ESD electrostatic protection isolation circuit and ESD electrostatic protection isolation device

Abstract

The utility model relates to the technical field of circuit ESD protection, and provides an ESD electrostatic protection isolation circuit and an ESD electrostatic protection isolation device, the ESD electrostatic protection isolation circuit comprises a common mode inductor, a first protection unit, a second protection unit, a signal input end and a signal output end; one end of the first protection unit is electrically connected with one end of the common mode inductor, and the other end of the first protection unit is electrically connected with a signal input end; one end of the second protection unit is electrically connected with the other end of the common mode inductor, and the other end of the second protection unit is electrically connected with the signal output end; the first protection unit and the second protection unit are symmetrically arranged on the two sides of the common mode inductor, so that the problem of forward crosstalk of ESD can be effectively solved, interference of ESD can be prevented in the reverse direction, meanwhile, signals can be filtered, and signal crosstalk caused by other external signals is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit ESD protection, and more specifically to an ESD electrostatic protection isolation circuit and an ESD electrostatic protection isolation device. Background Art

[0002] ESD (Electro-Static Discharge) can cause damage and destruction to electronic equipment products. Therefore, electrostatic protection has become an important part of electronic equipment product quality control. In the prior art, ESD (Electrostatic Discharge) electrostatic protection circuits are usually used for ports that need to be connected to some external devices. In the existing ESD electrostatic protection circuit design, most of them directly use transient suppression diodes and capacitors to filter GND (ground terminal). GND (ground terminal) is generally interconnected, and static electricity will pass through the crosstalk of GND (ground terminal), skip the transient suppression diode and capacitor, and thus cannot effectively isolate ESD static electricity. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide an ESD electrostatic protection isolation circuit and an ESD electrostatic protection isolation device in view of the above-mentioned defects of the prior art.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] On the one hand, the utility model provides an ESD electrostatic protection isolation circuit, including a common-mode inductor, a first protection unit, a second protection unit, a signal input terminal and a signal output terminal; one end of the first protection unit is electrically connected to one end of the common-mode inductor, and the other end of the first protection unit is electrically connected to the signal input terminal; one end of the second protection unit is electrically connected to the other end of the common-mode inductor, and the other end of the second protection unit is electrically connected to the signal output terminal.

[0006] In some embodiments, the first protection unit includes a first transient suppression diode and a first capacitor; the first transient suppression diode and the first capacitor are connected in parallel between the common mode inductor and the signal input terminal.

[0007] In some embodiments, the first pin of the common-mode inductor is electrically connected to one end of the first capacitor, one end of the first transient suppression diode, and the positive electrode of the signal input terminal respectively; the second pin of the common-mode inductor is electrically connected to the other end of the first capacitor, the other end of the first transient suppression diode, and the negative electrode of the signal input terminal respectively.

[0008] In some embodiments, the second protection unit includes a second transient suppression diode and a second capacitor; the second transient suppression diode and the second capacitor are connected in parallel between the common mode inductor and the signal output terminal.

[0009] In some embodiments, the third pin of the common-mode inductor is electrically connected to one end of the second capacitor, one end of the second transient suppression diode, and the positive electrode of the signal output end respectively; the fourth pin of the common-mode inductor is electrically connected to the other end of the second capacitor, the other end of the second transient suppression diode, and the negative electrode of the signal output end respectively.

[0010] In some embodiments, the first capacitor and the second capacitor are both ceramic capacitors.

[0011] In some embodiments, the models of the first capacitor and the second capacitor are both CC0805KKX7R0BB105.

[0012] In some embodiments, the first TVS diode and the second TVS diode are both of model TEVD0R6V15B1X.

[0013] In some embodiments, the common mode inductor has a model number of TLDCM7035-2-102TF.

[0014] On the other hand, the utility model also provides an ESD electrostatic protection isolation device, comprising any of the ESD electrostatic protection isolation circuits described above.

[0015] The beneficial effect of the utility model is that, different from the prior art, in the ESD electrostatic protection isolation circuit of the utility model, one end of the first protection unit is electrically connected to one end of the common-mode inductor, and the other end of the first protection unit is electrically connected to the signal input end; one end of the second protection unit is electrically connected to the other end of the common-mode inductor, and the other end of the second protection unit is electrically connected to the signal output end; by symmetrically arranging the first protection unit and the second protection unit on both sides of the common-mode inductor, the forward crosstalk of ESD can be effectively solved, and the reverse interference of ESD can also be protected. At the same time, it can also filter the signal, reduce the signal crosstalk caused by other external signals, and effectively isolate the common-mode crosstalk of the signals of the front and rear stages and suppress the electrostatic ESD energy on a single line. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the circuit structure of the ESD electrostatic protection isolation circuit in the embodiment of the utility model;

[0017] Figure 2 It is a schematic diagram of the layout of the ESD electrostatic protection isolation circuit on the circuit board in the embodiment of the utility model. DETAILED DESCRIPTION

[0018] The terms "first", "second", "third" and "fourth" etc. in the specification and claims of the utility model and the drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0019] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0020] "Multiple" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the related objects are in an "or" relationship.

[0021] Moreover, the terms "up, down, front, back, left, right, upper end, lower end" etc. indicating directions are all based on the posture and position of the device or equipment described in this solution during normal use.

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the following will be described clearly and completely in combination with the technical solution in the embodiments of the utility model. Obviously, the described embodiments are partial embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the utility model.

[0023] The utility model is implemented as follows Figure 1 As shown in the figure, an ESD electrostatic protection isolation circuit includes a common-mode inductor L, a first protection unit 10, a second protection unit 20, a signal input terminal and a signal output terminal; one end of the first protection unit 10 is electrically connected to one end of the common-mode inductor L, and the other end of the first protection unit 10 is electrically connected to the signal input terminal; one end of the second protection unit 20 is electrically connected to the other end of the common-mode inductor L, and the other end of the second protection unit 20 is electrically connected to the signal output terminal.

[0024] Specifically, in this embodiment, the first protection unit 10 includes a first transient suppression diode TVS1 and a first capacitor C1; the first transient suppression diode TVS1 and the first capacitor C1 are connected in parallel between the common mode inductor L and the signal input terminal. Among them, the first pin of the common mode inductor L is electrically connected to one end of the first capacitor C1, one end of the first transient suppression diode TVS1 and the positive electrode Uin+ of the signal input terminal respectively; the second pin of the common mode inductor L is electrically connected to the other end of the first capacitor C1, the other end of the first transient suppression diode TVS1 and the negative electrode Uin- of the signal input terminal respectively. By using a first transient suppression diode TVS1 at the signal input terminal for protection first, and then filtering and absorbing through a first capacitor C1, effective filtering and crosstalk prevention are achieved.

[0025] Specifically, in this embodiment, the second protection unit 20 includes a second transient suppression diode TVS2 and a second capacitor C2; the second transient suppression diode TVS2 and the second capacitor C2 are connected in parallel between the common mode inductor L and the signal output terminal. Among them, the third pin of the common mode inductor L is electrically connected to one end of the second capacitor C2, one end of the second transient suppression diode TVS2 and the positive electrode Uout+ of the signal output terminal respectively; the fourth pin of the common mode inductor L is electrically connected to the other end of the second capacitor C2, the other end of the second transient suppression diode TVS2 and the negative electrode Uout- of the signal output terminal respectively. By using a second transient suppression diode TVS2 at the signal output terminal for protection first, and then filtering and absorbing through a second capacitor C2, effective filtering and crosstalk prevention can also be achieved.

[0026] In this embodiment, the first capacitor C1 and the second capacitor C2 are both ceramic capacitors, and the models of the first capacitor C1 and the second capacitor C2 are both CC0805KKX7R0BB105.

[0027] In this embodiment, the models of the first transient suppression diode TVS1 and the second transient suppression diode TVS2 are both TEVD0R6V15B1X.

[0028] In this embodiment, the model of the common mode inductor L is TLDCM7035-2-102TF.

[0029] It should be noted that the models of the corresponding devices in the ESD electrostatic protection isolation circuit of this embodiment and their corresponding parameters can be designed and selected according to actual application requirements. This embodiment is only an example and does not constitute a specific limitation, and should be based on actual application.

[0030] In the ESD electrostatic protection isolation circuit of the embodiment of the utility model, the first transient suppression diode TVS1 and the first capacitor C1 are symmetrically arranged on both sides of the common-mode inductor L with the second transient suppression diode TVS2 and the second capacitor C2. They are first protected by a transient suppression diode and then further filtered and absorbed by a capacitor. In the middle is the common-mode inductor L for isolation. Bidirectional protection and isolation are achieved based on the symmetrical circuit design, which can effectively solve the forward crosstalk of ESD and reversely protect against ESD interference. At the same time, it can also filter the signal and reduce the signal crosstalk caused by other external signals, so as to effectively realize the electrostatic isolation and protection of the circuit and the port.

[0031] In practical application, the ESD electrostatic protection isolation circuit in this embodiment needs to be arranged on a PCB (Printed Circuit Board). Its layout on the PCB is as follows: Figure 2 as shown in .

[0032] It should be noted that the ESD electrostatic protection isolation circuit in this embodiment can be well applied to any suitable circuit and port for electrostatic ESD or signal filtering isolation.

[0033] In another embodiment of the utility model, an ESD electrostatic protection isolation device is also provided, and the ESD electrostatic protection isolation device includes the ESD electrostatic protection isolation circuit provided in the above embodiment. For the introduction of the ESD electrostatic protection isolation circuit, please refer to the above embodiment, which will not be repeated here.

[0034] It should be understood that ordinary technical workers in the field can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to the utility model.

Claims

1. An ESD electrostatic protection isolation circuit, characterized in that: It includes a common-mode inductor, a first protection unit, a second protection unit, a signal input terminal and a signal output terminal; one end of the first protection unit is electrically connected to one end of the common-mode inductor, and the other end of the first protection unit is electrically connected to the signal input terminal; one end of the second protection unit is electrically connected to the other end of the common-mode inductor, and the other end of the second protection unit is electrically connected to the signal output terminal.

2. The ESD electrostatic protection isolation circuit according to claim 1, characterized in that: The first protection unit includes a first transient suppression diode and a first capacitor; the first transient suppression diode and the first capacitor are connected in parallel between the common mode inductor and the signal input terminal.

3. The ESD electrostatic protection isolation circuit according to claim 2, characterized in that: The first pin of the common-mode inductor is electrically connected to one end of the first capacitor, one end of the first transient suppression diode and the positive electrode of the signal input terminal respectively; the second pin of the common-mode inductor is electrically connected to the other end of the first capacitor, the other end of the first transient suppression diode and the negative electrode of the signal input terminal respectively.

4. The ESD electrostatic protection isolation circuit according to claim 3, characterized in that: The second protection unit includes a second transient suppression diode and a second capacitor; the second transient suppression diode and the second capacitor are connected in parallel between the common mode inductor and the signal output terminal.

5. The ESD electrostatic protection isolation circuit according to claim 4, characterized in that: The third pin of the common-mode inductor is electrically connected to one end of the second capacitor, one end of the second transient suppression diode and the positive electrode of the signal output end respectively; the fourth pin of the common-mode inductor is electrically connected to the other end of the second capacitor, the other end of the second transient suppression diode and the negative electrode of the signal output end respectively.

6. The ESD electrostatic protection isolation circuit according to claim 4 or 5, characterized in that: The first capacitor and the second capacitor are both ceramic capacitors.

7. The ESD electrostatic protection isolation circuit according to claim 4 or 5, characterized in that: The models of the first capacitor and the second capacitor are both CC0805KKX7R0BB105.

8. The ESD electrostatic protection isolation circuit according to claim 4 or 5, characterized in that: The models of the first transient suppression diode and the second transient suppression diode are both TEVD0R6V15B1X.

9. The ESD electrostatic protection isolation circuit according to any one of claims 1 to 5, characterized in that: The model of the common mode inductor is TLDCM7035-2-102TF.

10. An ESD electrostatic protection isolation device, characterized in that: It comprises the ESD electrostatic protection isolation circuit as described in any one of claims 1 to 9.

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