CN101567789B - Network communication device with electrostatic protection function - Google Patents

Abstract

A network communication device comprises a first pin for transmitting and receiving a first network signal; a second pin for transmitting and receiving a second network signal; and an electrostatic protection circuit, coupled between the first and second pins, for processing a first electrostatic signal inputted from the first pin and a second electrostatic signal inputted from the second pin, wherein the first and second electrostatic signals form a differential signal; when the first and the second electrostatic signals are input, the electrostatic protection circuit is conducted, so that the first pin and the second pin are substantially short-circuited to eliminate the first and the second electrostatic signals.

Description

Network communication device with electrostatic protection function

technical field

The invention relates to a network communication device, in particular to a network communication device with electrostatic discharge protection function.

Background technique

Electrostatic Discharge (ESD) is the main factor that causes most electronic components to be damaged by excessive electrical stress. This damage will cause permanent damage to electronic components, thus affecting the normal operation of electronic components.

In order to solve the problem of electrostatic discharge, the general practice is to use the switching mechanism of the PN junction of the parasitic bicarrier interface transistor (Parasitic BJT) to allow the electrostatic discharge to be derived from the power supply terminal (VDD) or the ground terminal (GND). However, in the application of the Ethernet network, since the cable discharge (Cable Discharge, CDE) occurs on the network cable, and the energy of the cable discharge enters the integrated circuit in a differential form, if the cable discharge passes through the transformer ( Transformer) into the integrated circuit, the static electricity is exported through the power supply terminal or the ground terminal, and a large electrostatic protection circuit needs to be designed to quickly discharge the cable discharge, which will consume a large amount of power. circuit area.

Contents of the invention

Therefore, one of the objectives of the present invention is to provide a network communication device with electrostatic discharge protection function, which can quickly eliminate cable discharge.

The present invention provides a network communication device. The network communication device includes a first pin for transmitting and receiving a first network signal; a second pin for transmitting and receiving a second network signal; The protection circuit is coupled between the first pin and the second pin, and is used for processing a first electrostatic signal input by the first pin and processing a second static signal input by the second pin electrostatic signal, and the first and the second electrostatic signal form a differential signal; wherein, when the first and the second electrostatic signal are input, the electrostatic protection circuit is turned on, so that the first pin and the The second pin substantially forms a short circuit to eliminate the first and the second electrostatic signals.

Description of drawings

FIG. 1 is a schematic diagram of a first embodiment of a network communication device of the present invention.

FIG. 2 is a schematic diagram of a second embodiment of the network communication device of the present invention.

FIG. 3 is a schematic diagram of a third embodiment of a network communication device according to the present invention.

[Description of main component symbols]

100, 200, 300: network communication device

102, 202, 302: the first network signal pin

104, 204, 304: Second network signal pins

106, 206, 306: Electrostatic protection circuit

106a, 106b, 306c, 306d: diodes connected in series

206a, 306a: electrostatic detection circuit

206b, 306b: switch unit

108, 208, 308: Transformer

110, 210, 310: network line

112, 212, 312: Receiver

114, 214, 314: Teleporter

Detailed ways

The following description will illustrate the preferred embodiments of the present invention with reference to the relevant drawings, so that anyone skilled in the art can implement the present invention. Although the embodiments of the present invention are different, the features, structures or characteristics are described herein In order to connect with any implementer, without departing from the scope of the present invention, it can be implemented in other embodiments instead of only the methods described below. In addition, the arrangement and position of individual components in each disclosed embodiment can be modified appropriately without departing from the scope of the present invention, so the protection scope of the present invention should be defined by the appended claims.

First, referring to FIG. 1 , FIG. 1 is a schematic diagram of a first embodiment of a network communication device of the present invention. As shown in the figure, the network communication device 100 includes a first network signal pin 102 for transmitting and receiving a first network signal; The second network signal pin 104 is used to transmit and receive the second network signal; the electrostatic protection circuit 106 is coupled between the first network signal pin 102 and the second network signal pin 104, and the electrostatic protection circuit 106 is used for Process the first static signal and the second static signal received by the first network signal pin 102 and the second network signal pin 104; the static electricity protection circuit 106 includes a first series diode unit 106a and a The second series diode unit 106b; wherein, the anode of one diode in the first series diode unit 106a is coupled to the first network signal pin 102, and the cathode of the other diode is coupled to the second network signal pin 104; The anode of one diode in the second series diode unit 106 b is coupled to the second network signal pin 104 , and the cathode of the other diode is coupled to the first network signal pin 102 .

The operating principle of the first embodiment of the network communication device of the present invention will be described in more detail below. Please refer to the network communication device 100 in FIG. It is not conducted, and the internal transmitter 114 and receiver 112 transmit and receive the first network signal through the first network signal pin 102 and transmit and receive through the second network signal pin 104 The second network signal, wherein, the first network signal and the second network signal are transmitted on the network line in the form of differential signals. According to an embodiment, the above-mentioned network cable can be realized by an RJ45 network cable.

Then, when a cable discharge (Cable Discharge Event, CDE) occurs on the network cable, the generated electrostatic signal will flow into the network communication device 100 through the transformer 108 . As shown in the figure, the first static signal part and the second static signal part of cable discharge flow in from the first network signal pin 102 and the second network signal pin 104 respectively, and the first static signal and the second static signal form a differential signal. When the first electrostatic signal voltage is greater than the second electrostatic signal voltage, the first serially connected diode unit 106a will be turned on, so that the first network signal pin 102 and the second network signal pin 104 substantially form a short circuit, at this time , the first static signal flows through the static protection circuit 106 and is discharged through the second network signal pin 104 . Conversely, when the second electrostatic signal voltage is greater than the first electrostatic signal voltage, the second series diode unit 106b will be turned on, so that the first network signal pin 102 and the second network signal pin 104 are substantially short-circuited, At this moment, the second static electricity signal flows through the static electricity protection circuit 106 and is discharged through the first network signal pin 102 .

Referring to FIG. 2, FIG. 2 is a schematic diagram of a second embodiment of the network communication device of the present invention. As shown in the figure, the network communication device 200 includes a first network signal pin 202 for transmitting and receiving the first network signal; The network signal pin 204 is used to transmit and receive the second network signal; the electrostatic protection circuit 206 is coupled between the first network signal pin 202 and the second network signal pin 204 to process the first network signal pin The first static signal and the second static signal received by the pin 202 and the second network signal pin 204 . The static electricity protection circuit 206 includes a static electricity detection circuit 206a and a switch unit 206b according to the second embodiment, wherein the static electricity detection circuit 206a is used to detect whether there is static electricity in the network line 210; and the switch unit 206b is composed of a PMOS transistor and a switch unit 206b according to an embodiment NMOS transistors are combined in parallel.

As far as the second embodiment is concerned, its operating principle is similar to that of the first embodiment; when the network is operating normally, the electrostatic protection circuit 206 in the network communication device 200 is not turned on, and the internal transmitter 214 and the receiver 212 transmit and receive the first network signal through the first network signal pin 202 and transmit and receive the second network signal through the second network signal pin 204 . When the cable discharge occurs on the network cable, the detection circuit 206a detects that there is an electrostatic signal on the network cable 210, and turns on the switch unit 206b, so that the first network signal pin 202 and the second network signal pin 204 substantially form a short circuit Next, after the path is turned on, the cable discharge generated by the network line passes through the switch unit 206b and is derived through the first network signal pin 202 and the second network signal pin 204 .

Referring to FIG. 3, FIG. 3 is a schematic diagram of a third embodiment of the network communication device of the present invention. As shown in the figure, the network communication device 300 includes a first network signal pin 302 for transmitting and receiving the first network signal; The network signal pin 304 is used to transmit and receive the second network signal; the electrostatic protection circuit 306 is coupled between the first network signal pin 302 and the second network signal pin 304 to process the first network signal pin The pin 302 and the second network signal pin 304 receive the first static signal and the second static signal. The electrostatic protection circuit 306 includes an electrostatic detection circuit 306a, a switch unit 306b, a diode unit 306c, and a diode unit 306d. Wherein, the static electricity detection circuit 306a is used to detect whether there is static electricity on the network line 310; and the switch unit 306b is composed of a PMOS transistor and an NMOS transistor connected in parallel according to an embodiment.

For the third embodiment, its operation principle is similar to that of the first and second embodiments; that is, when the network is operating normally, the electrostatic protection circuit 306 in the network communication device 300 is not turned on, and by The internal transmitter 314 and receiver 312 transmit and receive the first network signal through the first network signal pin 302 and transmit and receive the second network signal through the second network signal pin 304 . Similarly, when the cable discharge occurs on the network cable, the detection circuit 306a detects an electrostatic signal on the network cable 310, and turns on the switch unit 306b, so that the first network signal pin 302 and the second network signal pin 304 are substantially A short circuit is formed; then, the cable discharge of the network line after the path is turned on can be derived from the first network signal pin 302 and the second network signal pin 304 .

In summary, the network communication device of the present invention sets an electrostatic protection circuit between two network signal pins, so that when static electricity occurs, a conduction path is formed between the two network signal pins, and the static electricity It is quickly derived from the network signal pin to prevent electrostatic discharge from destroying the network communication device. In addition, please note that although the electrostatic protection circuit is only described by the above three embodiments, the present invention is not limited thereto, and circuits that can achieve the electrostatic protection function in other equal variations also fall within the scope of the present invention.

Claims (11)

1. network communication device comprises:

One first pin is used for transmitting and reception one first network signal;

One second pin is used for transmitting and reception one second network signal; And

One electrostatic discharge protective circuit, be coupled to this first and this second pin between, be used for handling one first electrostatic signal of importing by this first pin, and handle one second electrostatic signal of importing by this second pin;

Wherein, this first network signal and this second network signal are the forms with differential wave, transmit in that network is online; When this first during with the input of this second electrostatic signal; This electrostatic discharge protective circuit is switched on, and makes this first pin and this second pin form short circuit in fact, with get rid of this first with this second electrostatic signal; This electrostatic discharge protective circuit wherein comprises:

One switch element is coupled between this first pin and this second pin; And

One electrostatic detection circuit is coupled between this first pin and this second pin, is used for detecting this first pin and whether this second pin has electrostatic signal;

Wherein, when this first during with the input of this second electrostatic signal, this this switch element of electrostatic detection circuit turn-on first first is got rid of this with this second pin via this with this second electrostatic signal.

2. network communication device as claimed in claim 1, wherein this electrostatic discharge protective circuit more comprises a diode, is coupled between this switch element and this second pin.

3. according to claim 1 or claim 2 network communication device, wherein this switch is parallelly connected with a PMOS transistor by a nmos pass transistor.

4. network communication device as claimed in claim 1, wherein this first with this second electrostatic signal form a differential wave.

5. network communication device as claimed in claim 1, wherein this first with this second electrostatic signal be a cable discharge signal.

6. network communication device as claimed in claim 1 is applied in the Ethernet.

7. network communication device comprises:

One first pin is used for transmitting and reception one first network signal;

One second pin is used for transmitting and reception one second network signal; And

One electrostatic discharge protective circuit, be coupled to this first and this second pin between, be used for handling an electrostatic signal of importing by this first pin;

Wherein, this first network signal and this second network signal are the forms with differential wave, transmit in that network is online; When this electrostatic signal is imported by first pin; This electrostatic discharge protective circuit is switched on, and makes this electrostatic signal flow through this electrostatic discharge protective circuit and gets rid of via this second pin

This electrostatic discharge protective circuit wherein comprises:

One switch element is coupled between this first pin and this second pin; And

One electrostatic detection circuit is coupled between this first pin and this second pin;

Wherein, when this electrostatic signal was imported by first pin, this this switch element of electrostatic detection circuit turn-on made this electrostatic signal flow through this switch element and gets rid of via this second pin.

8. network communication device as claimed in claim 7, wherein this electrostatic discharge protective circuit more comprises a diode, is coupled between this switch element and this second pin.

9. like claim 7 or 8 described network communication devices, wherein this switch is parallelly connected with a PMOS transistor by a nmos pass transistor.

10. network communication device as claimed in claim 7, wherein this first with this second electrostatic signal be a cable discharge signal.

11. network communication device as claimed in claim 7 is applied in the Ethernet.

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