CN215221019U

CN215221019U - Circuit and electronic equipment capable of realizing electrostatic protection of antenna end

Info

Publication number: CN215221019U
Application number: CN202121520356.XU
Authority: CN
Inventors: 夏杰; 吴晨雨; 刘宗金; 吴佳; 欧新华; 袁琼
Original assignee: Shanghai Xindao Electronic Technology Co ltd
Current assignee: Shanghai Xindao Electronic Technology Co ltd
Priority date: 2021-07-05
Filing date: 2021-07-05
Publication date: 2021-12-17
Anticipated expiration: 2031-07-05

Abstract

The utility model provides a can realize circuit and electronic equipment of antenna end electrostatic protection, include: the antenna is connected with the TVS tube unit, the first end of the TVS tube unit is directly or indirectly connected with the connecting end of the antenna, and the second end of the TVS tube unit is directly or indirectly grounded; the TVS tube unit comprises TVS tubes made of N semiconductors, wherein N is more than or equal to 2, and at least part of the TVS tubes are connected in series.

Description

Circuit and electronic equipment capable of realizing electrostatic protection of antenna end

Technical Field

The utility model relates to an electrostatic protection field of antenna especially relates to a circuit and electronic equipment that can realize antenna end electrostatic protection.

Background

In many electronic devices, an antenna is configured to transmit signals to the outside by using the antenna, and in the prior art, the signals that can be transmitted by the antenna are usually enhanced as much as possible, which can be realized by an internal circuit or by a structural design. On the basis, how to protect the antenna and the associated circuits becomes a problem which needs to be solved urgently.

In the related design, a conventional polymer ESD device (electrostatic Discharge, ESD) is usually used to protect the antenna, however, both the turn-on voltage of the conventional polymer ESD device and the clamp voltage formed by the conventional polymer ESD device are high, and the protection effect is not good.

SUMMERY OF THE UTILITY MODEL

The utility model provides a can realize antenna end electrostatic protection's circuit and electronic equipment to solve the not good problem of traditional polymer ESD device protection effect.

According to the utility model discloses an aspect provides a can realize circuit of antenna end electrostatic protection, include: the antenna is connected with the TVS tube unit, the first end of the TVS tube unit is directly or indirectly connected with the connecting end of the antenna, and the second end of the TVS tube unit is directly or indirectly grounded;

the TVS tube unit comprises TVS tubes made of N semiconductors, wherein N is more than or equal to 2, and at least part of the TVS tubes are connected in series.

Optionally, the N TVS tubes include N bidirectional TVS tubes connected in series, and a formed capacitance value is lower than 0.1 pF.

Optionally, the number of the TVS tubes is two.

Optionally, the capacitance values of the TVS tubes are the same.

Optionally, the circuit capable of achieving electrostatic protection of the antenna end further includes a filtering unit, and the filtering unit is connected between the connection end of the antenna and the first end of the TVS tube unit.

Optionally, the filtering unit includes a filtering inductor, a first filtering capacitor, and a second filtering capacitor;

the first end of filter inductance is connected the first end of TVS pipe unit, the second end of filter inductance is connected the link of antenna, first filter capacitor connect in between filter inductance's first end and ground, second filter capacitor connect in between filter inductance's second end and ground.

Optionally, the first filter capacitor and the second filter capacitor are both variable capacitors.

Optionally, the circuit capable of realizing the electrostatic protection of the antenna end further includes a capacitor and a grounding inductor; the capacitor is connected between the first end of the TVS tube unit and the connecting end of the antenna, and the connecting end of the antenna is grounded through the grounding inductor.

According to a second aspect of the present invention, there is provided an electronic device including a circuit capable of realizing electrostatic protection of an antenna terminal, to which the first aspect and the optional scheme thereof relate.

Optionally, the electronic device includes a metal frame, and the antenna is connected to the metal frame.

The utility model provides a can realize circuit and electronic equipment of antenna end electrostatic protection, adopted the TVS pipe unit that contains two at least TVS pipes (it is made for the semiconductor), and then the electrostatic protection of antenna is realized to accessible TVS pipe, wherein, based on the device characteristic of TVS pipe, the turn-on voltage of TVS pipe and the clamping voltage that forms are all lower, compare in traditional polymer ESD device, can play more excellent protection effect, in addition, because the utility model discloses a plurality of TVS pipes (N is more than or equal to 2), and at least partial TVS pipe series connection, can help further reducing the holistic appearance value of a plurality of TVS pipes, it can accomplish at least to be less than 0.2pF (in the concrete scheme, a plurality of TVS pipes of N of establishing ties can ensure that the appearance value is less than 0.1 pF). The reduction of the capacitance value is beneficial to the impedance matching of the antenna, the lower conduction voltage of the TVS tube is beneficial to the discharge of ESD energy, and the smaller clamping voltage can be realized.

It can be seen that the utility model discloses can control ESD's residual voltage lower, still can have on-resistance, on-voltage is little, the leakage current is low, advantage such as response speed is fast, still can prevent accident's when guaranteeing the normal work of system line.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a first schematic circuit diagram of a circuit capable of implementing electrostatic protection at an antenna end according to an embodiment of the present invention;

FIG. 2 is a TLP view of a TVS tube made of a semiconductor;

fig. 3 is a second schematic circuit diagram of a circuit capable of implementing electrostatic protection at an antenna end according to an embodiment of the present invention;

fig. 4 is a third schematic circuit diagram of a circuit capable of implementing electrostatic protection at an antenna end according to an embodiment of the present invention;

fig. 5 is a fourth schematic circuit diagram of a circuit capable of implementing electrostatic protection at an antenna end according to an embodiment of the present invention;

fig. 6 is a fifth schematic circuit diagram of a circuit capable of implementing electrostatic protection at an antenna end according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.

Description of reference numerals:

1-TVS tube unit;

2-an antenna;

3-a filtering unit;

4-a metal frame;

5-an electronic device;

c1 — first filter capacitance;

c2 — second filter capacitance;

c3-capacitance;

l1-filter inductance;

l-ground inductance.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprising" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions.

The technical solution of the present invention will be described in detail with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

The embodiment of the utility model provides a related antenna can be for the antenna of the arbitrary signal of transmission, and transmission wherein can indicate to send and/or receive, and this signal can be the signal of arbitrary form, frequency, content, no matter what kind of antenna is applied to, all do not break away from the utility model discloses the scope of embodiment.

Referring to fig. 1 to 7, an embodiment of the present invention provides a circuit capable of implementing antenna end electrostatic protection, including: an antenna 2 and a TVS tube unit 1.

The TVS specifically includes: the Transient Voltage Suppressor is understood to be: a transient voltage suppressor diode.

The first end of the TVS tube unit 1 is directly or indirectly connected to the connection end (in some embodiments, it may also be understood as a common end) of the antenna 2, and the second end of the TVS tube unit 1 is directly or indirectly grounded.

The TVS tube unit 1 comprises N TVS tubes, wherein N is more than or equal to 2, at least part of the TVS tubes are connected in series, and the volume value formed by the N TVS tubes is lower than 1pF, further lower than 0.13pF, and still further lower than 0.1 pF.

Wherein, the value of 0.1pF can be understood as: it is not (or hardly) possible to reduce the TVS capacitance below 0.1pF in the semiconductor limit process.

Furthermore, the embodiment of the utility model provides a break through the use custom to the TVS pipe among the prior art (the common custom adopts single TVS pipe), to in the segmentation field of protecting to the antenna, formed the TVS pipe of establishing ties (for example two string formula TVS place mode), under the condition of the TVS pipe that adopts limit appearance value, the embodiment of the utility model provides a can help breaking through the limit of single TVS pipe appearance value to the electrostatic protection effect has further been improved.

The N TVS transistors may be integrated or may be discrete devices. In the illustrated example, all N TVS tubes are connected in series, and further, the first end of the TVS tube unit 1 is connected in series, and the second end of the TVS tube unit 2 is connected in series.

In the illustrated example, the N TVS tubes include N bidirectional TVS tubes connected in series, when N is 2, two TVS tubes connected in series may be, for example, a first bidirectional TVS tube TVS1 and a second bidirectional TVS tube TVS2 as shown in the figure.

In other not illustrated examples, the embodiment of the present invention does not exclude the scheme of adopting three or more than three TVS pipes, and when adopting a greater number of TVS pipes, each TVS pipe may be in series connection, and there may also be a parallel connection between a partial TVS pipe and another partial TVS pipe.

In the illustrated example, the TVS tube unit 1 is directly grounded, and in other examples, the scheme that the TVS tube unit 1 is grounded after being connected in series with other devices (such as a resistor) is not excluded.

In the illustrated example, the capacitance values of the TVS tubes are the same, and further, taking two TVS tubes with the same capacitance value as an example, the capacitance value formed may be half of the capacitance value of a single TVS tube. For example: the two-string TVS placement scheme can reduce the capacitance by half (for example, if the capacitance of a single TVS tube is 0.1pF, the capacitance of two TVS tubes is 0.1pF/2 ═ 0.05pF as a whole).

Specifically, the reduction principle of the capacity value may be, for example:

the capacitance C is k epsilon S/d;

wherein:

k is dielectric constant

ε S total area

d is the distance between the polar plates;

on the basis, the total area of the TVS tubes after being connected in series is unchanged, the distance is increased by 2 times, and further, the capacity is reduced to a half. Impedance matching is required to be carried out on materials placed in the antenna section, and if the volume value of the placed TVS is too large, impedance matching of the whole wire diameter is affected. After the series connection, a smaller (for example, less than one time) capacitance value can be obtained, which is more favorable for impedance matching.

In another example, the capacitance of each TVS tube may be different.

In order to more clearly show the difference and effect between the polymer ESD device and the TVS transistor made of semiconductor, the following description will be made based on the parameters of the exemplified polymer ESD device and TVS transistor made of semiconductor.

Parameters of the polymer ESD device may be, for example:

it can be seen that the typical value of the turn-on voltage is 450V, and the typical value of the clamping voltage is 40V, and according to the parameters of the polymer ESD device, the turn-on voltage of the polymer ESD device is found to be higher, the clamping voltage is higher, and the ESD protection effect capability is limited. Furthermore, impedance matching is too difficult in the case of polymer-based ESD devices.

The parameters of the TVS tube may be, for example:

it can be seen that typical values for the turn-on voltage therein may be, for example, 7.5V, wherein typical values for the clamp voltage may be, for example, 26V;

wherein, V_BRCan be correspondingly regarded as V in the foregoing_T

The results of the test using Transmission Line Pulses (TLP) are shown in fig. 2, with 16A corresponding to an ESD of 8kV (i.e. electrostatic discharge).

From the comparative data, it can be seen that the parameters of the polymer ESD are larger than those of the TVS transistor made of semiconductor, regardless of the turn-on voltage or the clamp voltage.

Therefore, the TVS made of semiconductor can control the residual voltage of ESD to be lower, and has the characteristics of fast response speed (for example, less than 25nS), small on-resistance and on-voltage, low leakage current (for example, up to 1 μ a), and the like.

In one embodiment, referring to fig. 3, the circuit capable of implementing electrostatic protection at an antenna end further includes a filter unit 3, and the filter unit 3 is connected between the connection end of the antenna 2 and the first end of the TVS tube unit 1.

The filtering unit 3 may be any device or combination of devices capable of achieving a filtering function, and in a specific embodiment, the filtering unit 3 may also be regarded as a circuit unit that achieves functions of impedance matching, resonance, and the like.

In an example, referring to fig. 4 and fig. 6, the filter unit 3 includes a filter inductor L1, a first filter capacitor C1, and a second filter capacitor C2.

The first end of the filter inductor L1 is connected to the first end of the TVS tube unit 1, the second end of the filter inductor L1 is connected to the connection end of the antenna 2, the first filter capacitor C1 is connected between the first end of the filter inductor L1 and ground, and the second filter capacitor C2 is connected between the second end of the filter inductor L1 and ground.

At least one of the first filter capacitor C1 and the second filter capacitor C2 may be a variable capacitor. In the example shown in fig. 6, the first filter capacitor C1 and the second filter capacitor C2 are both variable capacitors, and the first filter capacitor C1 and the second filter capacitor C2 are directly grounded. In the embodiment not shown, other devices (e.g., inductors) may be disposed between the first filter capacitor C1 and the ground and between the second filter capacitor C2 and the ground.

In one embodiment, referring to fig. 5 and fig. 6, the circuit capable of implementing electrostatic protection at an antenna end further includes a capacitor C3 and a grounding inductor L2; the capacitor C3 is connected between the first end of the TVS tube unit 1 and the connection end of the antenna 2, and the connection end of the antenna 2 is grounded through the grounding inductor L2.

In some schemes, electric capacity C3 can play the effect of resonance, and in some schemes, electric capacity C3 can play the effect of isolation, according to the change of lectotype and application scene, its effect can change to, no matter how change, all do not break away from the utility model discloses the scope of embodiment.

In addition to the above-mentioned exemplary circuits, other circuit portions with various functions such as impedance matching, filtering, resonance, isolation, etc. may be disposed between the TVS tube unit and the antenna, and in addition, the first end of the TVS tube unit may be further connected to a circuit portion with a signal amplification function (i.e., the antenna may be connected to the circuit portion with the signal amplification function), and whether the circuit portion with the signal amplification function is adopted or not, the first end of the TVS tube unit may be further finally connected to a processing module of the MCU or the CPU (i.e., the antenna may be connected to the processing module).

The embodiment of the present invention further provides an electronic device (for example, the electronic device 5 shown in fig. 7), which includes a circuit related to the first aspect and the optional scheme thereof and capable of implementing the antenna end electrostatic protection.

The electronic device may be any device that requires an antenna, such as a mobile phone, a tablet computer, a vehicle-mounted terminal, or any other terminal.

In a further aspect, the trace design of many antennas connects the antenna to a metal bezel of an electronic device (e.g., a mobile phone, a tablet computer, etc.), which is advantageous for signal enhancement. However, since this type of design is frequently in contact with a person, it is imperative that the ESD capability be introduced into the electronic device through the antenna wires, which is a major threat to the electronic device (e.g., a mobile phone sensitive to this).

On this basis, the clamping voltage protective capability of traditional polymer ESD device can't satisfy chip tolerance ability such as CPU, MCU of present high integrated level, so will cause the damage of chip absolutely, adopt the embodiment of the utility model relates to behind the scheme, can effectively reduce this kind of damage.

In some embodiments, the electronic device includes a metal frame 4, and the antenna is connected to the metal frame 4. The technical effects mentioned above when the TVS tube unit is adopted can be fully shown under the scheme. Simultaneously, the utility model discloses the scheme also can be applied to the scheme that does not adopt metal framework 4.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. A circuit capable of realizing electrostatic protection of an antenna terminal is characterized by comprising: the antenna is connected with the TVS tube unit, the first end of the TVS tube unit is directly or indirectly connected with the connecting end of the antenna, and the second end of the TVS tube unit is directly or indirectly grounded;

2. The circuit capable of achieving antenna end esd protection as claimed in claim 1, wherein the N TVS transistors include N bidirectional TVS transistors connected in series, and the capacitance value is lower than 0.1 pF.

3. The circuit capable of achieving antenna end electrostatic protection according to claim 1, wherein the number of the TVS transistors is two.

4. The circuit capable of achieving antenna end electrostatic protection according to claim 1, wherein the capacitance values of the TVS transistors are the same.

5. The circuit capable of realizing electrostatic protection of an antenna end according to any one of claims 1 to 4, further comprising a filter unit, wherein the filter unit is connected between the connection end of the antenna and the first end of the TVS tube unit.

6. The circuit capable of achieving antenna end electrostatic protection according to claim 5, wherein the filter unit includes a filter inductor, a first filter capacitor and a second filter capacitor;

7. The circuit capable of achieving antenna end electrostatic protection according to claim 6, wherein at least one of the first filter capacitor and the second filter capacitor is a variable capacitor.

8. The circuit capable of realizing electrostatic protection of an antenna end according to any one of claims 1 to 4, further comprising a capacitor and a grounding inductor; the capacitor is connected between the first end of the TVS tube unit and the connecting end of the antenna, and the connecting end of the antenna is grounded through the grounding inductor.

9. An electronic device, comprising the circuit capable of realizing electrostatic protection of an antenna terminal according to any one of claims 1 to 8.

10. The electronic device of claim 9, comprising a metal frame, wherein the antenna is connected to the metal frame.