CN212486118U

CN212486118U - Isolation protection circuit and electronic equipment

Info

Publication number: CN212486118U
Application number: CN202021610825.2U
Authority: CN
Inventors: 郝飞飞
Original assignee: TCL Overseas Electronics Huizhou Ltd
Current assignee: TCL Overseas Electronics Huizhou Ltd
Priority date: 2020-08-05
Filing date: 2020-08-05
Publication date: 2021-02-05
Anticipated expiration: 2030-08-05

Abstract

The utility model discloses an isolation protection circuit and electronic equipment, the circuit includes circuit board, external terminal ground and system ground, the external terminal ground and the system ground are arranged on the circuit board, the external terminal ground and the system ground are isolated from each other; the system ground is connected with the control module of the circuit board, and the external terminal ground is connected with the shell of the external terminal of the circuit board; the external connection terminal ground is connected with the back ground of the circuit board, and the system ground is connected with the back ground of the circuit board. The utility model discloses utilize the mutual isolation of external terminal ground and system ground, can avoid electrostatic current directly to flow into control module and lead to equipment to restart through the system, the antistatic properties of hoisting circuit board reduces the probability that equipment restarted or crashed among the static test process.

Description

Isolation protection circuit and electronic equipment

Technical Field

The utility model relates to a circuit electron field especially relates to isolation protection circuit and electronic equipment.

Background

At present, electronic equipment such as displays, TVs, PCs and the like need to perform electrostatic discharge (ESD) test aiming at a machine core circuit board in the production process. The ground connected with the exposed terminal on the circuit board and the ground connected with the system chip (Soc, CPU, MPU) are generally directly mixed. When the static discharge equipment discharges the external terminal, current can be connected with the external terminal and flows into a system chip in a system, so that the system chip is restarted, crashed or damaged when the instantaneous current is too large.

In addition, in the electrostatic discharge test process, if the external terminal cannot be restored to the state before the restart after the restart of the device due to static electricity, an ESD protection prompt needs to be added at the position of the external terminal, and if the number of the external terminals provided with the ESD protection prompt by the electronic device is too large, the sale of the device and the use of a user will be seriously affected.

SUMMERY OF THE UTILITY MODEL

A primary object of the present invention is to provide an isolation protection circuit and an electronic device, which can solve the problem of easy restart or crash of the device caused by the electrostatic discharge test on the circuit board.

In order to achieve the above object, the present invention provides an isolation protection circuit, including a circuit board, an external terminal ground and a system ground, wherein the external terminal ground and the system ground are disposed on the circuit board, and the external terminal ground and the system ground are isolated from each other;

the system ground is connected with the control module of the circuit board, and the external terminal ground is connected with the shell of the external terminal of the circuit board;

the external connection terminal ground is connected with the back ground of the circuit board, and the system ground is connected with the back ground of the circuit board.

Optionally, the component surface of the circuit board includes a first component surface area and a second component surface area isolated from each other, the external terminal is disposed on the first component surface area of the circuit board, and the external terminal is disposed on the second component surface area of the circuit board systematically.

Optionally, the first element surface area and the second element surface area of the circuit board are respectively provided with a via hole connected to the back surface of the circuit board;

the external terminal ground is connected with the back ground of the circuit board through the via hole in the first element surface area, and the system ground is connected with the back ground of the circuit board through the via hole in the second element surface area.

Optionally, the element surface and the back surface of the circuit board are both provided with printed conductors;

the external terminal is connected with the via hole in the first element surface area through the printed conductor on the first element surface area, and is connected with the via hole in the second element surface area through the printed conductor on the second element surface area systematically.

Optionally, the via includes a parasitic capacitance and a parasitic inductance.

Optionally, the circuit board is fixed to a backplane of the electronic device through a backplane fixing member, and the backplane of the electronic device is grounded or the backplane is a floating air-cooled ground of the electronic device;

the back surface of the circuit board is connected with the back plate of the electronic equipment through the back plate fixing piece.

Optionally, the external terminal ground is further configured to receive an electrostatic current discharged by an ESD test device, so as to perform an electrostatic discharge test through the ESD test device.

Furthermore, to achieve the above object, the present invention also provides an electronic device, which includes a back plate and an isolation protection circuit disposed on the back plate and connected to ground through the back plate, wherein the isolation protection circuit is configured as the above isolation protection circuit.

The utility model discloses a carry out mutual isolation to external terminal ground and system ground, can avoid electrostatic current directly to flow into control module and lead to equipment to restart or crash through the system. And the external terminal ground and the system ground are respectively and independently connected with the back surface of the circuit board, so that the normal grounding function can be realized. Static current is at the in-process that flows into control module through external terminal ground, back ground, system, and the impact nature of electric current will reduce greatly to promote the antistatic properties of circuit board, reduce the probability that equipment restarts or crashes among the static test process.

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 the structures shown in the drawings without creative efforts.

Fig. 1 is a schematic circuit diagram of an embodiment of the isolation protection circuit of the present invention.

The objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				10	Circuit board	50	ESD test equipment
20	Via hole	TGND	External terminal ground
				30	Back plate	SGND	Ground of system
31	Back board fixing piece	BGND	Back floor
				40	Control module

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

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 efforts belong to the protection scope of the present invention.

It should be noted that all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit ly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

The utility model provides an isolation protection circuit is applied to electronic equipment, and this electronic equipment can be display, PC, TV etc.. The isolation protection circuit can protect a control module on a circuit board in the process of carrying out electrostatic discharge test on the circuit board, and avoids equipment from being restarted or halted due to electrostatic test.

Referring to fig. 1, in an embodiment, the isolation protection circuit includes a circuit board 10, an external Terminal ground TGND (Terminal ground) and a System ground SGND (System ground), wherein the external Terminal ground TGND and the System ground SGND are both disposed on the circuit board 10, and the external Terminal ground TGND and the System ground SGND are isolated from each other. The system ground SGND is disposed on the front surface, i.e., the component surface, of the circuit board 10, and may be connected to the ground terminal of the control module 40 of the circuit board 10. The external terminal ground TGND is also disposed on the front surface of the circuit board 10 and is connected to a housing of the external terminal on the circuit board 10, which may be a conductive metal housing.

The external terminal ground TGND is also connected to a Back ground BGND (Back ground) of the circuit board 10, and when receiving the electrostatic current flowing through the case, the external terminal ground TGND can be connected to a cold ground through the Back ground BGND of the circuit board 10. The system ground SGND is also connected to the rear ground BGND of the circuit board 10, and the control module 40 can be switched into the cold ground via the system ground SGND and the rear ground BGND. Wherein, the cold ground can be connected with the ground, and the voltage difference relative to the ground is 0; the cold ground may be a floating air-cooled ground, which is not connected to the ground and has a certain voltage difference with respect to the ground.

It is understood that the external terminal ground TGND and the system ground SGND are isolated from each other, that is, the control module 40 is not located on the direct discharge path of the static electricity current, and even though the static electricity flows into the external terminal ground TGND through the external terminal housing, the static electricity cannot directly flow into the system ground SGND, but needs to flow into the back surface ground BGND of the circuit board 10 through the external terminal ground TGND and then flow into the system ground SGND from the back surface ground BGND. The impact of the static current on the control module 40 can be greatly reduced in the process of the static current flowing into the system ground SGND, so that the phenomenon that the static current flows into the control module 40 to cause equipment restart or crash is avoided.

In the present embodiment, by isolating the external terminal ground TGND and the system ground SGND from each other, it is possible to prevent an electrostatic current from flowing into the control module 40 directly through the system ground SGND, resulting in a restart or a crash of the device. And the external terminal ground TGND and the system ground SGND are each separately connected to the back ground BGND of the circuit board 10, so that a normal grounding function can be realized. Static current is at the in-process that flows into control module 40 through external terminal ground TGND, back ground BGND, system ground SGND, and the impact nature of electric current will reduce greatly to promote the antistatic properties of circuit board 10, reduce the probability that equipment restarts or crashes among the static test process, can also reduce the external terminal quantity that sets up the ESD protection suggestion.

Further, the component surface of the circuit board 10 may be divided into two areas separated from each other, i.e., a first component surface area and a second component surface area. The external terminal ground TGND and the system ground SGND on the circuit board 10 may be plural. All the external terminal grounds TGND are disposed in the first element surface region, all the system grounds SGND are disposed in the second element surface region, and any one of the external terminal grounds TGND and any one of the system grounds SGND are not connected by a printed wiring, i.e., all the external terminal grounds TGND are isolated from all the system grounds SGND.

It is understood that the conductor tracks on the printed circuit board 10 that are involved in signal transmission do not enter the first component surface region, i.e. the signal transmission does not pass through the external connection ground TGND. The wiring method may be Layout of Layout.

Through holes 20 connected with the back surface BGND of the circuit board 10 are respectively arranged in the first element surface area and the second element surface area, the through holes 20 can be metalized holes, and when the circuit board 10 has double surfaces or the circuit board 10 is a multilayer board, the through holes 20 can be communicated with printed leads of each layer of the circuit board 10. In this embodiment, the vias 20 may connect the traces on the component side to the traces on the backside, and the traces on the backside of the circuit board 10 may connect to the ground BGND on the backside. The external terminal ground TGND may be connected to the back ground BGND of the circuit board 10 through the via 20 in the first element surface region, and the system ground SGND may be connected to the back ground BGND of the circuit board 10 through the via 20 in the second element surface region.

The number of the vias 20 in the first element surface area may be one or more, and all the external terminal grounds TGND in the first element surface area may be connected to the vias 20 in the first element surface area through the printed wires arranged in the first element surface area. The number of vias 20 in the second element region may be one or more, and all of the system ground SGNDs in the second element region may be connected to the vias 20 in the second element region through a printed wiring provided in the second element region. That is, after passing through the external terminal housing, the electrostatic current flows into the control module 40 of the circuit board 10 through the external terminal ground TGND, the printed wiring, the via hole 20 in the first element surface area, the back ground BGND, the via hole 20 in the second element surface area, the printed wiring, and the system ground SGND in sequence, thereby preventing the device from being restarted or halted due to the electrostatic reaching the control module 40.

It should be noted that, the via hole 20 for connecting the element surface and the back surface of the circuit board 10 has a parasitic capacitance and a parasitic inductance relative to the ground, the parasitic capacitance can play a role in slowing down the increase of the current when the electrostatic current flows, and the parasitic inductance can suppress the change of the current and can also play a role in slowing down the increase of the current. The surge of the electrostatic current can be reduced by the parasitic capacitance and the parasitic inductance. It can be understood that the static current at least needs to flow through two or more vias 20 during the process of flowing through the external terminal ground TGND, the back ground BGND and the system ground SGND, so that the current increase speed is further delayed, and the static current finally reaching the control module 40 can no longer cause the control module 40 to restart or crash, thereby improving the anti-static performance of the circuit board 10.

Further, the circuit board 10 may be fixed on the back plate 30 of the electronic device by a back plate fixing member 31, wherein the back plate fixing member 31 has a conductive property, and may be a back plate stud, the back plate 30 of the electronic device may be a metal back plate 30, and the back plate 30 may be connected to the ground, or the back plate 30 is a floating air-cooled ground of the electronic device and is not connected to the ground. The back surface ground BGND of the circuit board 10 may be connected to the back plate 30 of the electronic device through the conductive back plate holder 31, and when the ESD test device 50 discharges the external terminal, the electrostatic current may flow into the ground through the external terminal ground TGND, the back surface ground BGND, the back plate holder 31, and the back plate 30 of the electronic device. In the ESD test device 50, different electrostatic voltage levels, such as ± 5KV, may be tested during the electrostatic discharge test, and the test mode may be contact discharge or air discharge. The ESD test device 50 may be an electrostatic discharge tester, and during the contact discharge process, the electrostatic discharge tester may discharge the exposed metal terminal of the electronic device through the tip head; in the air discharging process, the electrostatic discharge tester can discharge the gap part of the electronic equipment through the round gun head (such as the periphery of the shell, the USB interface, MIC, REC, SPEAKE, the periphery of an LCD and keys). It will be appreciated that the external terminal housing on the circuit board 10 is capable of receiving a corresponding electrostatic current when discharging the electronic device.

The utility model also provides an electronic equipment, this electronic equipment include backplate 30 and set up in on the backplate 30 and pass through the isolation protection circuit of backplate 30 ground connection, above-mentioned embodiment can be referred to this isolation protection circuit's structure, no longer gives unnecessary details here. It should be understood that, because the electronic device of this embodiment adopts the technical solution of the isolation protection circuit, the electronic device has all the beneficial effects of the isolation protection circuit.

The above is only the optional embodiment of the present invention, and not therefore the scope of the present invention is limited, all the equivalent structures or equivalent flow changes made by the contents of the specification and the drawings, or directly or indirectly applied to other related technical fields, are included in the same way in the protection scope of the present invention.

Claims

1. An isolation protection circuit is characterized by comprising a circuit board, an external terminal ground and a system ground, wherein the external terminal ground and the system ground are arranged on the circuit board, and the external terminal ground and the system ground are isolated from each other;

2. The isolation protection circuit of claim 1, wherein the component side of the circuit board includes a first component side region and a second component side region isolated from each other, the external terminals are systematically disposed in the first component side region of the circuit board, and the external terminals are systematically disposed in the second component side region of the circuit board.

3. The isolation protection circuit of claim 2, wherein the first component face area and the second component face area of the circuit board are respectively provided with vias connected to a back ground of the circuit board;

4. The isolation protection circuit of claim 3, wherein the circuit board is provided with printed conductors on both the component side and the back side;

5. The isolation protection circuit of claim 4, wherein the via comprises a parasitic capacitance and a parasitic inductance.

6. The isolation protection circuit of claim 3, wherein the circuit board is fixed to a backplane of an electronic device by a backplane fixture, the backplane of the electronic device is grounded or the backplane is a floating air ground of the electronic device;

7. The isolation protection circuit of any one of claims 1 to 6, wherein the external terminal ground is further used for receiving an electrostatic current discharged by an ESD test device so as to perform an electrostatic discharge test through the ESD test device.

8. An electronic device, comprising a backplane and an isolation protection circuit disposed on the backplane and grounded via the backplane, wherein the isolation protection circuit is configured as the isolation protection circuit of any one of claims 1 to 7.