1. Technical Field
The present disclosure relates to an electronic device and an anti-static protection circuit employed in the electronic device.
2. Description of Related Art
When an electronic device is connected to an external device via its port, external static electricity may flow into the circuit board of the electronic device via the port, and possibly damage electronic components mounted on the circuit board. Protection components are often added between the port and the other electronic components of the electronic device, to discharge static electricity. However, the added external protection components will increase the manufacturing cost of the electronic device, and make the structure of the electronic device complex.
Therefore, what is needed is an electronic device and an anti-static protection circuit to overcome the problems mentioned above.
Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Referring to
Referring to
The protection circuit 30 includes a first discharge unit 31, a second discharge unit 32, and a capacitor 33. The first discharge unit 31 is electrically connected between the second pin 12 of the port 10 and one terminal of the capacitor 33, and the second discharge unit 32 is electrically connected between the first pin 11 and the other terminal of the capacitor 33. The first discharge unit 31 has an electric wire 311 arranged in a zigzag fashion, the zigzag electric wire 311 includes a number of first sharp turning points 312 opposing to the second discharge unit 32, and the second discharge unit 32 also has an electric wire 321 arranged in a zigzag fashion, the zigzag electric wire 321 includes a number of second sharp turning points 322 spaced apart from and directly opposing to the corresponding first sharp turning points 312 of the first discharge unit 31.
In use, if external static electricity flows into the electronic device 100 from the second pin 12 of the port 10, the first sharp turning points 312 will absorb static electricity flowing to the first discharge unit 31 and discharge part of the static electricity to the air; and the second sharp turning points 322 of the second discharge unit 32 will absorb part of the static electricity on the first sharp turning points 312 and discharge the part of the static electricity to the ground through the grounded first pin 11; and the remaining static electricity flowing to the capacitor 33 through the first discharge unit 31 and the second discharge unit 32 will be absorbed by the capacitor 33. Thereby, static electricity flowing into the electronic device 100 from the port 10 is reduced or even eliminated, and the electronic components of the electronic device 100 are protected.
In the embodiment, when external static electricity flows to the first discharge unit 31, the first sharp turning points 312 acts to discharge and generates a breakdown current, and the breakdown current is transmitted to ground to be discharged through the second sharp turning points 322.
Referring also to
A transmission line 42 is connected between the first discharge unit 31 and the capacitor 33. In the embodiment, the transmission line 42 is bent, such as being bent to an āLā shape to block the flowing of the static electricity, so as to reduce the amount of the static electricity flowing into the capacitor 33.
A transmission line 43 is connected between the second pin 12 and the first discharge unit 31. In the embodiment, the width of the transmission line 43 is gradedly reduced from the second pin 12 to the first discharge unit 31, to quicken the flow of the static electricity 50 to the first sharp turning points 312 of the first discharge unit 31.
The capacitor 33 absorbs the remaining static electricity which is not discharged by the first discharge unit 31 and the second discharge unit 32. In the embodiment, the capacitor 33 is a non-polar patch capacitor.
Moreover, it is to be understood that the disclosure may be embodied in other forms without departing from the spirit thereof. Thus, the present examples and embodiments are to be considered in all respects as illustrative and not restrictive, and the disclosure is not to be limited to the details given herein.
Number | Date | Country | Kind |
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201210097101.6 | Apr 2012 | CN | national |