Surge protection chip and system

Abstract

The utility model provides a surge protection chip and system, and the chip comprises a base island, and the input end of the surge protection chip is connected to the base island through a first connecting piece. The input end of the integrated circuit module is connected to the base island, the output end of the integrated circuit module is connected with the output end of the surge protection chip, and the grounding end of the integrated circuit module is connected with the grounding end of the surge protection chip; the first end of the switching tube is connected to the base island, the second end is connected with the grounding end of the surge protection chip, and the third end is connected with the control end of the integrated circuit module; when the working voltage or current is smaller than the preset surge trigger threshold value, the output signal of the control end of the integrated circuit module is in a switch tube turn-off state; when the working voltage is larger than or equal to the preset surge trigger threshold value, an output signal of the control end of the integrated circuit module conducts the switch tube, and the first connecting piece can be fused. According to the technical scheme of the utility model, when surge occurs, the input end, the output end and the grounding end are in an open circuit state, the protection reliability is high, and the cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic components, and in particular to a surge protection chip and system. Background Art

[0002] According to statistics, a large part of electronic product failures are caused by transients and surges. Voltage transients and surges are everywhere. Power grids, lightning strikes, explosions, and even people walking on carpets can generate tens of thousands of volts of electrostatic induction voltage, which are invisible and fatal killers of electronic products. Therefore, in order to improve the reliability of electronic products and the safety of the human body, protective measures must be taken against voltage transients and surges.

[0003] The current protection measures include: connecting a TVS between Vin and GND of the protection chip to increase the surge level at the input end; this solution has the following two main disadvantages:

[0004] (1) Once the surge energy exceeds the TVS, the TVS breaks down into a short circuit state. At this time, the input end is short-circuited to the ground, causing damage to the input end; and when the wire on the TVS is blown, the surge energy directly acts on the protection chip of the subsequent stage. The protection chip will be broken down by the surge energy, showing a short circuit, and eventually the entire system is damaged;

[0005] The closed-circuit TVS solution completely relies on the characteristics of the TVS to enter the open-circuit failure mode. This is a passive protection that cannot effectively protect the subsequent chips and has a short-circuit phenomenon. Therefore, the reliability of surge protection capability is poor.

[0006] In addition, the DC withstand voltage of the protection chip depends entirely on the DC withstand voltage of the TVS; and the DC withstand voltage of the TVS is definitely lower than that of the subsequent chip, which leads to a low DC withstand voltage of the entire protection chip; (the subsequent chip can reach a DC withstand voltage of 40V, but in order for the TVS to have protection capabilities, the DC withstand voltage of the TVS must be less than 40V);

[0007] In fact, when the chip encounters a surge with large energy, the protection chip usually fails in a short-circuit mode. Once the protection chip is in a short-circuit mode, it cannot effectively protect the subsequent chips, and eventually the entire system will be damaged by the surge.

[0008] (2) The existing TVS surge protection solution takes up space on the PCB layout and increases costs.

[0009] Therefore, there is an urgent need to provide a new protection chip to solve the problems of poor reliability and high cost in the prior art. Utility Model Content

[0010] The utility model provides a surge protection chip and a system to solve the problems of poor surge protection reliability and high cost in the prior art.

[0011] In order to solve the above technical problems, the utility model is implemented through the following technical solutions:

[0012] According to a first aspect of the present invention, a surge protection chip is provided, comprising:

[0013] A base island, an input end of the surge protection chip is connected to the base island through a first connecting member;

[0014] An integrated circuit module, wherein an input end of the integrated circuit module is connected to the base island, an output end of the integrated circuit module is connected to an output end of the surge protection chip, and a ground end of the integrated circuit module is connected to a ground end of the surge protection chip;

[0015] A switch tube, wherein a first end of the switch tube is connected to the base island, a second end of the switch tube is connected to a ground terminal of the surge protection chip, and a third end of the switch tube is connected to a control terminal of the integrated circuit module;

[0016] When the operating voltage or current at the input end of the surge protection chip is less than a preset surge trigger threshold, the output signal at the control end of the integrated circuit module is in a state of turning off the switch tube;

[0017] When the operating voltage or current at the input end of the surge protection chip is greater than or equal to the preset surge trigger threshold, the output signal of the control end of the integrated circuit module turns on the switch tube, which can cause the first connector to fuse.

[0018] Preferably, the input end of the integrated circuit module is connected to the base island specifically by: the input end of the integrated circuit module is connected to the base island through a second connector;

[0019] The overcurrent capability of the first connection member is weaker than the overcurrent capability of the second connection member.

[0020] Preferably, there are multiple first connecting members.

[0021] Preferably, the integrated circuit module comprises: a control circuit, wherein the output end of the control circuit serves as the control end of the integrated circuit module;

[0022] Wherein, the control circuit comprises:

[0023] An input state detection circuit, used to detect the voltage or current at the input end of the integrated circuit module;

[0024] A reference circuit for providing a preset surge trigger threshold;

[0025] A comparison circuit, used to compare the detection value of the input state detection circuit with the preset surge trigger threshold value, and determine whether the voltage or current at the input end of the integrated circuit module is greater than or equal to the preset surge trigger threshold value;

[0026] A logic control circuit, used for outputting a control signal according to the judgment result of the comparison circuit;

[0027] The driving circuit is used to drive the switch tube to be turned off or on according to the control signal.

[0028] Preferably, the withstand voltage of the switch tube is greater than or equal to the withstand voltage of the integrated circuit module.

[0029] Preferably, the third end of the switch tube is connected to the ground end of the surge protection chip specifically in that: the third end of the switch tube is connected to the ground end of the surge protection chip through a third connecting member.

[0030] Preferably, the wire diameter of the second connecting member is greater than the first preset wire diameter value; and / or, the number of the second connecting members is multiple;

[0031] The wire diameter of the third connecting member is greater than the second preset wire diameter value; and / or, the number of the third connecting members is multiple.

[0032] Preferably, the switch tube and the integrated circuit module are integrated in the same package, which can further reduce the cost.

[0033] Preferably, the overcurrent capability of the first connecting member is weaker than the overcurrent capability of the third connecting member.

[0034] According to a second aspect of the utility model, there is provided a surge protection system, comprising: a package body, and a surge protection chip as described in any one of the above items;

[0035] The surge protection chip is packaged in the package body.

[0036] The surge protection chip and system provided by the utility model adopt the scheme of connecting the switch tube in parallel in the integrated circuit module. When the working voltage or current is greater than or equal to the preset surge trigger threshold, the first connector is fused, that is, the connection between the input end of the surge protection chip and the base island is disconnected. At this time, the input end of the surge protection chip is disconnected from all connections, and it is in an open circuit state with the output end and the grounding end, rather than a short circuit state. It can timely and accurately protect the subsequent circuit, prevent the chip from being in a short circuit failure mode and damaging the subsequent circuit, avoid the damage of the entire protection chip caused by the surge, and the surge protection reliability is high.

[0037] In addition, the failure mode of presenting an open circuit under surge simplifies the surge protection design and can effectively reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0039] Figure 1 A schematic diagram of a surge protection chip according to an embodiment of the present invention;

[0040] Figure 2 is a schematic diagram of a control circuit of an embodiment of the utility model;

[0041] Figure 3 A schematic diagram of a surge protection system according to an embodiment of the present invention;

[0042] Description of reference numerals:

[0043] 101-Key Island,

[0044] 102- integrated circuit module,

[0045] 103- switch tube;

[0046] 201 The input end of the surge protection chip,

[0047] 202- Output end of surge protection chip,

[0048] 203- ground terminal of surge protection chip;

[0049] 301- first connecting member,

[0050] 302- second connecting piece,

[0051] 303- third connecting piece,

[0052] 304- fourth connecting piece,

[0053] 305-fifth connecting piece;

[0054] 401-input status detection circuit,

[0055] 402-reference circuit,

[0056] 403-Comparison circuit,

[0057] 404-Logic control circuit,

[0058] 405-driving circuit,

[0059] 5-Package. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0061] In the description of the utility model specification, it is necessary to understand that the orientation or position relationship indicated by the terms "upper part", "lower part", "upper end", "lower end", "lower surface", "upper surface", etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0062] In the description of the utility model specification, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0063] In the description of the present invention, "plurality" means multiple, such as two, three, four, etc., unless otherwise clearly and specifically defined.

[0064] In the description of the utility model specification, unless otherwise clearly specified and limited, the term "connection" and other terms should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to specific circumstances.

[0065] The following specific embodiments are used to describe the technical solution of the utility model in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0066] For surge protection, the traditional solution is mainly to connect a TVS between Vin and GND of the protection chip. This solution has the following disadvantages:

[0067] Once the surge energy exceeds the TVS, the TVS will break down into a short circuit state. At this time, the input end is short-circuited to the ground, which will cause damage to the front-stage circuit of the protection chip input end; and when the wire on the TVS is melted, the surge energy directly acts on the protection chip, and the protection chip is also broken down by the surge energy, showing a short circuit, causing damage to the back-stage circuit of the protection chip; eventually the entire system is damaged;

[0068] The closed-circuit TVS solution completely relies on the characteristics of the TVS to enter the open-circuit failure mode. This is a passive protection that cannot effectively protect the subsequent chips and has a short-circuit phenomenon. Therefore, the reliability of surge protection capability is poor.

[0069] In addition, the DC withstand voltage of the protection chip depends entirely on the DC withstand voltage of the TVS; and the DC withstand voltage of the TVS is definitely lower than that of its subsequent chip, which leads to a low DC withstand voltage of the entire protection chip; (the subsequent chip can reach a DC withstand voltage of 40V, but in order for the TVS to have protection capabilities, the DC withstand voltage of the TVS must be less than 40V);

[0070] In fact, when the chip encounters a surge with large energy, the protection chip usually fails in a short-circuit mode. Once the protection chip is in short-circuit mode, it cannot effectively protect its subsequent chips, and eventually the entire system will be damaged by the surge.

[0071] In view of this, the present application provides a new surge protection chip, which includes: a base island 101, an integrated circuit module 102, and a switch tube 103, please refer to Figure 1 . Among them, the input terminal (VIN) 201 of the surge protection chip is connected to the base island 101 through the first connector 301; the input terminal Vin of the integrated circuit module 102 is connected to the base island 101, the output terminal Vout of the integrated circuit module 102 is connected to the output terminal (VOUT) 202 of the surge protection chip, and the ground terminal Gnd of the integrated circuit module 102 is connected to the ground terminal (GND) 203 of the surge protection chip. The first end of the switch tube 103 is connected to the base island (it can be connected by conductive glue, and the connection between the first end and the base island is not shown in the figure), the second end of the switch tube 103 is connected to the ground terminal 203 of the surge protection chip, and the third end of the switch tube 103 is connected to the control terminal GC of the integrated circuit module 102.

[0072] When the operating voltage or current of the input terminal 201 of the surge protection chip is less than the preset surge trigger threshold, the output signal of the control terminal of the integrated circuit module 102 is in a state of turning off the switch tube 103, the surge protection function does not work, and the integrated circuit module works normally; when the operating voltage or current of the input terminal 201 of the surge protection chip is greater than or equal to the preset surge trigger threshold, the output signal of the control terminal of the integrated circuit module 102 turns on the switch tube, which can cause the first connecting member to fuse.

[0073] In the surge protection chip of the present application, when a surge occurs, the first connector is first fused, the input terminal VIN of the surge protection chip is disconnected, and it is in an open circuit state with all other components and ports. The open circuit failure mode can prevent the protection chip from being in a short circuit failure mode and damaging the subsequent circuit; and both VIN and VOUT, as well as VIN and GND are in an open circuit state, and the protection reliability is high. In addition, the DC withstand voltage of the switch tube can be greater than or equal to the DC withstand voltage of the integrated circuit module, thereby ensuring that the DC withstand voltage of the surge protection chip is sufficient.

[0074] Furthermore, in the surge protection chip of the present application, the VIN end is connected to the GND end through a switch tube. When a surge occurs, the switch tube is turned on, and the surge energy on the VIN end is discharged through the switch tube. The discharge path of the surge energy is: VIN→switch tube→GND, which can ensure that the surge energy does not enter the integrated circuit module.

[0075] Practically, the switch tube 103 may be a MOS tube, the drain of the MOS tube serves as the first end of the switch tube, the source of the MOS tube serves as the second end of the switch tube, and the gate of the MOS tube serves as the third end of the switch tube.

[0076] Of course, in different embodiments, the switch tube 103 may also be a triode.

[0077] In one embodiment, the input terminal Vin of the integrated circuit module 102 is connected to the base island 101 specifically as follows: the input terminal Vin of the integrated circuit module 102 is connected to the base island through the second connector 302; the overcurrent capability of the first connector is weaker than the overcurrent capability of the second connector. It can be ensured that when a surge occurs, the first connector is blown first. In one embodiment, in order to ensure the overcurrent capability from the input terminal VIN of the surge protection chip to the switch tube 103 and the passing capability of normal current, the number of first connectors can be increased, that is, the number of first connectors is multiple.

[0078] Correspondingly, in order to ensure the overcurrent capacity of the second connector, the wire diameter of the second connector can be designed to be larger than the first preset wire diameter value. In addition, the number of the second connectors can be increased, that is, the number of the second connectors is multiple.

[0079] In one embodiment, the integrated circuit module includes: a control circuit, and the output end of the control circuit serves as the control end of the integrated circuit module. Figure 2 The control circuit includes: an input state detection circuit 401, a reference circuit 402, a comparison circuit 403, a logic control circuit 404 and a driving circuit 405.

[0080] Among them, the input end of the input state detection circuit 401 is connected to the input end of the integrated circuit module 102, and the output end is connected to an input end of the comparison circuit 403; it is used to detect the voltage or current of the input end of the integrated circuit module 102. The reference circuit 402 is connected to the other input end of the comparison circuit 403; the reference circuit is used to provide a preset surge trigger threshold. The output end of the comparison circuit 403 is connected to the input end of the logic control circuit 404; the comparison circuit 403 is used to compare the detection value of the input state detection circuit 401 with the preset surge trigger threshold, and determine whether the voltage or current of the input end of the integrated circuit module 102 is greater than or equal to the preset surge trigger threshold. The output end of the logic control circuit 404 is connected to the input end of the drive circuit 405; the logic control circuit 404 is used to output a control signal according to the judgment result of the comparison circuit 403; the output end of the drive circuit 405 is used as the control end of the integrated circuit module, connected to the third end of the switch tube; the drive circuit 405 is used to drive the switch tube to turn off or on according to the control signal.

[0081] In one embodiment, in order to prevent the surge protection chip from having insufficient withstand voltage, the switch tube is selected to have a withstand voltage greater than or equal to the withstand voltage of the integrated circuit module.

[0082] In one embodiment, the second end of the switch tube 103 is connected to the ground terminal GND of the surge protection chip specifically as follows: the second end of the switch tube 103 is connected to the ground terminal GND of the surge protection chip through the third connecting member 303 .

[0083] The third connector 303 is connected to the ground terminal GND of the surge protection chip. When a surge occurs, the discharge path of the surge energy is: VIN→first connector-switch tube-third connector-GND. The third connector 303 will pass a relatively large current. In order to prevent it from melting, the third connector can be designed to have a strong overcurrent capability, specifically: the wire diameter of the third connector 303 is designed to be larger than the second preset wire diameter value; and / or the number of the third connectors is designed to be multiple.

[0084] In one embodiment, the Gnd terminal of the integrated circuit module 102 may also be connected to the GND terminal through the third connecting member 303 .

[0085] In one embodiment, the Vout terminal of the integrated circuit module 102 can be connected to the VOUT of the surge protection chip through the fourth connector 304 , and the control terminal of the integrated circuit module 102 can be connected to the third terminal of the switch tube 103 through the fifth connector 305 .

[0086] In one embodiment, in order to further reduce the cost, the switch tube 103 and the integrated circuit module 102 may be integrated into the same package, that is, the switch tube 103 may be integrated inside the integrated circuit module.

[0087] In one embodiment, the overcurrent capability of the first connecting member may be designed to be weaker than the overcurrent capability of the third connecting member.

[0088] Practically, the connecting member in the above embodiment may be a wire bonding.

[0089] The following is an example of the wire selection of the first connector, the second connector, and the third connector:

[0090] The wire diameter of the first connector can be selected to have a higher impedance than the wire diameters of the second and third connectors. For example, the first connector can be selected to have a 0.6 mil copper wire, and the second and third connectors can be selected to have a 0.8 mil copper wire. In terms of quantity, in order to ensure the respective overcurrent capabilities, the number of wires in the first connector, the second connector, and the third connector can be multiple. Furthermore, in order to better ensure that the overcurrent capability of the first connector is weaker than that of the second and third connectors, the number of wires in the second and third connectors can be designed to be higher than the number of wires in the first connector.

[0091] Practically, the number of wires bonded to the first connector may be 2, such as including two 0.6 mil copper wires; the number of wires bonded to the second connector and the third connector may be 4, such as including four 0.8 mil copper wires.

[0092] In one embodiment, the overcurrent capability of the first connecting member may be designed to be weaker than the overcurrent capability of the fourth connecting member.

[0093] Practically, the fourth connector may also be made of 0.8 mil copper wire, and the number of wires bonded to the fourth connector may also be 4, that is, it includes four 0.8 mil copper wires.

[0094] In the above example, in order to reduce the cost of packaging wire bonding, the wires of the second connector, the third connector, and the fourth connector are of the same wire diameter. Of course, in different embodiments, the wire diameters of the second connector, the third connector, and the fourth connector may also be different.

[0095] Of course, it should be noted that the wire diameter and number of the above-mentioned wires are only examples. In different embodiments, the wire diameter and number of the wires can be selected differently according to actual needs, as long as the overcurrent capacity of the first connector is lower than the overcurrent capacity of the second connector, the third connector, and the fourth connector.

[0096] In one embodiment, in order to further reduce the packaging cost, the fifth connector can use a wire with the same wire diameter as the second connector, the third connector, and the fourth connector; for example, a 0.8 mil copper wire can be used; or the fifth connector can also use a wire with the same wire diameter as the first connector; for example, a 0.6 mil copper wire can be used. The above design ensures that there are only two wire diameters for the wire bonding, thereby reducing the packaging cost of the wire bonding.

[0097] In one embodiment, a surge protection system is also provided, which includes: a package body 5, a surge protection chip, and the surge protection chip is packaged in the package body 5. Please refer to Figure 3 Wherein, the surge protection chip is the surge protection chip described in any of the above embodiments.

[0098] In one embodiment, the surge protection chip further includes a functional PAD, which can be connected to a corresponding functional port on the package body by wire bonding.

[0099] In the description of this specification, the description with reference to the terms "an implementation", "an example", "a specific implementation process", "an example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A surge protection chip, characterized in that: include: A base island, an input end of the surge protection chip is connected to the base island through a first connecting member; An integrated circuit module, wherein an input end of the integrated circuit module is connected to the base island, an output end of the integrated circuit module is connected to an output end of the surge protection chip, and a ground end of the integrated circuit module is connected to a ground end of the surge protection chip; A switch tube, wherein a first end of the switch tube is connected to the base island, a second end of the switch tube is connected to a ground terminal of the surge protection chip, and a third end of the switch tube is connected to a control terminal of the integrated circuit module; When the operating voltage or current at the input end of the surge protection chip is less than a preset surge trigger threshold, the output signal at the control end of the integrated circuit module is in a state of turning off the switch tube; When the operating voltage or current at the input end of the surge protection chip is greater than or equal to the preset surge trigger threshold, the output signal of the control end of the integrated circuit module turns on the switch tube, which can cause the first connector to fuse.

2. The surge protection chip according to claim 1, characterized in that: The input end of the integrated circuit module is connected to the base island specifically: the input end of the integrated circuit module is connected to the base island through a second connector; The overcurrent capability of the first connection member is weaker than the overcurrent capability of the second connection member.

3. The surge protection chip according to claim 2, characterized in that: The wire diameter of the second connecting member is greater than the first preset wire diameter value; and / or, there are multiple second connecting members.

4. The surge protection chip according to claim 2, characterized in that: The number of the first connecting members is plural.

5. The surge protection chip according to claim 1, characterized in that: The integrated circuit module comprises: a control circuit, wherein the output end of the control circuit serves as the control end of the integrated circuit module; Wherein, the control circuit comprises: An input state detection circuit, used to detect the voltage or current at the input end of the integrated circuit module; A reference circuit for providing a preset surge trigger threshold; A comparison circuit, used to compare the detection value of the input state detection circuit with the preset surge trigger threshold value, and determine whether the voltage or current at the input end of the integrated circuit module is greater than or equal to the preset surge trigger threshold value; A logic control circuit, used for outputting a control signal according to the judgment result of the comparison circuit; The driving circuit is used to drive the switch tube to be turned off or on according to the control signal.

6. The surge protection chip according to claim 1, characterized in that: The withstand voltage of the switch tube is greater than or equal to the withstand voltage of the integrated circuit module.

7. The surge protection chip according to claim 1, characterized in that: The third end of the switch tube is connected to the ground end of the surge protection chip specifically: the third end of the switch tube is connected to the ground end of the surge protection chip through a third connecting member.

8. The surge protection chip according to claim 7, characterized in that: The wire diameter of the third connecting member is greater than the second preset wire diameter value; and / or, the number of the third connecting members is multiple.

9. The surge protection chip according to claim 7, characterized in that: The switch tube and the integrated circuit module are integrated in the same package.

10. The surge protection chip according to claim 9, characterized in that: The overcurrent capability of the first connection member is weaker than the overcurrent capability of the third connection member.

11. A surge protection system, characterized in that: include: A package body, and a surge protection chip as claimed in any one of claims 1 to 10; The surge protection chip is packaged in the package body.

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