An electrostatic protection circuit

Abstract

The present invention discloses an electrostatic protection circuit. The electrostatic protection circuit includes: a first node, a second node, a first conduction module, a clamping module, a second conduction module, a third conduction module, a fourth conduction module, a fifth conduction module and a ground terminal; the first conduction module is connected between a first port to be protected and the first node; the clamping module is connected between the first node and the second node; the second conduction module is connected between the second node and a second port to be protected; the first port to be protected, the first conduction module, the clamping module, the second conduction module and the second port to be protected form a first current path; the third conduction module is connected between the second port to be protected and the first node; the fourth conduction module is connected between the second node and the first port to be protected; the second port to be protected, the third conduction module, the clamping module, the fourth conduction module and the first port to be protected form a second current path. The technical solution of the present invention can preferably achieve electrostatic protection.

Description

Technical Field

[0001] The present invention relates to the technical field of electrostatic protection, and particularly to an electrostatic protection circuit. Background Art

[0002] Vehicles are generally equipped with a controller, which can communicate with devices on the vehicle through a bus. For example, it can communicate with a motor controller or a battery manager on the vehicle, and can also communicate with windows, lights, rearview mirrors, etc. on the vehicle. The bus can include a Local Interconnect Network (LIN) bus or a Controller Area Network (CAN) bus.

[0003] In order to improve the security of communication or power supply, it is necessary to provide electrostatic protection for the bus port or the power supply port, that is, Electro-Static Discharge (ESD) protection. Some in-vehicle chips cannot be provided with Transient Voltage Suppressors (TVS) for electrostatic protection according to the test standard.

[0004] The prior art generally provides multiple clamping triodes (such as PNP triodes) for electrostatic protection. However, the area of the clamping triodes is large, resulting in a large occupied area of the electrostatic protection circuit. Moreover, when two or more PNP triodes are connected in series, the clamping voltage is large, which may damage the electrostatic protection circuit or the communication port and cannot protect the communication port or the power supply port well. Summary of the Invention

[0005] The present invention provides an electrostatic protection circuit to solve the problems that the electrostatic protection circuit occupies a large area and cannot protect the communication port or the power supply port well.

[0006] The present invention provides an electrostatic protection circuit, which includes: a first node, a second node, a first conduction module, a clamping module, a second conduction module, a third conduction module, a fourth conduction module, a fifth conduction module, and a ground terminal;

[0007] The first conduction module is connected between a first port to be protected and the first node;

[0008] The clamping module is connected between the first node and the second node;

[0009] The second conduction module is connected between the second node and the second port to be protected; wherein, the first port to be protected, the first conduction module, the clamping module, the second conduction module, and the second port to be protected form a first current path; the first port to be protected and the second port to be protected are different ports of the same chip;

[0010] The third conduction module is connected between the second port to be protected and the first node;

[0011] The fourth conduction module is connected between the second node and the first port to be protected; wherein, the second port to be protected, the third conduction module, the clamping module, the fourth conduction module, and the first port to be protected form a second current path;

[0012] The first end of the fifth conduction module is connected to the second node, and the second end of the fifth conduction module is connected to the ground terminal; wherein, the first port to be protected, the first conduction module, the clamping module, the fifth conduction module, and the ground terminal form a third current path; the second port to be protected, the third conduction module, the clamping module, the fifth conduction module, and the ground terminal form a fourth current path.

[0013] Optionally, the first port to be protected is a communication input port, and the second port to be protected is a communication output port; or, the first port to be protected is a positive power supply port, and the second port to be protected is a negative power supply port.

[0014] Optionally, the first end of the first conduction module is connected to the first port to be protected;

[0015] The first end of the clamping module is connected to the second end of the first conduction module at the first node, and the control end of the clamping module is connected to the first end of the clamping module;

[0016] The first end of the second conduction module is connected to the second end of the clamping module at the second node, and the second end of the second conduction module is connected to the second port to be protected;

[0017] The first end of the third conduction module is connected to the second port to be protected, and the second end of the third conduction module is connected to the first node;

[0018] The first end of the fourth conduction module is connected to the second node, and the second end of the fourth conduction module is connected to the first port to be protected.

[0019] Optionally, the electrostatic protection circuit further includes a sixth conduction module;

[0020] The first end of the sixth conduction module is connected to the ground terminal, and the second end of the sixth conduction module is connected to the first node; wherein, the ground terminal, the sixth conduction module, the clamping module, the fourth conduction module, and the first port to be protected form a fifth current path; the ground terminal, the sixth conduction module, the clamping module, the second conduction module, and the second port to be protected form a sixth current path.

[0021] Optionally, the first conduction module includes a first diode, a first pole of the first diode is electrically connected to the first port to be protected, and a second pole of the first diode is electrically connected to the first node;

[0022] The clamping module includes a clamping transistor, a first pole of the clamping transistor is electrically connected to the first node, a second pole of the clamping transistor is electrically connected to the second node, and a control pole of the clamping transistor is electrically connected to the first node;

[0023] The second conduction module includes a second diode, a first pole of the second diode is electrically connected to the second node, and a second pole of the second diode is electrically connected to the second port to be protected;

[0024] The third conduction module includes a third diode, a first pole of the third diode is electrically connected to the second port to be protected, and a second pole of the third diode is electrically connected to the first node;

[0025] The fourth conduction module includes a fourth diode, a first pole of the fourth diode is electrically connected to the second node, and a second pole of the fourth diode is electrically connected to the first port to be protected.

[0026] Optionally, the clamping transistor includes a triode or a field effect transistor.

[0027] Optionally, the first diode, the second diode, the third diode, and the fourth diode are electrostatic diodes;

[0028] The clamping transistor includes an electrostatic triode.

[0029] Optionally, the fifth conduction module includes a fifth diode, a first pole of the fifth diode is electrically connected to the second node, and a second pole of the fifth diode is electrically connected to the ground terminal;

[0030] The sixth conduction module includes a sixth diode, a first pole of the sixth diode is electrically connected to the ground terminal, and a second pole of the sixth diode is electrically connected to the first node.

[0031] Optionally, the electrostatic protection circuit further includes: a seventh conduction module and an eighth conduction module;

[0032] The first end of the seventh conduction module is connected to the power supply port, and the second end of the seventh conduction module is connected to the first node; wherein, the power supply port, the seventh conduction module, the clamping module, the fourth conduction module, and the first port to be protected form a seventh current path; the power supply port, the seventh conduction module, the clamping module, the second conduction module, and the second port to be protected form an eighth current path;

[0033] The first end of the eighth conduction module is connected to the ground terminal, and the second end of the eighth conduction module is connected to the power supply port; wherein, the first port to be protected, the first conduction module, the clamping module, the fifth conduction module, the eighth conduction module, and the power supply port form a ninth current path; the second port to be protected, the third conduction module, the clamping module, the fifth conduction module, the eighth conduction module, and the power supply port form a tenth current path.

[0034] Optionally, the seventh conduction module includes a seventh diode, a first pole of the seventh diode is electrically connected to the power supply port, and a second pole of the seventh diode is electrically connected to the first node;

[0035] The eighth conduction module includes an eighth diode, a first pole of the eighth diode is electrically connected to the ground terminal, and a second pole of the eighth diode is electrically connected to the power supply port.

[0036] In the technical solution of the embodiment of the present invention, when the first port to be protected and the second port to be protected are subjected to a positive electrostatic stress, a first current path formed by the first port to be protected, the first conduction module, the clamping module, the second conduction module, and the second port to be protected is conducted to form a current loop, so that the electrostatic current between the first port to be protected and the second port to be protected is released. When the first port to be protected and the second port to be protected are subjected to a negative electrostatic stress, a second current path formed by the second port to be protected, the third conduction module, the clamping module, the fourth conduction module, and the first port to be protected is conducted to release the electrostatic current. When a positive electrostatic stress is applied between the first port to be protected and the ground terminal, a third current path formed by the first port to be protected, the first conduction module, the clamping module, the fifth conduction module, and the ground terminal is conducted to form a current path to release the electrostatic current. When a positive electrostatic stress is applied between the second port to be protected and the ground terminal, a fourth current path formed by the second port to be protected, the third conduction module, the clamping module, the fifth conduction module, and the ground terminal is conducted to form a current path to release the electrostatic current. Moreover, the first conduction module, the second conduction module, the third conduction module, the fourth conduction module, and the fifth conduction module are unidirectionally conductive, so that reverse voltage withstand can be achieved, and a large electrostatic voltage can be avoided from damaging the first port to be protected and the second port to be protected, achieving the effect of electrostatic protection. Moreover, the first conduction module, the second conduction module, the third conduction module, the fourth conduction module, and the fifth conduction module can be implemented by diodes, which can reduce the number of transistors used, thereby reducing the area of the electrostatic protection circuit, and can make the voltage between the first node and the second node not too large, and can better achieve the protection effect on the first port to be protected and the second port to be protected. The first port to be protected and the second port to be protected can be different ports of the same chip. Then, the electrostatic protection circuit of this embodiment can achieve electrostatic protection for different ports of the same chip, realizing more comprehensive protection and can better achieve electrostatic protection.

[0037] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 is a schematic structural diagram of an electrostatic protection circuit in the related art;

[0040] Figure 2 is a schematic structural diagram of an electrostatic protection circuit provided by an embodiment of the present invention;

[0041] Figure 3 is a schematic structural diagram of another electrostatic protection circuit provided by an embodiment of the present invention;

[0042] Figure 4 is a schematic structural diagram of another electrostatic protection circuit provided by an embodiment of the present invention;

[0043] Figure 5 is a schematic structural diagram of another electrostatic protection circuit provided by an embodiment of the present invention;

[0044] Figure 6 is a schematic structural diagram of another electrostatic protection circuit provided by an embodiment of the present invention. Detailed implementation manners

[0045] In order to enable those skilled in the art to better understand the solution of 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 in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0046] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order different from those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0047] Figure 1 is a schematic structural diagram of an electrostatic protection circuit in the related art, as Figure 1As shown in the figure, the first port 1 is connected to the collector of the first triode P1. The base of the first triode P1 is connected to the emitter of the first triode P1. The emitter of the first triode P1 is connected to the emitter of the second triode P2. The base of the second triode P2 is connected to the emitter of the second triode P2. The collector of the second triode P2 is grounded. The power supply VDD is grounded through the third triode P3. The second port 2 is connected to the collector of the fourth triode P4. The base of the fourth triode P4 is connected to the emitter of the fourth triode P4. The emitter of the fourth triode P4 is connected to the emitter of the fifth triode P5. The base of the fifth triode P5 is connected to the emitter of the fifth triode P5. The collector of the fifth triode P5 is grounded. In this way, the first port 1, the first triode P1, the second triode P2 and the ground can form a current loop to release the static charges of the first port 1. The power supply VDD, the third triode P3 and the ground can form a current loop to release the static charges of the power supply VDD. The second port 2, the fourth triode P4, the fifth triode P5 and the ground can form a current path to release the static charges of the second port 2. However, in the related art, the number of triodes in the electrostatic protection circuit is large, resulting in a large area of the electrostatic protection circuit. Moreover, the first triode P1 and the second triode P2 are connected in series, resulting in a large clamping voltage. A higher voltage may damage the first port 1. Similarly, it may damage the second port 2, and it is impossible to achieve good electrostatic protection.

[0048] In view of the above technical problems, an embodiment of the present invention provides an electrostatic protection circuit. Figure 2 is a schematic structural diagram of an electrostatic protection circuit provided by an embodiment of the present invention. Refer to Figure 2 , the electrostatic protection circuit includes: a first node A1, a second node A2, a first conduction module 101, a clamping module 102, a second conduction module 103, a third conduction module 104, a fourth conduction module 105, a fifth conduction module 106 and a ground terminal GND;

[0049] The first conduction module 101 is connected between the first port to be protected B1 and the first node A1;

[0050] The clamping module 102 is connected between the first node A1 and the second node A2;

[0051] The second conduction module 103 is connected between the second node A2 and the second port to be protected B2. Among them, the first port to be protected B1, the first conduction module 101, the clamping module 102, the second conduction module 103 and the second port to be protected B2 form a first current path L1; the first port to be protected B1 and the second port to be protected B2 are different ports of the same chip;

[0052] The third conduction module 104 is connected between the second port to be protected B2 and the first node A1;

[0053] The fourth conduction module 105 is connected between the second node A2 and the first port to be protected B1; wherein, the second port to be protected B2, the third conduction module 104, the clamping module 102, the fourth conduction module 105, and the first port to be protected B1 form a second current path L2;

[0054] The first end of the fifth conduction module 106 is connected to the second node A2, and the second end of the fifth conduction module 106 is connected to the ground terminal GND; wherein, the first port to be protected B1, the first conduction module 101, the clamping module 102, the fifth conduction module 106, and the ground terminal GND form a third current path L3; the second port to be protected B2, the third conduction module 104, the clamping module 102, the fifth conduction module 106, and the ground terminal GND form a fourth current path L4.

[0055] Wherein, the first conduction module 101 can be a unidirectional conduction module, for example, it can include a diode. The second conduction module 103 can be a unidirectional conduction module, for example, it can include a diode. The third conduction module 104 can be a unidirectional conduction module, for example, it can include a diode. The fourth conduction module 105 can be a unidirectional conduction module, for example, it can include a diode. The fifth conduction module 106 is a unidirectional conduction module, for example, it can include a diode. The sixth conduction module 107 is a unidirectional conduction module, for example, it can include a diode. The ground terminal GND is grounded. The clamping module 102 can implement voltage clamping to clamp the voltage between the first node A1 and the second node A2. The clamping module 102 can include a triode or a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). The first port to be protected B1 and the second port to be protected B2 can be different ports of the same chip, for example, the input port and the output port of the same communication chip, or the input port and the output port of the same control chip. The first port to be protected B1 is the input port, and the second port to be protected B2 is the output port; or, the first port to be protected B1 is the output port, and the second port to be protected B2 is the input port, which is not limited in this embodiment. Or they are the positive power supply port and the negative power supply port of the same power supply chip. The first port to be protected B1 is the positive power supply port, and the second port to be protected B2 is the negative power supply port; or, the first port to be protected B1 is the negative power supply port, and the second port to be protected B2 is the positive power supply port, which is not limited in this embodiment.

[0056] Among them, the first current path L1 can be used as a path for current to flow, but it does not mean that a current path is formed. When the first conduction module 101, the clamping module 102, and the second conduction module 103 are turned on, the first current path L1 can form a current path, that is, a current loop is formed. Similarly, the second current path L2 can be used as a path for current to flow, but it does not mean that a current path is formed. When the third conduction module 104, the clamping module 102, and the fourth conduction module 105 are turned on, the second current path L2 can form a current path, that is, a current loop is formed. Similarly, the third current path L3 and the fourth current path L4 can be used as paths for current to flow.

[0057] Specifically, when the first port to be protected B1 and the second port to be protected B2 are subjected to a positive electrostatic stress, that is, when there is a positive static charge at the first port to be protected B1 or a negative static charge at the second port to be protected B2, the electrostatic voltage is relatively large, causing the first conduction module 101, the clamping module 102, and the second conduction module 103 to turn on. Then, the first current path L1 formed by the first port to be protected B1, the first conduction module 101, the clamping module 102, the second conduction module 103, and the second port to be protected B2 is turned on, forming a current loop, so that the electrostatic current between the first port to be protected B1 and the second port to be protected B2 is released. When the first port to be protected B1 and the second port to be protected B2 are subjected to a negative electrostatic stress, that is, when there is a negative static charge at the first port to be protected B1 or a positive static charge at the second port to be protected B2, the electrostatic voltage is relatively large, causing the third conduction module 104, the clamping module 102, and the fourth conduction module 105 to turn on, making the second current path L2 formed by the second port to be protected B2, the third conduction module 104, the clamping module 102, the fourth conduction module 105, and the first port to be protected B1 turn on, forming a current loop, so that the electrostatic current between the first port to be protected B1 and the second port to be protected B2 is released. In this way, the static charges of the first port to be protected B1 and the second port to be protected B2 can be released, thereby avoiding damage to the first port to be protected B1 and the second port to be protected B2 caused by a large electrostatic current, achieving the effect of electrostatic protection.

[0058] When a positive electrostatic stress is applied between the first port to be protected B1 and the ground terminal GND, the first conduction module 101 conducts, the clamping module 102 conducts, and the fifth conduction module 106 conducts. Then, the third current path L3 formed by the first port to be protected B1, the first conduction module 101, the clamping module 102, the fifth conduction module 106, and the ground terminal GND conducts, forming a current path to release the electrostatic current. When a positive electrostatic stress is applied between the second port to be protected B2 and the ground terminal GND, the third conduction module 104 conducts, the clamping module 102 conducts, and the fifth conduction module 106 conducts. Then, the fourth current path L4 formed by the second port to be protected B2, the third conduction module 104, the clamping module 102, the fifth conduction module 106, and the ground terminal GND conducts, forming a current path to release the electrostatic current.

[0059] Moreover, the first conduction module 101, the second conduction module 103, the third conduction module 104, and the fourth conduction module 105 are unidirectional conduction. The first conduction module 101 can enable the first port to be protected B1 to have a negative voltage withstand with respect to the first node A1, and the fourth conduction module 105 can enable the first port to be protected B1 to have a positive voltage withstand with respect to the second node A2. The third conduction module 104 can enable the second port to be protected B2 to have a negative voltage withstand with respect to the first node A1, and the second conduction module 103 can enable the second port to be protected B2 to have a positive voltage withstand with respect to the second node A2. In this way, a large electrostatic voltage can be prevented from damaging the first port to be protected B1 and the second port to be protected B2, achieving the effect of electrostatic protection. Moreover, the fifth conduction module 106 can achieve the negative voltage withstand of the first port to be protected B1 and the second port to be protected B2 with respect to the ground terminal GND, preventing a large electrostatic voltage from damaging the first port to be protected B1 and the second port to be protected B2, achieving the effect of electrostatic protection.

[0060] Furthermore, since the first conduction module 101, the second conduction module 103, the third conduction module 104, the fourth conduction module 105, and the fifth conduction module 106 are unidirectional conduction, it can be achieved by using diodes, which can reduce the number of transistors used, thereby reducing the area of the electrostatic protection circuit. Moreover, the voltage between the first node A1 and the second node A2 will not be large, which can better achieve the protection effect on the first port to be protected B1 and the second port to be protected B2. The first port to be protected B1 and the second port to be protected B2 can be different ports of the same chip. Then, the electrostatic protection circuit of this embodiment can achieve electrostatic protection for different ports of the same chip, realizing more comprehensive protection and better achieving electrostatic protection. It can not only achieve electrostatic protection between the first port to be protected B1 and the second port to be protected B2, but also achieve electrostatic protection between the first port to be protected B1 and the ground terminal GND, and can also achieve electrostatic protection between the second port to be protected B2 and the ground terminal GND.

[0061] In addition, when performing an electrostatic test between the first port to be protected B1 and the second port to be protected B2, it can be achieved through the first conduction module 101, the clamping module 102, and the second conduction module 103, or through the third conduction module 104, the clamping module 102, and the fourth conduction module 105, that is, it can be achieved through one clamping module 102 and two unidirectional conduction modules, thereby reducing the number and area of components required for the test.

[0062] In the technical solution of this embodiment, when the first port to be protected and the second port to be protected are subjected to a positive electrostatic stress, the first current path formed by the first port to be protected, the first conduction module, the clamping module, the second conduction module, and the second port to be protected is conducted, forming a current loop, so that the electrostatic current between the first port to be protected and the second port to be protected is released. When the first port to be protected and the second port to be protected are subjected to a negative electrostatic stress, the second current path formed by the second port to be protected, the third conduction module, the clamping module, the fourth conduction module, and the first port to be protected is conducted to release the electrostatic current. When a positive electrostatic stress is applied between the first port to be protected and the ground terminal, the third current path formed by the first port to be protected, the first conduction module, the clamping module, the fifth conduction module, and the ground terminal is conducted, forming a current path, to release the electrostatic current. When a positive electrostatic stress is applied between the second port to be protected and the ground terminal, the fourth current path formed by the second port to be protected, the third conduction module, the clamping module, the fifth conduction module, and the ground terminal is conducted, forming a current path, to release the electrostatic current. Moreover, the first conduction module, the second conduction module, the third conduction module, the fourth conduction module, and the fifth conduction module are unidirectional conduction, so that reverse voltage withstand can be achieved, and a large electrostatic voltage can be avoided from damaging the first port to be protected and the second port to be protected, achieving the effect of electrostatic protection. Moreover, the first conduction module, the second conduction module, the third conduction module, the fourth conduction module, and the fifth conduction module can be implemented by diodes, which can reduce the number of transistors used, thereby reducing the area of the electrostatic protection circuit, and the voltage between the first node and the second node will not be large, and the protection effect on the first port to be protected and the second port to be protected can be better achieved. The first port to be protected and the second port to be protected can be different ports of the same chip, then the electrostatic protection circuit of this embodiment can achieve electrostatic protection for different ports of the same chip, achieving more comprehensive protection and better realizing electrostatic protection.

[0063] Based on the above technical solution, optionally, the first port to be protected B1 is a communication input port, and the second port to be protected B2 is a communication output port; or, the first port to be protected B1 is a positive power supply port, and the second port to be protected B2 is a negative power supply port.

[0064] Specifically, in some embodiments, the first port to be protected B1 is a communication input port, and the second port to be protected B2 is a communication output port. Then, the electrostatic protection circuit of this embodiment can perform electrostatic protection on the input and output ports of the control chip or the communication chip, enabling the control chip or the communication chip to operate more stably and reliably. The communication input port can be a LIN bus communication input port, and the communication output port can be a LIN bus communication output port. Alternatively, the communication input port can be a CAN bus communication input port, and the communication output port is a CAN bus communication output port. This embodiment does not make any limitations in this regard.

[0065] In some embodiments, the first port to be protected B1 is a positive power supply port, and the second port to be protected B2 is a negative power supply port. Then, the electrostatic protection circuit of this embodiment can perform electrostatic protection on the ports of the power supply circuit or the power supply chip, ensuring the reliability and stability of power supply.

[0066] Optionally, as Figure 2 shown, the first end of the first conduction module 101 is connected to the first port to be protected B1;

[0067] The first end of the clamping module 102 is connected to the second end of the first conduction module 101 at the first node A1, and the control end of the clamping module 102 is connected to the first end of the clamping module 102;

[0068] The first end of the second conduction module 103 is connected to the second end of the clamping module 102 at the second node A2, and the second end of the second conduction module 103 is connected to the second port to be protected B2;

[0069] The first end of the third conduction module 104 is connected to the second port to be protected B2, and the second end of the third conduction module 104 is connected to the first node A1;

[0070] The first end of the fourth conduction module 105 is connected to the second node A2, and the second end of the fourth conduction module 105 is connected to the first port to be protected B1.

[0071] Specifically, when the first port to be protected B1 and the second port to be protected B2 are subjected to a positive electrostatic stress, that is, when there is a positive electrostatic charge at the first port to be protected B1 or a negative electrostatic charge at the second port to be protected B2, the potential at the first end of the first conduction module 101 is greater than the potential at the second end of the first conduction module 101, and the voltage difference between the first end and the second end of the first conduction module 101 is relatively large, and the first conduction module 101 conducts. The potential at the first end of the clamping module 102 is greater than the potential at the second end of the clamping module 102, and the voltage difference between the first end and the second end of the clamping module 102 is relatively large, and the clamping module 102 conducts. Similarly, the potential at the first end of the second conduction module 103 is greater than the potential at the second end of the second conduction module 103, and the voltage difference between the first end and the second end of the second conduction module 103 is relatively large, and the second conduction module 103 conducts. In this way, the first current path L1 forms a current path to release the electrostatic current.

[0072] When the first port to be protected B1 and the second port to be protected B2 are subjected to a negative electrostatic stress, that is, when there is a negative electrostatic charge at the first port to be protected B1 or a positive electrostatic charge at the second port to be protected B2, the potential at the first end of the third conduction module 104 is greater than the potential at the second end of the third conduction module 104, and the voltage difference between the first end and the second end of the third conduction module 104 is relatively large, and the third conduction module 104 conducts. The potential at the first end of the clamping module 102 is greater than the potential at the second end of the clamping module 102, and the voltage difference between the first end and the second end of the clamping module 102 is relatively large, and the clamping module 102 conducts. Similarly, the potential at the first end of the fourth conduction module 105 is greater than the potential at the second end of the fourth conduction module 105, and the voltage difference between the first end and the second end of the fourth conduction module 105 is relatively large, and the fourth conduction module 105 conducts. In this way, the second current path L2 forms a current path to release the electrostatic current.

[0073] Based on the above technical solutions, Figure 3 is a schematic structural diagram of another electrostatic protection circuit provided by an embodiment of the present invention. Optionally, referring to Figure 3 the electrostatic protection circuit further includes a sixth conduction module 107;

[0074] The first end of the sixth conduction module 107 is connected to the ground terminal GND, and the second end of the sixth conduction module 107 is connected to the first node A1; wherein, the ground terminal GND, the sixth conduction module 107, the clamping module 102, the fourth conduction module 105, and the first port to be protected B1 form a fifth current path L5; the ground terminal GND, the sixth conduction module 107, the clamping module 102, the second conduction module 103, and the second port to be protected B2 form a sixth current path L6.

[0075] Wherein, the sixth conduction module 107 is a unidirectional conduction module, for example, it may include a diode.

[0076] Specifically, when a negative electrostatic stress is applied between the first port to be protected B1 and the ground terminal GND, the sixth conduction module 107 conducts, the clamping module 102 conducts, the fourth conduction module 105 conducts, and the fifth current path L5 formed by the ground terminal GND, the sixth conduction module 107, the clamping module 102, the fourth conduction module 105, and the first port to be protected B1 conducts, forming a current path to release the electrostatic current. When a negative electrostatic stress is applied between the second port to be protected B2 and the ground terminal GND, the sixth conduction module 107 conducts, the clamping module 102 conducts, the second conduction module 103 conducts, and the sixth current path L6 formed by the ground terminal GND, the sixth conduction module 107, the clamping module 102, the second conduction module 103, and the second port to be protected B2 conducts, forming a current path to release the electrostatic current.

[0077] Moreover, the sixth conduction module 107 can be implemented by a diode, which can reduce the number of triodes and reduce the area of the electrostatic protection circuit.

[0078] In this way, the electrostatic protection circuit of this embodiment can achieve electrostatic protection between the first port to be protected B1 and the second port to be protected B2, can also achieve electrostatic protection between the first port to be protected B1 and the ground terminal GND, and can also achieve electrostatic protection between the second port to be protected B2 and the ground terminal GND.

[0079] Based on the above technical solutions, Figure 4 is a schematic structural diagram of another electrostatic protection circuit provided by an embodiment of the present invention. Optionally, referring to Figure 4 , the first conduction module 101 includes a first diode D1. The first pole of the first diode D1 is electrically connected to the first port to be protected B1, and the second pole of the first diode D1 is electrically connected to the first node A1;

[0080] The clamping module 102 includes a clamping transistor Q1. The first pole of the clamping transistor Q1 is electrically connected to the first node A1, the second pole of the clamping transistor Q1 is electrically connected to the second node A2, and the control pole of the clamping transistor Q1 is electrically connected to the first node A1;

[0081] The second conduction module 103 includes a second diode D2. The first pole of the second diode D2 is electrically connected to the second node A2, and the second pole of the second diode D2 is electrically connected to the second port to be protected B2.

[0082] The third conduction module 104 includes a third diode D3. The first pole of the third diode D3 is electrically connected to the second port to be protected B2, and the second pole of the third diode D3 is electrically connected to the first node A1.

[0083] The fourth conduction module 105 includes a fourth diode D4. The first pole of the fourth diode D4 is electrically connected to the second node A2, and the second pole of the fourth diode D4 is electrically connected to the first port to be protected B1.

[0084] Among them, the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 can be ordinary diodes or electrostatic diodes, which are not limited in this embodiment. The electrostatic diode is an Electro-Static discharge (ESD) diode, which is an electrostatic protection diode and a device used to protect electronic components from electrostatic discharge damage. An ordinary diode is a semiconductor device composed of a PN structure.

[0085] Specifically, for example, if the first pole of the first diode D1 is the anode and the second pole of the first diode D1 is the cathode, when there is a positive electrostatic charge at the first port to be protected B1, the first diode D1 can conduct unidirectionally and release the electrostatic current to the first node A1. The potential of the first node A1 is relatively high, so that the clamping transistor Q1 can conduct, and then release the electrostatic current to the second node A2. For example, if the first pole of the second diode D2 is the anode and the second pole of the second diode D2 is the cathode, when there is an electrostatic charge at the second node A2, the second diode D2 conducts and transmits the electrostatic current to the second port to be protected B2, so that the first current path forms a circuit and releases the electrostatic current.

[0086] For example, if the first pole of the third diode D3 is the anode and the second pole of the third diode D3 is the cathode, when there is a positive electrostatic charge at the second port to be protected B2, the third diode D3 conducts and releases the electrostatic current to the first node A1. The potential of the first node A1 is relatively high, so that the clamping transistor Q1 can conduct, and then release the electrostatic current to the second node A2. For example, if the first pole of the fourth diode D4 is the anode and the second pole of the fourth diode D4 is the cathode, when there is an electrostatic charge at the second node A2, the fourth diode D4 conducts and transmits the electrostatic current to the first port to be protected B1, so that the second current path forms a circuit and releases the electrostatic current.

[0087] Optionally, the clamping transistor Q1 includes a bipolar transistor or a field-effect transistor.

[0088] Specifically, the field-effect transistor is a MOS transistor. When the clamping transistor Q1 includes a bipolar transistor, the bipolar transistor can limit the voltage between its emitter and collector to a fixed value, that is, the potential between the first pole and the second pole of the clamping transistor Q1 is limited to a fixed value, so as to achieve a clamping effect and ensure that the voltage between the first node A1 and the second node A2 will not be too large, avoiding damage to the first protected port B1 and the second protected port. Similarly, when the MOS transistor works, it can limit the voltage between its source and drain to a fixed value, that is, the potential between the first pole and the second pole of the clamping transistor Q1 is limited to a fixed value, so as to achieve a clamping effect.

[0089] Optionally, the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 are electrostatic diodes; the clamping transistor Q1 includes an electrostatic bipolar transistor. In this way, the first diode D1, the second diode D2, the third diode D3, the fourth diode D4, and the clamping transistor Q1 can have a lower capacitance value and a fast response time, and can better withstand electrostatic current, making the electrostatic protection circuit more reliable.

[0090] Optionally, referring to Figure 4 , the fifth conduction module 106 includes a fifth diode D5. The first pole of the fifth diode D5 is electrically connected to the second node A2, and the second pole of the fifth diode D5 is electrically connected to the ground terminal GND;

[0091] The sixth conduction module 107 includes a sixth diode D6. The first pole of the sixth diode D6 is electrically connected to the ground terminal GND, and the second pole of the sixth diode D6 is electrically connected to the first node A1.

[0092] Among them, the fifth diode D5 and the sixth diode D6 can be ordinary diodes or electrostatic diodes, which are not limited in this embodiment.

[0093] Specifically, for example, the first pole of the fifth diode D5 is the anode, and the second pole of the fifth diode D5 is the cathode. For example, the first pole of the sixth diode D6 is the anode, and the second pole of the sixth diode D6 is the cathode. When a positive electrostatic stress is applied between the first port to be protected B1 and the ground terminal GND, the first diode D1 conducts, the clamping transistor Q1 conducts, and the fifth diode D5 conducts. Then, the third current path L3 formed by the first port to be protected B1, the first diode D1, the clamping transistor Q1, the fifth diode D5, and the ground terminal GND conducts, forming a current path to release the electrostatic current. When a positive electrostatic stress is applied between the second port to be protected B2 and the ground terminal GND, the third diode D3 conducts, the clamping transistor Q1 conducts, and the fifth diode D5 conducts. Then, the fourth current path L4 formed by the second port to be protected B2, the third diode D3, the clamping transistor Q1, the fifth diode D5, and the ground terminal GND conducts, forming a current path to release the electrostatic current.

[0094] When a negative electrostatic stress is applied between the first port to be protected B1 and the ground terminal GND, the sixth diode D6 conducts, the clamping transistor Q1 conducts, and the fourth diode D4 conducts. Then, the fifth current path L5 formed by the ground terminal GND, the sixth diode D6, the clamping transistor Q1, the fourth diode D4, and the first port to be protected B1 conducts, forming a current path to release the electrostatic current. When a negative electrostatic stress is applied between the second port to be protected B2 and the ground terminal GND, the sixth diode D6 conducts, the clamping transistor Q1 conducts, and the second diode D2 conducts. Then, the sixth current path L6 formed by the ground terminal GND, the sixth diode D6, the clamping transistor Q1, the second diode D2, and the second port to be protected B2 conducts, forming a current path to release the electrostatic current.

[0095] Optionally, the fifth diode D5 and the sixth diode D6 are electrostatic diodes. In this way, they can better withstand the electrostatic current and achieve a better electrostatic protection effect.

[0096] Based on the above technical solutions, Figure 5 is a schematic structural diagram of another electrostatic protection circuit provided by an embodiment of the present invention. Optionally, referring to Figure 5 , the electrostatic protection circuit further includes: a seventh conduction module 108 and an eighth conduction module 109;

[0097] The first end of the seventh conduction module 108 is connected to the power supply port V1, and the second end of the seventh conduction module 108 is connected to the first node A1; wherein, the power supply port V1, the seventh conduction module 108, the clamping module 102, the fourth conduction module 105, and the first port to be protected B1 form a seventh current path L7; the power supply port V1, the seventh conduction module 108, the clamping module 102, the second conduction module 103, and the second port to be protected B2 form an eighth current path L8;

[0098] The first end of the eighth conduction module 109 is connected to the ground terminal GND, and the second end of the eighth conduction module 109 is connected to the power supply port V1; wherein, the first port to be protected B1, the first conduction module 101, the clamping module 102, the fifth conduction module 106, the eighth conduction module 109, and the power supply port V1 form a ninth current path L9; the second port to be protected B2, the third conduction module 104, the clamping module 102, the fifth conduction module 106, the eighth conduction module 109, and the power supply port V1 form a tenth current path L10.

[0099] Wherein, the seventh conduction module 108 is, for example, a unidirectional conduction module and may include, for example, a diode. The eighth conduction module 109 is, for example, a unidirectional conduction module and may include, for example, a diode. The power supply port V1 is connected to a power supply voltage.

[0100] Specifically, when a positive electrostatic stress is applied between the first port to be protected B1 and the power supply port V1, the first conduction module 101, the clamping module 102, the fifth conduction module 106, and the eighth conduction module 109 conduct, so that the ninth current path L9 forms a current path, thereby releasing the electrostatic current. When a positive electrostatic stress is applied between the second port to be protected B2 and the power supply port V1, the third conduction module 104, the clamping module 102, the fifth conduction module 106, and the eighth conduction module 109 conduct, so that the tenth current path L10 forms a current path, thereby releasing the electrostatic current. When a negative electrostatic stress is applied between the first port to be protected B1 and the power supply port V1, the seventh conduction module 108, the clamping module 102, and the fourth conduction module 105 conduct, so that the seventh current path L7 forms a current path, thereby releasing the electrostatic current. When a negative electrostatic stress is applied between the second port to be protected B2 and the power supply port V1, the seventh conduction module 108, the clamping module 102, and the second conduction module 103 conduct, so that the eighth current path L8 forms a current path, thereby releasing the electrostatic current.

[0101] Moreover, the seventh conduction module 108 can achieve the voltage withstand of the first port to be protected B1 and the second port to be protected B2 with respect to the power supply port V1, thereby avoiding damage to the first port to be protected B1 and the second port to be protected B2 caused by a large electrostatic voltage, achieving the effect of electrostatic protection.

[0102] Moreover, the seventh conduction module 108 and the eighth conduction module 109 can be implemented by diodes, thereby reducing the number of triodes, decreasing the area of the electrostatic protection circuit, and reducing the voltage between the first node A1 and the second node A2, achieving a better electrostatic protection effect.

[0103] In this way, the electrostatic protection circuit of this embodiment can simultaneously perform electrostatic protection on the first port to be protected B1, the second port to be protected B2, the power supply port V1, and the ground terminal GND, achieving a comprehensive protection effect.

[0104] Based on the above technical solution, Figure 6 is a schematic structural diagram of another electrostatic protection circuit provided by an embodiment of the present invention. Optionally, referring to Figure 6 , the seventh conduction module 108 includes a seventh diode D7. The first pole of the seventh diode D7 is electrically connected to the power supply port V1, and the second pole of the seventh diode D7 is electrically connected to the first node A1;

[0105] The eighth conduction module 109 includes an eighth diode D8. The first pole of the eighth diode D8 is electrically connected to the ground terminal GND, and the second pole of the eighth diode D8 is electrically connected to the power supply port V1.

[0106] Among them, the seventh transistor D7 and the eighth transistor D8 can be ordinary diodes or electrostatic diodes, which are not limited in this embodiment.

[0107] Specifically, for example, if the first pole of the seventh transistor D7 is the anode and the second pole of the seventh transistor D7 is the cathode, then the seventh transistor D7 can achieve unidirectional conduction and reverse voltage resistance, thereby achieving an electrostatic protection effect. For example, if the first pole of the eighth transistor D8 is the anode and the second pole of the eighth transistor D8 is the cathode, then the eighth transistor D8 can achieve unidirectional conduction and reverse voltage resistance, thereby achieving an electrostatic protection effect.

[0108] When a positive electrostatic stress is applied between the first protected port B1 and the power supply port V1, the first diode D1, the clamping transistor Q1, the fifth diode D5, and the eighth diode D8 conduct, enabling the ninth current path L9 to form a current path, thereby releasing the electrostatic current. When a positive electrostatic stress is applied between the second protected port B2 and the power supply port V1, the third diode D3, the clamping transistor Q1, the fifth diode D5, and the eighth diode D8 conduct, enabling the tenth current path L10 to form a current path, thereby releasing the electrostatic current. When a negative electrostatic stress is applied between the first protected port B1 and the power supply port V1, the seventh diode D7, the clamping diode Q1, and the fourth diode D4 conduct, enabling the seventh current path L7 to form a current path, thereby releasing the electrostatic current. When a negative electrostatic stress is applied between the second protected port B2 and the power supply port V1, the seventh diode D7, the clamping transistor Q1, and the second diode D2 conduct, enabling the eighth current path L8 to form a current path, thereby releasing the electrostatic current.

[0109] Optionally, the seventh diode D7 and the eighth diode D8 are electrostatic diodes. In this way, the electrostatic current can be better tolerated, the breakdown voltage can be better achieved, and a better electrostatic protection effect can be obtained.

[0110] The above specific embodiments do not limit the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electrostatic protection circuit, characterized in that: include: A first node, a second node, a first conduction module, a clamping module, a second conduction module, a third conduction module, a fourth conduction module, a fifth conduction module and a ground terminal; The first conduction module is connected between the first port to be protected and the first node; The clamping module is connected between the first node and the second node; The second conduction module is connected between the second node and the second port to be protected; wherein the first port to be protected, the first conduction module, the clamping module, the second conduction module and the second port to be protected form a first current path; the first port to be protected and the second port to be protected are different ports of the same chip; The third conduction module is connected between the second port to be protected and the first node; The fourth conducting module is connected between the second node and the first port to be protected; wherein the second port to be protected, the third conducting module, the clamping module, the fourth conducting module and the first port to be protected form a second current path; The first end of the fifth conduction module is connected to the second node, and the second end of the fifth conduction module is connected to the ground terminal; wherein the first port to be protected, the first conduction module, the clamping module, the fifth conduction module and the ground terminal form a third current path; the second port to be protected, the third conduction module, the clamping module, the fifth conduction module and the ground terminal form a fourth current path; The electrostatic protection circuit further includes: a seventh conduction module; The first end of the seventh conduction module is connected to the power port, and the second end of the seventh conduction module is connected to the first node; wherein the power port, the seventh conduction module, the clamping module, the fourth conduction module and the first port to be protected form a seventh current path; the power port, the seventh conduction module, the clamping module, the second conduction module and the second port to be protected form an eighth current path; The electrostatic protection circuit further includes: an eighth conduction module; The first end of the eighth conductive module is connected to the ground end, and the second end of the eighth conductive module is connected to the power port; wherein, the first port to be protected, the first conductive module, the clamping module, the fifth conductive module, the eighth conductive module and the power port form a ninth current path; the second port to be protected, the third conductive module, the clamping module, the fifth conductive module, the eighth conductive module and the power port form a tenth current path.

2. The electrostatic protection circuit according to claim 1, characterized in that: The first port to be protected is a communication input port, and the second port to be protected is a communication output port; or, the first port to be protected is a positive power port, and the second port to be protected is a negative power port.

3. The electrostatic protection circuit according to claim 1, characterized in that: The first end of the first conduction module is connected to the first port to be protected; The first end of the clamp module and the second end of the first conduction module are connected to a first node, and the control end of the clamp module is connected to the first end of the clamp module; The first end of the second conducting module and the second end of the clamping module are connected to a second node, and the second end of the second conducting module is connected to the second port to be protected; A first end of the third conductive module is connected to the second port to be protected, and a second end of the third conductive module is connected to the first node; A first end of the fourth conducting module is connected to the second node, and a second end of the fourth conducting module is connected to the first port to be protected.

4. The electrostatic protection circuit according to claim 1, characterized in that: The electrostatic protection circuit further includes a sixth conduction module; The first end of the sixth conduction module is connected to the ground end, and the second end of the sixth conduction module is connected to the first node; wherein the ground end, the sixth conduction module, the clamping module, the fourth conduction module and the first port to be protected form a fifth current path; the ground end, the sixth conduction module, the clamping module, the second conduction module and the second port to be protected form a sixth current path.

5. The electrostatic protection circuit according to claim 1, characterized in that: The first conduction module includes a first diode, a first electrode of the first diode is electrically connected to the first port to be protected, and a second electrode of the first diode is electrically connected to the first node; The clamp module comprises a clamp transistor, a first electrode of the clamp transistor is electrically connected to the first node, a second electrode of the clamp transistor is electrically connected to the second node, and a control electrode of the clamp transistor is electrically connected to the first node; The second conduction module includes a second diode, a first electrode of the second diode is electrically connected to the second node, and a second electrode of the second diode is electrically connected to the second port to be protected; The third conduction module includes a third diode, a first electrode of the third diode is electrically connected to the second port to be protected, and a second electrode of the third diode is electrically connected to the first node; The fourth conduction module includes a fourth diode, a first electrode of the fourth diode is electrically connected to the second node, and a second electrode of the fourth diode is electrically connected to the first port to be protected.

6. The electrostatic protection circuit according to claim 5, characterized in that: The clamping transistor includes a triode or a field effect transistor.

7. The electrostatic protection circuit according to claim 5, characterized in that: The first diode, the second diode, the third diode and the fourth diode are electrostatic diodes; The clamping transistor includes an electrostatic triode.

8. The electrostatic protection circuit according to claim 4, characterized in that: The fifth conduction module comprises a fifth diode, a first electrode of the fifth diode is electrically connected to the second node, and a second electrode of the fifth diode is electrically connected to the ground terminal; The sixth conduction module includes a sixth diode, a first electrode of the sixth diode is electrically connected to the ground terminal, and a second electrode of the sixth diode is electrically connected to the first node.

9. The electrostatic protection circuit according to claim 1, characterized in that: The seventh conduction module includes a seventh diode, a first electrode of the seventh diode is electrically connected to the power port, and a second electrode of the seventh diode is electrically connected to the first node; The eighth conduction module includes an eighth diode, a first electrode of the eighth diode is electrically connected to the ground terminal, and a second electrode of the eighth diode is electrically connected to the power port.

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