CN202633896U - Circuit for protecting universal serial bus (USB) interface - Google Patents
Circuit for protecting universal serial bus (USB) interface Download PDFInfo
- Publication number
- CN202633896U CN202633896U CN201220295499XU CN201220295499U CN202633896U CN 202633896 U CN202633896 U CN 202633896U CN 201220295499X U CN201220295499X U CN 201220295499XU CN 201220295499 U CN201220295499 U CN 201220295499U CN 202633896 U CN202633896 U CN 202633896U
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- usb
- voltage comparator
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Abstract
The utility model discloses a circuit for protecting a universal serial bus (USB) interface. The circuit can be used in equipment which uses the USB interface for communication and electricity acquisition, and the USB interface of a computer main board and USB equipment can be effectively protected. The circuit consists of a power switch circuit and an overcurrent testing circuit which are connected with each other. When an internal circuit in the equipment which uses the circuit for protecting the USB interface is in a short circuit condition, the circuit for protecting the USB interface can instantly cut off the power supply of the USB interface, so that the USB interface of the computer main board and the computer main board can be effectively protected; and the circuit is simple and practical, and is convenient to use.
Description
Technical field
the utility model relates to a kind of USB interface protective circuit, and this circuit can be used in and use USB interface to carry out in the equipment of communication or power taking, can effectively protect the USB interface and the USB device of computer main board.
Background technology
are present; Computer generally uses USB interface to carry out communication; Also have more and more equipments to use USB interface and computer to carry out communication or power taking, so if since generally the current capacity of the USB interface of computer all design at 0.5 ampere. the USB device that is designed causes the USB interface overcurrent owing to reasons such as internal short-circuits; Will cause the damage of the USB interface of computer main board, even the damage of mainboard.
Summary of the invention
USB interface and computer main board in order to protect computer main board can be because of the equipment short circuit of using USB interface, and causes damage.The utility model provides a kind of USB interface protective circuit; When having used the device interior short circuit of this USB interface protective circuit; Moment this USB interface protective circuit can cut off the USB interface power supply, thereby can effectively protect the USB interface and the computer main board of computer main board.Circuit is simple, and is convenient and practical.
the utility model solves the technical scheme that its technical problem adopted: this utility model is formed by connecting power switch Dian Lu ﹑ overcurrent test circuit.Power switch circuit is by resistance R 4; PNP triode Q1 forms, and the end of R4 links to each other with the base stage of triode Q1, and the other end of R4 links to each other with the output of voltage comparator U2A; The emitter of triode Q1 meets USB power supply output cathode VCC0, and the collector electrode of triode Q1 meets the VCC of USB device; The overcurrent test circuit is by resistance R 1 ﹑ R2 ﹑ R3, diode D1, and voltage comparator U2A forms; The ground GND of one termination USB device of resistance R 1; Another termination USB power supply output negative pole GND0 of resistance R 1, the anode of diode D1 connects the inverting input of voltage comparator U2A, and the negative electrode of diode D1 meets USB power supply output negative pole GND0; The anode of resistance R 2 one terminating diode D1; Resistance R 2 another termination USB power supply output cathode VCC0, the negative supply of voltage comparator U2A meets GND0, and the positive supply of voltage comparator U2A meets VCC0; The in-phase input end of voltage comparator U2A meets the ground GND of USB device, and the output of voltage comparator U2A connects the base stage of Q1 through resistance R 4, presses the output of comparator U2A to meet VCC0 through resistance R 3 simultaneously; The course of work of the utility model is such: when the USB device internal short-circuit; The electric current that flows through resistance R 1 becomes suddenly big, and the voltage between GND and the GND0 raises, when the electric current that flows through resistance R 1 during greater than 0.5A; The voltage of the in-phase input end of voltage comparator U2A will be greater than inverting input voltage; The output of voltage comparator U2A will become high level, and PNP triode Q1 turn-offs, and has cut off the USB interface power supply.
The beneficial effect of
the utility model is when the USB device internal short-circuit causes overcurrent, can effectively protect the USB interface and the USB device of computer main board, and convenient and practical, cost is low.
Description of drawings
further specify the utility model below in conjunction with accompanying drawing and embodiment.
Fig. 1 is the utility model embodiment circuit theory diagrams.
Embodiment
present embodiment is formed by connecting power switch Dian Lu ﹑ overcurrent test circuit.Power switch circuit is by resistance R 4; PNP triode Q1 forms, and the end of R4 links to each other with the base stage of triode Q1, and the other end of R4 links to each other with the output of voltage comparator U2A; The emitter of triode Q1 meets USB power supply output cathode VCC0, and the collector electrode of triode Q1 meets the VCC of USB device; The overcurrent test circuit is by resistance R 1 ﹑ R2 ﹑ R3, diode D1, and voltage comparator U2A forms; The ground GND of one termination USB device of resistance R 1; Another termination USB power supply output negative pole GND0 of resistance R 1, the anode of diode D1 connects the inverting input of voltage comparator U2A, and the negative electrode of diode D1 meets USB power supply output negative pole GND0; The anode of resistance R 2 one terminating diode D1; Resistance R 2 another termination USB power supply output cathode VCC0, the negative supply of voltage comparator U2A meets GND0, and the positive supply of voltage comparator U2A meets VCC0; The in-phase input end of voltage comparator U2A meets the ground GND of USB device, and the output of voltage comparator U2A connects the base stage of Q1 through resistance R 4, presses the output of comparator U2A to meet VCC0 through resistance R 3 simultaneously; The course of work of the utility model is such: when the USB device internal short-circuit; The electric current that flows through resistance R 1 becomes suddenly big, and the voltage between GND and the GND0 raises, when the electric current that flows through resistance R 1 during greater than 0.5A; The voltage of the in-phase input end of voltage comparator U2A will be greater than inverting input voltage; The output of voltage comparator U2A will become high level, and PNP triode Q1 turn-offs, and has cut off the USB interface power supply.
The principle and the design feature of this utility model can be understood through above accompanying drawing in
.Characteristics such as it is simple to the utlity model has circuit, and cost is low, practical reliable.
Claims (1)
1. USB interface protective circuit; It is characterized in that comprising power switch Dian Lu ﹑ overcurrent test circuit, power switch circuit is by resistance R 4, and PNP triode Q1 forms; The end of R4 links to each other with the base stage of triode Q1; The other end of R4 links to each other with the output of voltage comparator U2A, and the emitter of triode Q1 meets USB power supply output cathode VCC0, and the collector electrode of triode Q1 meets the VCC of USB device; The overcurrent test circuit is by resistance R 1 ﹑ R2 ﹑ R3, diode D1, and voltage comparator U2A forms; The ground GND of one termination USB device of resistance R 1; Another termination USB power supply output negative pole GND0 of resistance R 1, the anode of diode D1 connects the inverting input of voltage comparator U2A, and the negative electrode of diode D1 meets USB power supply output negative pole GND0; The anode of resistance R 2 one terminating diode D1; Resistance R 2 another termination USB power supply output cathode VCC0, the negative supply of voltage comparator U2A meets GND0, and the positive supply of voltage comparator U2A meets VCC0; The in-phase input end of voltage comparator U2A meets the ground GND of USB device, and the output of voltage comparator U2A connects the base stage of Q1 through resistance R 4, presses the output of comparator U2A to meet VCC0 through resistance R 3 simultaneously.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220295499XU CN202633896U (en) | 2012-06-24 | 2012-06-24 | Circuit for protecting universal serial bus (USB) interface |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220295499XU CN202633896U (en) | 2012-06-24 | 2012-06-24 | Circuit for protecting universal serial bus (USB) interface |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202633896U true CN202633896U (en) | 2012-12-26 |
Family
ID=47387042
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201220295499XU Expired - Fee Related CN202633896U (en) | 2012-06-24 | 2012-06-24 | Circuit for protecting universal serial bus (USB) interface |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202633896U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109417283A (en) * | 2016-05-16 | 2019-03-01 | 赛普拉斯半导体公司 | The adjustable over-current detector circuit of universal serial bus (USB) equipment |
| CN113359054A (en) * | 2020-03-04 | 2021-09-07 | 北京小米移动软件有限公司 | Test fixture, power supply test system and test method |
-
2012
- 2012-06-24 CN CN201220295499XU patent/CN202633896U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109417283A (en) * | 2016-05-16 | 2019-03-01 | 赛普拉斯半导体公司 | The adjustable over-current detector circuit of universal serial bus (USB) equipment |
| CN109417283B (en) * | 2016-05-16 | 2020-06-12 | 赛普拉斯半导体公司 | Adjustable overcurrent detector circuit for Universal Serial Bus (USB) device |
| US10847964B2 (en) | 2016-05-16 | 2020-11-24 | Cypress Semiconductor Corporation | Adjustable over-current detector circuit for universal serial bus (USB) devices |
| CN113359054A (en) * | 2020-03-04 | 2021-09-07 | 北京小米移动软件有限公司 | Test fixture, power supply test system and test method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20121226 Termination date: 20130624 |