CN218040774U - USB protection circuit and USB protection device - Google Patents
USB protection circuit and USB protection device Download PDFInfo
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- CN218040774U CN218040774U CN202222026535.9U CN202222026535U CN218040774U CN 218040774 U CN218040774 U CN 218040774U CN 202222026535 U CN202222026535 U CN 202222026535U CN 218040774 U CN218040774 U CN 218040774U
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Abstract
The utility model discloses a USB protection circuit and USB protection device, USB protection circuit include input interface, output interface and short-circuit protection module. The short-circuit protection module is respectively electrically connected with the data end of the input interface and the input end of the output interface, and is used for monitoring and receiving data signals transmitted between the input interface and the output interface and disconnecting the data signal transmission between the input interface and the output interface when the data signals are abnormal. The USB protection circuit monitors the data signals input by the board card by setting the short-circuit protection module, normal data transmission between the board card and the USB flash disk is guaranteed when the board card is normal, and data transmission between the board card and the USB device is timely disconnected when the board card is in a bad short circuit, so that the USB device is protected.
Description
Technical Field
The utility model relates to an electronic circuit technical field especially relates to a USB protection circuit and USB protection device.
Background
When electronic products are produced and manufactured or used daily, the USB equipment is difficult to avoid being damaged due to abnormal voltage of the USB port or even short circuit, and unnecessary loss is brought to production or consumers. For example, in the manufacturing process of the television board card, a poor product of short-circuit connection between a power supply pin and a data pin of the USB port of the board card may occur, and in order to ensure that the USB port can be connected in a normal operation, the USB port needs to be detected for each board card. The current detection mode is to directly plug a detection U disk and the like into a USB port of a board card for detection, and when a plurality of detected defective products exist, the detection U disk is extremely easy to damage. In addition, for example, in the use process of the television, the USB port of the board card is damaged and shorted by multiple plugging and unplugging, and when the USB disk is connected to the board card of the television, the USB disk is directly damaged.
Therefore, when the electronic product is used at present, the damage of the USB equipment caused by the short circuit of the USB port of the board card cannot be completely avoided.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the technical problem that: the utility model provides a USB protection circuit and USB protection device to solve the problem that USB equipment damages because of the USB port short circuit of integrated circuit board leads to.
In order to solve the technical problem, the utility model discloses a technical scheme be:
a USB protection circuit, comprising: the input interface, the output interface and the short-circuit protection module;
the short-circuit protection module is respectively electrically connected with the data end of the input interface and the input end of the output interface, and is used for monitoring and receiving data signals transmitted between the input interface and the output interface and disconnecting the data signal transmission between the input interface and the output interface when the data signals are abnormal.
The overvoltage protection module is respectively connected with the power supply end of the input interface and the power supply end of the output interface, and is used for monitoring and receiving a power supply voltage signal input by the input interface, outputting the power supply voltage signal to the power supply end of the output interface, and disconnecting the power supply voltage signal transmission between the input interface and the output interface when the power supply voltage signal is abnormal.
Further, still include and prevent the surge module, prevent the surge module and connect respectively the data end of input interface and short-circuit protection module, prevent the surge module and be used for releasing static and surge protection.
And the load capacity detection module is connected with the power supply end of the input interface and used for simulating the power supply output load capacity of the board card.
Further, the short-circuit protection module comprises a first sampling unit and a protection chip;
the first sampling unit is respectively electrically connected with the data end of the input interface and the protection chip and is used for acquiring the data signal and sending a first sampling signal to the protection chip according to the data signal;
the protection chip is respectively connected with the data end of the input interface and the data end of the output interface, and the protection chip is used for switching on or switching off data transmission between the data end of the input interface and the data end of the output interface according to the first sampling signal.
Further, the overvoltage protection module comprises a second sampling unit, a photoelectric coupler and a switch unit;
the second sampling unit is connected with the power supply end of the input interface and used for acquiring the power supply voltage signal and sending a second sampling signal to the photoelectric coupler according to the power supply voltage signal;
the photoelectric coupler is connected with the control end of the switch unit and used for sending a control signal to the switch unit according to the second sampling signal;
the input end of the switch unit is connected with the power supply end of the input interface, the output end of the switch unit is connected with the power supply end of the output interface, the power supply voltage signal is transmitted between the input interface and the output interface through the switch unit, and the switch unit is used for switching on or switching off the power supply voltage signal transmission between the input interface and the output interface according to the control signal.
Further, the first sampling unit includes a first resistor, a second resistor, a third resistor and a fourth resistor;
one end of the first resistor is connected with the negative data end of the input interface and is grounded, and the other end of the first resistor is connected with the first pin of the protection chip;
one end of the second resistor is connected with the negative data end of the input interface, and the other end of the second resistor is connected with the first pin of the protection chip;
one end of the third resistor is connected with the complete machine input end of the input interface, and the other end of the third resistor is connected with a third pin of the protection chip;
one end of the fourth resistor is grounded, and the other end of the fourth resistor is connected with a third pin of the protection chip;
the second pin and the fourth pin of the protection chip are grounded, the fifth pin of the protection chip is connected with the positive data end of the output interface, the sixth pin of the protection chip is connected with the positive data end of the input interface, the seventh pin of the protection chip is connected with the negative data end of the output interface, and the eighth pin of the protection chip is connected with the negative data end of the input interface.
Further, the second sampling unit comprises a fifth resistor and a sixth resistor;
one end of the fifth resistor is connected with the power supply end of the input interface, and the other end of the fifth resistor is connected with the first pin of the photoelectric coupler;
one end of the sixth resistor is connected with the first pin of the photoelectric coupler, and the other end of the sixth resistor is grounded;
and a second pin and a fourth pin of the photoelectric coupler are grounded, and a third pin of the photoelectric coupler is connected with the control end of the switch unit.
Further, the switching unit includes a field effect transistor, a gate of the field effect transistor is connected to the third pin of the photoelectric coupler, a source of the field effect transistor is connected to the power supply end of the output interface, and a drain of the field effect transistor is connected to the power supply end of the input interface.
A USB protection device comprises a shell and a circuit board, wherein the circuit board is provided with the USB protection circuit, and the circuit board is installed on the shell.
The beneficial effects of the utility model reside in that: the USB protection circuit monitors the data signals input by the board card by setting the short-circuit protection module, normal data transmission between the board card and the USB flash disk is guaranteed when the board card is normal, and data transmission between the board card and the USB device is timely disconnected when the board card is in a bad short circuit, so that the USB device is protected.
Drawings
Fig. 1 is a first schematic block diagram of a USB protection circuit according to an embodiment of the present invention;
fig. 2 is a second schematic block diagram of a USB protection circuit according to an embodiment of the present invention;
fig. 3 is a third schematic block diagram of a USB protection circuit according to an embodiment of the present invention;
fig. 4 is a fourth schematic block diagram of a USB protection circuit according to an embodiment of the present invention;
fig. 5 is a fifth schematic block diagram of a USB protection circuit according to an embodiment of the present invention;
fig. 6 is a schematic diagram of a USB protection circuit according to an embodiment of the present invention.
Description of the reference symbols:
10. a USB protection circuit; 100. an input interface; 200. an output interface; 300. a short circuit protection module; 310. a first sampling unit; 320. protecting the chip; 400. an overvoltage protection module; 410. a second sampling unit; 420. a photoelectric coupler; 430. a switch unit; 500. an anti-surge module; 600. a load capacity detection module; 700. a board card; 800. a USB device; 900. and a working indicator light.
Detailed Description
In order to explain the technical content, the objects and the effects of the present invention in detail, the following description is made with reference to the accompanying drawings in combination with the embodiments.
Example one
Referring to fig. 1 to 6, a first embodiment of the present invention is:
a USB protection circuit 10 is used for protecting a USB device 800 when the daily USB device 800 is connected to a board card 700 of an electronic product, or protecting the USB device 800 used for detection in the production and detection process of the board card 700. The electronic product may be a television, a desktop computer, a notebook computer, and the like, and the USB device 800 may be a USB disk, a detection USB disk, a mobile hard disk, and the like.
Referring to fig. 1, the USB protection circuit 10 includes: input interface 100, output interface 200 and short-circuit protection module 300. The short-circuit protection module 300 is electrically connected to the data terminal of the input interface 100 and the input terminal of the output interface 200, respectively, and the short-circuit protection module 300 is configured to monitor and receive a data signal transmitted between the input interface 100 and the output interface 200, and disconnect the data signal transmission between the input interface 100 and the output interface 200 when the data signal is abnormal. The input interface 100 and the output interface 200 are both USB interfaces, the input interface 100 is connected to a USB port of the board card 700, the output interface 200 is connected to the USB device 800, and the board card 700 and the USB device 800 transmit data and supply power through the USB protection circuit 10.
The working principle of the USB protection circuit 10 of this embodiment is as follows: the USB end of the board card 700 is connected to the input interface 100, and sends a data signal to the short-circuit protection module 300. The short-circuit protection module 300 obtains the data signal and monitors the state of the data signal, and when the device to be tested and the data signal are normal, the short-circuit protection module 300 sends the data signal to the output interface 200. The USB device 800 is connected to the output interface 200 and receives the data signal, and the USB device 800 may also return data to the board 700 through the short-circuit protection module 300. When the USB port of the board card 700 is short-circuited, the transmitted data signal is abnormal. When the short-circuit protection module 300 detects that the data signal is abnormal, the data transmission between the input interface 100 and the output interface 200 is disconnected. When the data signal is restored to normal, the short-circuit protection module 300 restores the data transmission between the input interface 100 and the output interface 200.
It can be understood that, in this embodiment, the USB protection circuit 10 is disposed between the board card 700 and the USB device 800, and the USB protection circuit 10 is disposed with the short-circuit protection module 300, so that when the board card 700 is in a short circuit failure, the data signal transmission between the board card 700 and the USB device 800 is disconnected in time, thereby protecting the USB device 800.
At present, in the processes of reflow soldering, wave soldering and the like, the board card 700 of the electronic product is inevitably poor in the defects of soldering, missing, port connection soldering and the like of the USB power supply circuit patch, so that the USB power supply voltage is increased, and the USB device 800 such as a USB flash disk and the like is easily burnt out when being connected with the board card 700.
In order to avoid the situation that the USB device 800 is burned out due to the abnormal board card 700 providing an excessively high power supply voltage, please refer to fig. 2, in this embodiment, the USB protection circuit 10 further includes an overvoltage protection module 400. Overvoltage protection module 400 connects respectively input interface 100's supply terminal VCC and output interface 200's supply terminal VCC, overvoltage protection module 400 is used for monitoring, receives the supply voltage signal of input interface 100 input, and will supply voltage signal output extremely output interface 200's supply terminal VCC, and the disconnection when supply voltage signal is unusual input interface 100 with supply voltage signal transmission between the output interface 200.
It can be understood that the board 700 supplies power to the USB device 800 through the overvoltage protection module 400 in the USB protection circuit 10. When the board card 700 and the power supply voltage signal are normal, the overvoltage protection module 400 keeps the power supply voltage transmission between the board card 700 and the USB device 800. When the board card 700 is abnormal and the transmitted power supply voltage is too high, the overvoltage protection module 400 timely disconnects the power supply voltage signal transmitted by the board card 700 to the USB disk or the USB device 800, thereby protecting the USB device 800.
Referring to fig. 4, in detail, the short-circuit protection module 300 includes a first sampling unit 310 and a protection chip 320. The first sampling unit 310 is electrically connected to the data terminal of the input interface 100 and the protection chip 320, respectively, and the first sampling unit 310 is configured to obtain the data signal and send a first sampling signal to the protection chip 320 according to the data signal. The protection chip 320 is respectively connected to the data terminal of the input interface 100 and the data terminal of the output interface 200, and the protection chip 320 is configured to turn on or off data transmission between the data terminal of the input interface 100 and the data terminal of the output interface 200 according to the first sampling signal.
It can be understood that the first sampling unit 310 sends the first sampling signal to the protection chip 320 according to the data signal, and the protection chip 320 monitors the state of the first sampling signal. When the USB port of the board card 700 is short-circuited and the data signal is abnormal, the first sampling unit 310 changes the first sampling signal, and the protection chip 320 disconnects the data signal transmission between the board card 700 and the USB device 800 according to the changed first sampling signal, thereby protecting the USB device 800. When the data signal is recovered to be normal, the first sampling unit 310 recovers the first sampling signal correspondingly, so that the data signal between the board card 700 and the USB device 800 is transmitted normally.
Referring to fig. 6, in detail, the first sampling unit 310 includes a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. One end of the first resistor R1 is connected to the negative data terminal of the input interface 100 and grounded, and the other end of the first resistor R1 is connected to the first pin of the protection chip 320. One end of the second resistor R2 is connected to the negative data terminal of the input interface 100, and the other end of the second resistor R2 is connected to the first pin of the protection chip 320. One end of the third resistor R3 is connected to the complete machine input end of the input interface 100, and the other end of the third resistor R3 is connected to the third pin of the protection chip 320. One end of the fourth resistor R4 is grounded, and the other end of the fourth resistor R4 is connected to the third pin of the protection chip 320. The second pin and the fourth pin of the protection chip 320 are grounded, the fifth pin of the protection chip 320 is connected to the positive data terminal of the output interface 200, the sixth pin of the protection chip 320 is connected to the positive data terminal of the input interface 100, the seventh pin of the protection chip 320 is connected to the negative data terminal of the output interface 200, and the eighth pin of the protection chip 320 is connected to the negative data terminal D of the input interface 100 (please refer to node S2 in fig. 6).
In this embodiment, the first sampling signal includes a first voltage-dividing signal and a second voltage-dividing signal, the data signal transmitted by the negative data terminal D-of the input interface 100 is divided by the first resistor R1 and the second resistor R2 to obtain the first voltage-dividing signal, and the protection chip 320 monitors the first voltage-dividing signal through the first pin. The data signal transmitted by the positive data terminal D + of the input interface 100 is divided by the third resistor R3 and the fourth resistor R4 to obtain a second divided voltage signal, and the protection chip 320 monitors the second divided voltage signal through the third pin.
When the power supply pin of the USB port of the board card 700 is short-circuited with the negative data pin, the negative data terminal D-of the input interface 100 transmits a high-level data signal, and feeds back the first divided signal to the first pin of the protection chip 320 after voltage division by the first resistor R1 and the second resistor R2. At this time, the first pin of the protection chip 320 is at a high level, and the protection chip 320 makes the seventh pin and the eighth pin of itself in a high blocking state, so as to disconnect the data signal transmission between the negative data terminal D-of the input interface 100 and the negative data terminal D-of the output interface 200, thereby protecting the USB device 800. Similarly, when the power supply pin of the USB port of the board card 700 is short-circuited with the positive data pin, the positive data terminal D + of the input interface 100 transmits a high-level data signal, and feeds back the second divided signal to the third pin of the protection chip 320 after voltage division by the third resistor R3 and the fourth resistor R4. At this time, the third pin of the protection chip 320 is at a high level, and the protection chip 320 makes the fifth pin and the sixth pin of itself in a high blocking state, so as to disconnect the data signal transmission between the positive data terminal D + of the input interface 100 and the positive data terminal D + of the output interface 200, thereby protecting the USB device 800. In this embodiment, the protection chip 320 is a chip of an LH1521 model.
Referring to fig. 3, optionally, the USB protection circuit 10 of the present embodiment further includes an anti-surge module 500, the anti-surge module 500 is connected to the data terminal of the input interface 100 and the short-circuit protection module 300 respectively, and the anti-surge module 500 is used for releasing static electricity and performing surge protection.
Referring to fig. 6, in the present embodiment, the anti-surge module 500 includes a first diode D1 and a second diode D2, a positive electrode of the first diode D1 is connected to one end of the first resistor R1, a negative electrode of the first diode D1 is respectively connected to the negative data terminal D-of the input interface 100 and one end of the second resistor R2, a positive electrode of the second diode D2 is grounded, and a negative electrode of the second diode D2 is respectively connected to one end of the second resistor R2 and the negative data terminal D-of the input interface 100.
It can be understood that the USB protection circuit 10 of the present embodiment employs the anti-surge module 500, which can effectively release static electricity and block the impact of the instantaneous surge current at the USB port of the board card 700, thereby protecting the circuit itself and the USB device 800.
Referring to fig. 4 and 6, in particular, the overvoltage protection module 400 includes a second sampling unit 410, a photo coupler 420 and a switching unit 430. The second sampling unit 410 is connected to the power supply terminal VCC of the input interface 100, and the second sampling unit 410 is configured to obtain the power supply voltage signal and send a second sampling signal to the photocoupler 420 according to the power supply voltage signal. The photocoupler 420 is connected to a control end of the switch unit 430, and the photocoupler 420 is configured to send a control signal to the switch unit 430 according to the second sampling signal. The input of switch unit 430 is connected the supply terminal VCC of input interface 100, the output of switch unit 430 is connected the supply terminal VCC of output interface 200, input interface 100 with pass through between the output interface 200 switch unit 430 transmits the supply voltage signal, switch unit 430 is used for the basis control signal switches on or breaks input interface 100 with supply voltage signal transmission between the output interface 200.
As can be appreciated, the second sampling unit 410 sends the second sampling signal to the photo coupler 420 according to the supply voltage signal, and the photo coupler 420 monitors the state of the second sampling signal. When the power supply voltage signal input to the power supply pin of the board card 700 is abnormal, the second sampling unit 410 changes the second sampling signal, and the photocoupler 420 disconnects the transmission of the power supply voltage signal between the board card 700 and the USB device 800 according to the changed second sampling signal, thereby protecting the USB device 800 from being burned out. When the power supply voltage signal is recovered to be normal, the second sampling unit 410 recovers the second sampling signal correspondingly, so that the power supply voltage signal between the board card 700 and the USB device 800 is transmitted normally, thereby supplying power to the USB device 800.
Referring to fig. 6, in detail, the second sampling unit 410 includes a fifth resistor R5 and a sixth resistor R6. One end of the fifth resistor R5 is connected to the power supply terminal VCC of the input interface 100, and the other end of the fifth resistor R5 is connected to the first pin of the photocoupler 420. One end of the sixth resistor R6 is connected to the first pin of the photocoupler 420, and the other end of the sixth resistor R6 is grounded. The second pin and the fourth pin of the photo coupler 420 are grounded, and the third pin of the photo coupler 420 is connected to the control terminal of the switching unit 430. It can be understood that, in this embodiment, the supply voltage signal input by the input interface 100 is divided by the fifth resistor R5 and the sixth resistor R6 to obtain the second sampling signal, and the photocoupler 420 monitors the second sampling signal through the first pin and controls the switch unit 430 according to the second sampling signal. In this embodiment, the photocoupler 420 adopts a chip of type 817C, and the sixth resistor R6 can be a potentiometer, which can adjust the second sampling signal.
Specifically, the switch unit 430 includes a field effect transistor Q1, a gate of the field effect transistor Q1 is connected to the third pin of the photoelectric coupler 420, a source of the field effect transistor Q1 is connected to the power supply terminal VCC of the output interface 200, and a drain of the field effect transistor Q1 is connected to the power supply terminal VCC of the input interface 100 (please refer to a node A1 in fig. 6). It can be understood that, when the supply voltage signal is abnormal, the second sampling signal is changed, and the photocoupler 420 sends a corresponding control signal to the field-effect transistor Q1 according to the changed second sampling signal, so as to turn off the field-effect transistor Q1, and disconnect the transmission of the supply voltage signal between the board card 700 and the USB device 800, thereby protecting the USB device 800. When the power supply voltage signal returns to normal, the second sampling signal also returns to normal, and the photoelectric coupler 420 outputs a corresponding control signal to turn on the field-effect transistor Q1, so as to recover the power supply of the board card 700 to the USB device 800.
Illustratively, the USB protection circuit 10 is applied to a power-on test of the board card 700 to be tested, when the USB port of the board card 700 to be tested is abnormal, the board card 700 to be tested transmits a power supply voltage signal to the detection USB disk through the power supply VCC of the input interface 100 to supply power to the detection USB disk, and meanwhile, the detection USB disk may return data to the board card 700 to be tested through the data terminal of the output interface 200 and the protection chip 320. When the voltage output by the board card 700 is too high, the power supply voltage signal is divided by the fifth resistor R5 and the sixth resistor R6 and then provides a second sampling signal to the photoelectric coupler 420, the photoelectric coupler 420 controls the field-effect tube Q1 to cut off the power supply of the board card 700 to the detection usb disk according to the second sampling signal, and the detection usb disk is prevented from being damaged due to the too high power supply voltage.
Referring to fig. 5 and fig. 6, optionally, the USB protection circuit 10 further includes a loading capability detection module 600, and the loading capability detection module 600 is connected to the power supply terminal VCC of the input interface 100 and is configured to simulate a power supply output loading capability of the board card 700. Specifically, the loading capability detecting module 600 includes a seventh resistor R7, one end of the seventh resistor R7 is connected to the power supply terminal VCC of the input interface 100, and the other end of the seventh resistor R7 is grounded. In this embodiment, the seventh resistor R7 is a power cement resistor, and the resistance of the seventh resistor R7 can be adjusted according to the design requirement of the board card 700.
Optionally, in this embodiment, the USB protection circuit 10 further includes a fuse FU1, a voltage regulator D3, and a working indicator lamp 900, where the fuse FU1 is connected in series between the power supply terminal VCC of the input interface 100 and one end of the fifth resistor R5, so as to protect the circuit itself and the USB device 800 when the input voltage is too high. The positive pole of stabilivolt D3 is connected second pin, fourth pin and the ground connection of optoelectronic coupler 420 respectively, stabilivolt D3's negative pole is connected respectively the drain electrode of field effect transistor Q1 and the power supply VCC of output interface 200 is favorable to guaranteeing field effect transistor Q1's output voltage stability. The positive pole of work pilot lamp 900 is connected the source electrode of field effect transistor Q1, the negative pole ground connection of work pilot lamp 900 is used for USB protection circuit 10 to insert and instruct operating condition behind integrated circuit board 700 and the USB equipment 800.
Example two
The present embodiment provides a USB protection device, which includes a housing and a circuit board, wherein the USB protection circuit 10 is disposed on the circuit board, and the circuit board is mounted on the housing.
To sum up, the utility model provides a USB protection circuit and USB protection device, through setting up short-circuit protection module and overvoltage protection module, data transmission and power supply between monitoring integrated circuit board and the USB equipment can cut off the front and back level of unusual circuit fast effectively when having unusually, avoid damaging USB equipment because of integrated circuit board short circuit or input voltage are too high. Meanwhile, the anti-surge module is arranged, so that damage to the USB equipment caused by instantaneous surge and electrostatic impact of the USB port of the board card can be effectively avoided. In addition, in the production and detection process of the board card, the cost loss of the USB equipment is reduced.
The above mentioned is only the embodiment of the present invention, and not the limitation of the patent scope of the present invention, all the equivalent transformations made by the contents of the specification and the drawings, or the direct or indirect application in the related technical field, are included in the patent protection scope of the present invention.
Claims (10)
1. A USB protection circuit, comprising: the input interface, the output interface and the short-circuit protection module;
the short-circuit protection module is respectively electrically connected with the data end of the input interface and the input end of the output interface, and is used for monitoring and receiving data signals transmitted between the input interface and the output interface and disconnecting the data signal transmission between the input interface and the output interface when the data signals are abnormal.
2. The USB protection circuit according to claim 1, further comprising an overvoltage protection module, where the overvoltage protection module is respectively connected to the power supply terminal of the input interface and the power supply terminal of the output interface, and the overvoltage protection module is configured to monitor and receive a power supply voltage signal input by the input interface, output the power supply voltage signal to the power supply terminal of the output interface, and disconnect transmission of the power supply voltage signal between the input interface and the output interface when the power supply voltage signal is abnormal.
3. The USB protection circuit according to claim 1, further comprising an anti-surge module, wherein the anti-surge module is respectively connected to the data terminal of the input interface and the short-circuit protection module, and the anti-surge module is configured to discharge static electricity and perform surge protection.
4. The USB protection circuit according to claim 1, further comprising a loading capability detection module, wherein the loading capability detection module is connected to the power supply terminal of the input interface, and is configured to simulate a power supply output loading capability of the board card.
5. The USB protection circuit according to claim 1, wherein the short-circuit protection module comprises a first sampling unit and a protection chip;
the first sampling unit is respectively electrically connected with the data end of the input interface and the protection chip and is used for acquiring the data signal and sending a first sampling signal to the protection chip according to the data signal;
the protection chip is respectively connected with the data end of the input interface and the data end of the output interface, and the protection chip is used for switching on or switching off data transmission between the data end of the input interface and the data end of the output interface according to the first sampling signal.
6. The USB protection circuit according to claim 2, wherein the overvoltage protection module comprises a second sampling unit, a photocoupler and a switching unit;
the second sampling unit is connected with the power supply end of the input interface and used for acquiring the power supply voltage signal and sending a second sampling signal to the photoelectric coupler according to the power supply voltage signal;
the photoelectric coupler is connected with the control end of the switch unit and used for sending a control signal to the switch unit according to the second sampling signal;
the input end of the switch unit is connected with the power supply end of the input interface, the output end of the switch unit is connected with the power supply end of the output interface, the power supply voltage signal is transmitted between the input interface and the output interface through the switch unit, and the switch unit is used for switching on or switching off the power supply voltage signal transmission between the input interface and the output interface according to the control signal.
7. The USB protection circuit according to claim 5, wherein the first sampling unit comprises a first resistor, a second resistor, a third resistor and a fourth resistor;
one end of the first resistor is connected with the negative data end of the input interface and is grounded, and the other end of the first resistor is connected with the first pin of the protection chip;
one end of the second resistor is connected with the negative data end of the input interface, and the other end of the second resistor is connected with the first pin of the protection chip;
one end of the third resistor is connected with the complete machine input end of the input interface, and the other end of the third resistor is connected with a third pin of the protection chip;
one end of the fourth resistor is grounded, and the other end of the fourth resistor is connected with a third pin of the protection chip;
the second pin and the fourth pin of the protection chip are grounded, the fifth pin of the protection chip is connected with the positive data end of the output interface, the sixth pin of the protection chip is connected with the positive data end of the input interface, the seventh pin of the protection chip is connected with the negative data end of the output interface, and the eighth pin of the protection chip is connected with the negative data end of the input interface.
8. The USB protection circuit according to claim 6, wherein the second sampling unit comprises a fifth resistor and a sixth resistor;
one end of the fifth resistor is connected with the power supply end of the input interface, and the other end of the fifth resistor is connected with the first pin of the photoelectric coupler;
one end of the sixth resistor is connected with the first pin of the photoelectric coupler, and the other end of the sixth resistor is grounded;
and a second pin and a fourth pin of the photoelectric coupler are grounded, and a third pin of the photoelectric coupler is connected with the control end of the switch unit.
9. The USB protection circuit according to claim 6, wherein the switch unit comprises a field effect transistor, a gate of the field effect transistor is connected to the third pin of the photocoupler, a source of the field effect transistor is connected to the power supply terminal of the output interface, and a drain of the field effect transistor is connected to the power supply terminal of the input interface.
10. A USB protection device comprising a housing and a circuit board on which the USB protection circuit of any one of claims 1 to 9 is disposed, the circuit board being mounted on the housing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222026535.9U CN218040774U (en) | 2022-08-02 | 2022-08-02 | USB protection circuit and USB protection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222026535.9U CN218040774U (en) | 2022-08-02 | 2022-08-02 | USB protection circuit and USB protection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218040774U true CN218040774U (en) | 2022-12-13 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202222026535.9U Active CN218040774U (en) | 2022-08-02 | 2022-08-02 | USB protection circuit and USB protection device |
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| CN (1) | CN218040774U (en) |
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2022
- 2022-08-02 CN CN202222026535.9U patent/CN218040774U/en active Active
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