path from the ground port to the OUT+ port; 304 represents a low-impedance electrostatic discharge path from the ground port to the OUT port; 305 represents a low-impedance electrostatic discharge path from the OUT+ port to the OUT- port; 111, 112, 113, 114, 409, 410, 411, 412, 413, 414, 513, 514, 515, 516, 517, 518, 519, 520, 521, 522, 523, 524, 525, 713, 714, 715, 716, and 717 represent metal interconnect lines. Detailed Implementation

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; the terminology used herein and in the specification of the application is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings are used to distinguish different objects and not to describe a particular order.

[0022] 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 the invention. 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.

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0024] like Figure 2 As shown in Figure 9(b), the present invention provides a multifunctional broadband common-mode filter, comprising an integrated common-mode filter and an electrostatic discharge (ESD) protection module. The common-mode filter includes a coupled inductor with common-mode rejection capability, which is composed of multiple coupled inductors. The ESD protection module contains multiple ESD protection devices and at least one inductor. The ESD protection devices and inductors in the ESD protection module constitute a series LC resonant circuit with common-mode rejection capability. The coupled inductor and the ESD protection module further constitute a broadband series LC resonant circuit with broadband common-mode rejection capability. The multiple ESD protection devices in the ESD protection module are three ESD protection devices, and each pair of adjacent ESD protection devices is coupled to form a low-impedance ESD discharge path. The coupled inductor in the common-mode filter can be replaced by a single-stage series LC resonant circuit or a multi-stage series LC resonant circuit. The single-stage series LC resonant circuit or the multi-stage series LC resonant circuit can further constitute a broadband series LC resonant circuit with broadband common-mode rejection capability with the ESD protection module. The structure of the common-mode filter is manufactured using one or more of the following processes: microwave transmission line, thin-film inductor, three-dimensional integrated inductor, bonded wire coupling, and silicon integrated inductor. The inductors in the common-mode filter and electrostatic protection module are planar spiral structures. The planar spiral structure uses various through-hole structures to construct a three-dimensional 3D inductor structure. Multiple inductors in the common-mode filter can form coupled inductors through multi-layer metal stacking.

[0025] like Figure 2 As shown in Figure 9(b), the electrostatic discharge (ESD) protection device is one or more of the following: diode, diode string, avalanche diode, Schottky diode, ESD protection array, Zener diode, bipolar transistor, NPN transistor, PNP transistor, silicon controlled rectifier, and field-effect transistor. The manufacturing process of the ESD protection device is either planar manufacturing or vertical manufacturing. The manufacturing process of the common-mode filter and ESD protection module is one or more of the following: BCD three-in-one monolithic integration process, nanoscale complementary metal-oxide-semiconductor process, RF CMOS radio frequency integrated circuit process, microstructure processing process, high-voltage integrated circuit process, three-dimensional fin field-effect transistor process, all-around gate transistor process, silicon-germanium process, and silicon growth process on insulating substrate. The interconnection methods for electronic components within common-mode filters and electrostatic discharge (ESD) protection modules include one or more of the following: package bonding wires, redistribution layers (RDL), metal vias (VIA), through-silicon vias (TSV), glass vias (TGV), PCB metal traces, flip-chip interconnects, copper pillar bump interconnects, micro-bump interconnects, redistribution layer bump interconnects, interlayer metal interconnects, wafer-level metal interconnects, heterogeneous integrated interconnects, leadframe interconnects, conductive adhesive interconnects, copper damask interconnects, and hybrid bonding. Wideband common-mode filtering can be used for various port combinations, including I / O ports and ground (GND), power ports and I / O ports, power ports and ground ports, I / O ports and I / O ports, signal ports and signal ports, RF ports and ground ports, analog ports and digital ports, sensor ports and ground ports, drive ports and load ports, chip core ports and I / O ports, bus ports and ground ports, and communication ports and ground ports. The layout of common-mode filters and electrostatic discharge (ESD) protection modules includes one or more of the following: strip semiconductor layout, ring semiconductor layout, pie semiconductor layout, interdigitated semiconductor layout, comb semiconductor layout, polygonal semiconductor layout, circular semiconductor layout, elliptical semiconductor layout, fan-shaped semiconductor layout, grid semiconductor layout, array semiconductor layout, island semiconductor layout, interlaced strip semiconductor layout, nested ring semiconductor layout, polygonal symmetrical semiconductor layout, and irregular symmetrical semiconductor layout. The ESD protection module employs an "asymmetric" structure capable of protecting against negative static electricity.

[0026] like Figure 2 The image shows a first embodiment of the multifunctional broadband common-mode filter of the present invention. The structure of this embodiment is as follows: (1) Inductors 002 and 003 form a coupled inductor, providing some common-mode rejection capability.

[0027] (2) The electrostatic protection device 005, electrostatic protection device 006, and inductor 004 form a series LC resonant circuit. Working principle: For differential mode signals, the potential at point A 001 is zero, presenting a high impedance to ground. Therefore, differential mode signals can be smoothly transmitted from the IN+ and IN- ports to the OUT+ and OUT- ports. For common mode signals, the potential at point A 001 is non-zero, which will be discharged to ground through inductor 004, thus contributing additional common mode rejection capability.

[0028] (3) The above-mentioned series LC resonant circuit can achieve broadband common-mode rejection capability by further cooperating with the above-mentioned coupling inductor; and the series LC resonant circuit and the coupling inductor can be set with multi-stage structures to achieve a wider common-mode rejection frequency band; in addition, the above-mentioned coupling inductor can be omitted in some cases, and common-mode filtering can be performed by relying on a single-stage or multi-stage series LC resonant circuit.

[0029] (4) To effectively clamp the transient high voltage on inductor 004 and prevent it from deteriorating the effectiveness of electrostatic discharge and surge protection, an electrostatic discharge protection device 007 in parallel with the inductor is required. There are no restrictions on the type of electrostatic discharge protection device, and it can be any common electrostatic surge protection device, such as diodes, diode strings, Zener diodes, bipolar transistors, NPN transistors, PNP transistors, silicon controlled rectifiers (SCRs), and various high and low voltage field-effect transistors.

[0030] (5) Static electricity protection device 005, static electricity protection device 006, and static electricity protection device 007 are all coupled with a "low impedance discharge channel", such as Figure 2 The “low-impedance electrostatic discharge path 008, low-impedance electrostatic discharge path 009, and low-impedance electrostatic discharge path 010” provide efficient discharge paths for static electricity and surges.

[0031] The working principle of this embodiment for improving the effectiveness of electrostatic discharge and surge protection is as follows: (1) In actual “common model” electrostatic discharge or surge events (such as IN+ port → ground port, or IN- port → ground port), initially, the discharge current will flow through the series topology network composed of electrostatic protection device 005 or electrostatic protection device 006 and electrostatic protection device 007. Afterwards, as the current gradually increases, it will be discharged to ground through “low impedance electrostatic discharge path 008, low impedance electrostatic discharge path 009, low impedance electrostatic discharge path 010” to optimize the clamping voltage and overall protection effectiveness. (2) In actual “different model” electrostatic discharge or surge events (IN+ port « IN- port), initially, the discharge current will flow through the series topology network composed of electrostatic protection device 005 and electrostatic protection device 006. Afterwards, as the current gradually increases, it will be discharged through “low impedance electrostatic discharge path 010” to effectively optimize the electrostatic and surge clamping voltage and protection effect.

[0032] As shown in Figures 3(a)-3(d), this is a second embodiment of the multifunctional broadband common-mode filter of the present invention. This embodiment shows a more detailed circuit equivalent diagram, layout diagram and structural cross-sectional view.

[0033] (1) In Figure 3(a) (circuit equivalent diagram): Inductors 011 and 012 form a coupling inductor, providing some common-mode filtering capability, which can be omitted in some cases. Between the IN+ port, IN- port, and ground port, there are three bidirectional NPN transistors 014, 015, and 016, whose bases are all connected to the same internal common node A. The parasitic capacitances of the emitter junction or collector junction of the three NPN transistors overlap, and are finally represented by capacitors 017, 018, and 019 to represent the parasitic capacitances between the IN+ port, IN- port, and ground port and node A, respectively. In addition, an inductor 013 is connected in series between node A and the ground port, which, together with capacitors 017 and 018, forms an LC resonant circuit, providing additional common-mode rejection capability.

[0034] (2) When electrostatic discharge or surge discharge occurs at the IN+ port to ground, under a small current, the charge will first break down the collector junction of NPN transistor 016 to reach node A, and then reach the ground port through the emitter junction of bidirectional NPN transistor 014. Although this discharge path is not affected by inductor 013, the reverse series structure of the two PN junctions will inevitably increase the on-resistance, thereby deteriorating the clamping voltage. Therefore, in this embodiment, as the electrostatic discharge or surge current gradually increases, bidirectional NPN transistor 014 will be activated, directly discharging most of the current to the ground port. Thanks to the inherent current gain characteristics and high current conductance modulation mechanism of NPN bipolar transistors, the on-resistance of this discharge path is significantly reduced, thereby optimizing the electrostatic discharge and surge clamping voltage of the overall structure.

[0035] (3) For other electrostatic discharge and surge discharge events, such as ground port to IN+ port, IN- port to ground port, ground port to IN- port, IN+ port to IN- port, and IN- port to IN+ port, the discharge path mechanism is similar: through NPN transistor path 108, NPN transistor path 109, and NPN transistor path 110 respectively, the clamping voltage can be effectively optimized for all discharge modes.

[0036] (4) In Figure 3(b) (layout diagram): it can be seen that there are three parallel N-type heavily doped active regions 101, 102, and 103 on the silicon substrate, which are connected to the IN+ port, the ground port, and the IN- port, respectively. On one side of the N-type heavily doped active region, a P-type heavily doped active region 104 is placed to lead the silicon substrate to the internal common node A. In addition, the inductor 013 is obtained by winding a planar spiral inductor 107 around the first layer of metal 105. One end of the inductor is connected to node A, and the other end is connected to the ground port via a jumper wire of the second layer of metal 106. It should be noted that the relative positions of all active regions 101, 102, 103, and 104, as well as the planar spiral inductor 107 in Figure 3(b), are not fixed and can be arbitrarily placed. In addition, the common mode inductor structure is omitted in Figure 3(b). In actual manufacturing, it can also be implemented by a planar spiral inductor structure with a single layer of metal or multiple layers of metal.

[0037] (5) In Figures 3(c) and 3(d) (structural cross-section): it can be seen that the three heavily doped N-type active regions 101, 102 and 103 can be paired to form "horizontal bidirectional NPN transistor paths 108, 109 and 110", which are composed of the heavily doped N-type active region 101, the P-type substrate 100, the heavily doped N-type active region 102, the heavily doped N-type active region 101, the P-type substrate 100, the heavily doped N-type active region 103, the heavily doped N-type active region 102, the P-type substrate 100 and the heavily doped N-type active region 103, in order to achieve the optimization of clamping voltage.

[0038] like Figure 4The figure shows a third embodiment of the multifunctional broadband common-mode filter of the present invention, which, compared with the second embodiment, further optimizes the relative positional relationship between multiple active regions and the planar spiral inductor. As shown, the shapes of the heavily doped N-type active regions 201, 202, and 203 change from strip-shaped to arc-shaped, with the three N-type heavily doped active regions 201, 202, and 203 forming a ring; the shape of the P-type active region 204 also changes from strip-shaped to circular, located at the center of the ring formed by the aforementioned heavily doped N-type active regions 201, 202, and 203; the planar spiral inductor 207 is wound around the outside of the N-type active regions, forming a maximum hollow structure to optimize the quality factor. Note that the common-mode inductor structure is also omitted in the fourth embodiment, and its manufacturing method will not be described in detail. The advantage of Example 3 compared to Example 2 is that the layout of the heavily doped active region is completely symmetrical. Therefore, the bidirectional NPN transistor paths 208, 209, and 210 formed between the three N-type heavily doped active regions 201, 202, and 203 are completely identical. This helps to ensure the consistency of the electrostatic discharge and surge protection levels of the present invention in common-mode discharge events and differential-mode discharge events.

[0039] like Figure 5 The image shows a fourth embodiment of the multifunctional broadband common-mode filter of the present invention. Based on embodiment three, it further adds NPN transistors 032, 033, and 034 and inductor 028 to the OUT+ and OUT- ports, offering the following advantages: (1) Upgraded electrostatic and surge protection capabilities: NPN transistors 032, 033, and 034, together with NPN transistors 029, 030, and 031 at the IN+ and IN- ports, as well as inductors 023, 024, 026, and 027, can form a "secondary protection network" in common-mode and differential-mode discharge modes, thereby improving the electrostatic and surge protection effect.

[0040] (2) Regarding the design of device size: NPN transistors 032, 033, and 034 can be the same size as NPN transistors 029, 030, and 031, respectively, to form completely symmetrical electrostatic discharge and surge robustness, that is, the electrostatic discharge and surge protection capabilities of the IN side port and the OUT side port are exactly the same; Alternatively, they can be designed as asymmetrical structures: In this case, considering the actual application scenario of the present invention, such as the IN side port being close to the interface of the electronic device during installation, while the OUT side port is close to the driver chip side of the electronic device, electrostatic discharge and surge events are more likely to occur on the IN side (interface side). Therefore, NPN transistors 032, 033, and 034 can be designed to be smaller than NPN transistors 029, 030, and 031, which can further reduce the product size and lower the cost while ensuring the electrostatic discharge and surge protection effect.

[0041] (3) The introduction of NPN transistors 032, 033, 034 and inductor 028 can provide additional common-mode rejection points, which is beneficial to further expand the common-mode rejection bandwidth and improve design flexibility.

[0042] The coupling relationships of inductors 023, 024, 026, and 027 are as follows: Inductor 023 is coupled to inductor 024, and inductor 026 is coupled to inductor 027. Furthermore, inductor 023 can be further positively coupled (or negatively coupled) to inductor 026, and inductor 024 can be further positively coupled (or negatively coupled) to inductor 027. Additionally, depending on the specific application requirements, some inductors can be omitted, such as inductors 026 and 027, or all of them simultaneously.

[0043] like Figure 6 The diagram shows a fifth embodiment of the multifunctional broadband common-mode filter of the present invention, which further optimizes the structure of the electrostatic discharge (ESD) protection device compared to the second embodiment. In this embodiment, the bidirectional NPN transistor path 408 maintains a "horizontal device structure," consisting of an N-type heavily doped active region 402, a P-type well region 401, and an N-type heavily doped active region 403. The bidirectional NPN transistor paths 406 and 407, however, become "vertical device structures," consisting of an N-type heavily doped active region 402, a P-type well region 401, an N-type substrate 400, an N-type heavily doped active region 403, a P-type well region 401, and an N-type substrate 400. This improves integration density, reduces chip footprint, and enhances ESD and surge protection capabilities. In this embodiment, the P-type well region functions as the internal common node A in the second embodiment. At this point, there are two ground ports, GND_TOP and GND_Bottom, on the top and back surfaces of the chip, respectively. These two ports need to be shorted together during later packaging or application. This can be achieved by using packaging bonding wires, redistribution layers (RDL), metal vias, through-silicon vias (TSV), through-glass vias (TGV), PCB metal traces, etc.

[0044] Figures 7(a) and 7(b) show a sixth embodiment of the multifunctional broadband common-mode filter of the present invention. This embodiment is based on embodiment five, but extends to a multi-stage structure to further broaden the common-mode suppression bandwidth. Furthermore, the type of electrostatic discharge (ESD) protection device has been changed from NPN transistors to PNP transistors 050, 051, 052, 053, 054, 055, 056, 057, and 058.

[0045] In Figure 7(a): the common-mode inductor is omitted, and an n-stage cascaded LC resonant network is used. The common-mode resonant points of each stage can be different to maximize the common-mode rejection bandwidth; they can also be superimposed to achieve a stronger common-mode rejection effect for key frequency bands. In this embodiment, the number of stages n can be any positive integer. When the number of stages n is very large, it is essentially equivalent to a distributed circuit network. Therefore, this embodiment is also applicable to common-mode filter structures constructed from microwave transmission lines (such as coplanar waveguides, microstrip lines, etc.).

[0046] Figure 7(b): As shown in the structural cross-sectional view, a deep trench isolation (DTI) structure 502 is used between the multi-stage LC resonant networks to ensure good electrical isolation. In electrostatic discharge and surge events, multiple parallel horizontal bidirectional PNP paths 528, 531, and 534 are responsible for differential mode discharge protection, and multiple parallel vertical bidirectional PNP paths 526, 529, 532, 527, 530, and 533 are responsible for common mode discharge protection. On the top surface and back surface of the chip, there are also two ground ports, GND_TOP and GND_Bottom, which need to be shorted during later packaging or application. This can be achieved using packaging bonding wires, redistribution layers (RDLs), metal vias, through-silicon vias (TSVs), through-glass vias (TGVs), PCB metal traces, etc.

[0047] like Figure 8 The image shows a seventh embodiment of the multifunctional broadband common-mode filter of the present invention, illustrating the spatial arrangement of multiple inductors to clarify their coupling relationships. The inductors are primarily constructed in a "planar spiral structure," distributed across different metal layers or redistribution layers (RDLs).

[0048] (1) Between multiple inductors, as shown in the attached diagram Figure 8 L1 (604), L2 (600), L3 (601), L4 (602)...Ln (603) can form a vertically stacked structure, in which case the magnetic field lines 606 overlap, forming various coupling relationships. (See attached diagram.) Figure 5 Taking Example 4 as an example, inductors 023 and 024 can form a coupled inductor, and inductors 023 and 026 can also form a coupled inductor. Inductors 023, 024, 025, and 026 can also be stacked vertically simultaneously, with their magnetic field lines overlapping to form a coupled inductor. Furthermore, inductor 023 can also form a coupled inductor with inductor 025, and inductor 025 can also form a coupled inductor with inductor 028, further adjusting the common-mode rejection bandwidth. Additionally, coupled inductors can also be achieved using the same metal layer or RDL, as long as the magnetic field lines of the two inductors are superimposed.

[0049] (2) Between multiple inductors, as shown in the attached diagram Figure 8 The Ln603 and Ln'605 in the model can also remain independent of each other. The way to achieve mutual decoupling is to manufacture multiple inductors in the same or different layers of metal or RDL, and ensure that there is no superposition of magnetic field lines between them, or that the superposition of magnetic field lines is so small as to be negligible.

[0050] (3) In addition to the "planar spiral structure" shown above, the inductor structure in this embodiment can also be constructed using various through-hole structures (such as metal vias, metal bumps, and through-silicon vias (TSVs)) to create a three-dimensional 3D inductor structure. Furthermore, magnetic core materials can be flexibly added according to actual needs to further achieve product miniaturization design.

[0051] As shown in Figures 9(a) and 9(b), this is the eighth embodiment of the multifunctional broadband common-mode filter of the present invention. This embodiment is based on the second embodiment and further optimizes the protection effectiveness under negative electrostatic and surge modes. As shown in Figures 9(a)-9(b), path 721 or path 722 is responsible for discharging the positive static electricity and surge charge from the IN+ port or IN- port to the ground port. Path 721 consists of an N-type heavily doped active region 703, an N-type well region 701, an N-type buried layer 709, a P-type buried layer 710, a P-type substrate 700, an N-type well region 701, and an N-type heavily doped active region 705, forming an "asymmetric" NPN transistor 076. Path 722 consists of an N-type heavily doped active region 707, an N-type well region 701, an N-type buried layer 711, a P-type buried layer 712, a P-type substrate 700, an N-type well region 701, and an N-type heavily doped active region 705, forming an "asymmetric" NPN transistor 077. Among them, 709, 710, 711, and 712 are used to adjust the trigger voltage of the electrostatic protection device. Path 723 consists of an N-type heavily doped active region 703, an N-type well region 701, an N-type buried layer 709, a P-type buried layer 710, a P-type substrate 700, a P-type buried layer 712, an N-type buried layer 711, an N-type well region 701, and an N-type heavily doped active region 707, forming a "symmetrical" bidirectional NPN transistor 078, which is responsible for discharging bidirectional static electricity and surge charge between the IN+ and IN- ports.

[0052] Based on this, considering that the signal level of some differential ports is always greater than zero, there are usually a large number of parasitic diodes in the protected circuit or chip between the GND port and the IN+ port (or IN- port). In order to effectively protect them, a forward-biased diode-type electrostatic discharge (ESD) protection device is also required. As shown in Figures 9(a)-9(b), path 719 is composed of a P-type heavily doped active region 704, an N-type well region 701, and an N-type heavily doped active region 703 forming a forward-biased PN diode 084, or path 720 is composed of a P-type heavily doped active region 706, an N-type well region 701, and an N-type heavily doped active region 707 forming a forward-biased diode-type ESD protection device 085 responsible for discharging negative static electricity and surge charge from the ground port to the IN+ port or IN- port. In addition, in this embodiment, the P-type substrate 700 acts as the "internal node A" in embodiment two, and it needs to be shorted to the ground port through an inductor 718. At this point, in order to reduce parasitic resistance, a P-type well region 702 can be selectively added.

[0053] As can be seen from the above, the present invention provides a multifunctional broadband common-mode filter. By setting a common-mode filter and an electrostatic discharge (ESD) protection module that cooperate with each other within the multifunctional broadband common-mode filter, the coupling inductor can further form a broadband series LC resonant circuit with broadband common-mode rejection capability with the ESD protection module. A low-impedance ESD discharge path is formed between every two ESD protection devices in the ESD protection module, enabling the common-mode filter to achieve broadband common-mode rejection capability and ESD protection capability. Moreover, the device structure of the multi-port TVS diode is further optimized. By constructing an additional low-impedance ESD discharge path, the ESD clamping voltage is significantly optimized, improving the system-level ESD and surge protection effect. This solves the typical problems of poor common-mode filter performance and the deterioration of ESD and surge clamping voltage caused by adding TVS diodes in the prior art.

[0054] The specific embodiments described above are preferred embodiments of the present invention and are not intended to limit the specific scope of the present invention. The scope of the present invention includes, but is not limited to, these specific embodiments. All equivalent changes made in accordance with the present invention are within the protection scope of the present invention.

Claims

1. A multifunctional broadband common-mode filter, characterized in that: The system includes an integrated common-mode filter and an electrostatic discharge (ESD) protection module. The common-mode filter includes a coupled inductor with common-mode rejection capability, which is composed of multiple coupled inductors. The ESD protection module contains multiple ESD protection devices and at least one inductor. The ESD protection devices and inductors in the ESD protection module constitute a series LC resonant circuit with common-mode rejection capability. The coupled inductor and the ESD protection module further constitute a broadband series LC resonant circuit with broadband common-mode rejection capability. The multiple ESD protection devices in the ESD protection module consist of three ESD protection devices, and each pair of adjacent ESD protection devices is coupled to form a low-impedance ESD discharge path.

2. The multifunctional broadband common-mode filter according to claim 1, characterized in that: The coupling inductor in the common-mode filter is replaced by a single-stage series LC resonant circuit or a multi-stage series LC resonant circuit. The single-stage series LC resonant circuit or the multi-stage series LC resonant circuit can further form a broadband series LC resonant circuit with broadband common-mode rejection capability with the electrostatic protection module.

3. The multifunctional broadband common-mode filter according to any one of claims 1 or 2, characterized in that: The common-mode filter is manufactured using one or more of the following processes: microwave transmission line, thin-film inductor, three-dimensional integrated inductor, bond wire coupling, and silicon integrated inductor.

4. The multifunctional broadband common-mode filter according to claim 3, characterized in that: The inductors in the common-mode filter and the electrostatic protection module are planar spiral structures. The planar spiral structure is constructed using various through-hole structures to create a three-dimensional 3D inductor structure. The multiple inductors in the common-mode filter can be formed into the coupled inductor by stacking multiple layers of metal.

5. The multifunctional broadband common-mode filter according to claim 4, characterized in that: The electrostatic discharge protection device is one or more of the following: diode, diode string, avalanche diode, Schottky diode, ESD protection array, Zener diode, bipolar transistor, NPN transistor, PNP transistor, silicon controlled rectifier, and field-effect transistor. The manufacturing process of the electrostatic discharge protection device is either a planar manufacturing process or a vertical manufacturing process.

6. The multifunctional broadband common-mode filter according to claim 5, characterized in that: The common-mode filter and the electrostatic protection module are manufactured using one or more of the following processes: BCD three-in-one monolithic integration process, nanoscale complementary metal-oxide-semiconductor process, RF CMOS radio frequency integrated circuit process, microstructure processing process, high voltage integrated circuit process, three-dimensional fin field-effect transistor process, all-around gate transistor process, silicon-germanium process, and silicon growth process on insulating substrate.

7. The multifunctional broadband common-mode filter according to claim 6, characterized in that: The connection methods for the common-mode filter and the electronic components in the electrostatic protection module include one or more of the following: packaged bonding wire, redistribution layer (RDL), metal via (VIA), through silicon via (TSV), glass via (TGV), PCB metal trace, flip-chip interconnect, copper pillar bump interconnect, micro-bump interconnect, redistribution layer bump interconnect, interlayer metal interconnect, wafer-level metal interconnect, heterogeneous integration interconnect, leadframe interconnect, conductive adhesive interconnect, copper damask interconnect, and hybrid bonding.

8. The multifunctional broadband common-mode filter according to claim 7, characterized in that: It can be used for broadband common-mode filtering of various port combinations, including I / O port and ground port GND, power port and I / O port, power port and ground port, I / O port and I / O port, signal port and signal port, RF port and ground port, analog port and digital port, sensor port and ground port, drive port and load port, chip core port and I / O port, bus port and ground port, and communication port and ground port.

9. The multifunctional broadband common-mode filter according to claim 8, characterized in that: The layout of the common-mode filter and the electrostatic protection module includes one or more of the following: strip semiconductor layout, ring semiconductor layout, pie semiconductor layout, interdigitated semiconductor layout, comb semiconductor layout, polygon semiconductor layout, circular semiconductor layout, elliptical semiconductor layout, fan-shaped semiconductor layout, grid semiconductor layout, array semiconductor layout, island semiconductor layout, strip interlaced semiconductor layout, ring nested semiconductor layout, polygonal symmetrical semiconductor layout, and irregular symmetrical semiconductor layout.

10. The multifunctional broadband common-mode filter according to claim 9, characterized in that: The electrostatic discharge protection module adopts an "asymmetric" structure that can protect against negative static electricity.

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