CN111782564A - USB interface circuit and electronic device using same - Google Patents
USB interface circuit and electronic device using same Download PDFInfo
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- CN111782564A CN111782564A CN201910273113.1A CN201910273113A CN111782564A CN 111782564 A CN111782564 A CN 111782564A CN 201910273113 A CN201910273113 A CN 201910273113A CN 111782564 A CN111782564 A CN 111782564A
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- 238000004891 communication Methods 0.000 claims abstract description 8
- 238000001914 filtration Methods 0.000 claims abstract description 3
- 239000003990 capacitor Substances 0.000 claims description 48
- 230000008054 signal transmission Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 2
- 230000011664 signaling Effects 0.000 description 2
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F13/00—Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units
- G06F13/38—Information transfer, e.g. on bus
- G06F13/382—Information transfer, e.g. on bus using universal interface adapter
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F13/00—Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units
- G06F13/38—Information transfer, e.g. on bus
- G06F13/42—Bus transfer protocol, e.g. handshake; Synchronisation
- G06F13/4282—Bus transfer protocol, e.g. handshake; Synchronisation on a serial bus, e.g. I2C bus, SPI bus
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Abstract
The invention provides an electronic device which comprises a USB interface circuit and a main control chip. The USB interface circuit is connected with the main control chip and is used for realizing communication connection between the main control chip and the USB equipment. The USB interface circuit also comprises a USB interface, a switching driver and a filter circuit. The USB interface is used for being plugged with the USB equipment to establish electrical connection. The adapter driver is electrically connected between the USB interface and the main control chip and drives signals transmitted between the USB equipment and the main control chip according to a preset coefficient. The filter circuit is electrically connected between the USB interface and the adapter driver and is used for filtering common-mode interference between the USB interface and the adapter driver. Therefore, the plugged USB equipment can be effectively identified.
Description
Technical Field
The invention relates to a USB interface circuit and an electronic device applying the same.
Background
With the rapid development of Universal Serial Bus (USB) technology, USB interfaces can be classified into types of Type-A, Type-B, Type-C, etc. according to the types of the interfaces. The USB interface can be divided into USB 1.0, USB2.0, USB3.0, etc. according to different transmission rates. The existing USB3.0 circuit has design defects, and when compatibility test is carried out on a USB3.0 interface, partial plugged USB equipment cannot be identified.
Disclosure of Invention
Accordingly, there is a need for a USB interface circuit for effectively identifying USB devices and an electronic apparatus using the USB interface circuit.
A USB interface circuit for realizing communication connection between a USB device and a main control chip, the USB interface circuit comprising:
the USB interface is used for being plugged with the USB equipment to establish electrical connection;
the adapter driver is electrically connected between the USB interface and the main control chip and drives signals transmitted between the USB equipment and the main control chip according to a preset coefficient; and
the filter circuit is electrically connected between the USB interface and the adapter driver and is used for filtering common-mode interference between the USB interface and the adapter driver.
Further, the USB interface is a Type-A interface.
Furthermore, the filter circuit includes a first capacitor, a second capacitor, a first resistor and a second resistor, the first capacitor is connected between the first signal receiving pin of the adaptor driver and the first signal sending pin of the USB interface, the second capacitor is connected between the second signal receiving pin of the adaptor driver and the second signal sending pin of the USB interface, one end of the first resistor is connected to a first node between the first capacitor and the first signal sending pin, the other end of the first resistor is grounded, one end of the second resistor is connected to a second node between the second capacitor and the second signal sending pin, and the other end of the second resistor is grounded.
Further, the capacitance values of the first capacitor and the second capacitor are both 330nF, and the resistance values of the first resistor and the second resistor are 220 kohm.
Further, the USB interface is a Type-C interface.
Further, the USB interface circuit further includes a multiplexer electrically connected between the USB interface and the adaptor driver.
Further, the filter circuit includes a third capacitor, a fourth capacitor, a third resistor, and a fourth resistor, the third capacitor is connected between the first signal receiving pin of the adaptor driver and the first signal sending pin of the multiplexer, the fourth capacitor is connected between the second signal receiving pin of the adaptor driver and the second signal sending pin of the multiplexer, one end of the third resistor is connected to a third node between the third capacitor and the first signal pin of the multiplexer, the other end of the third resistor is grounded, one end of the fourth resistor is connected to a fourth node between the fourth capacitor and the second signal receiving pin of the adaptor driver, and the other end of the fourth resistor is grounded.
Further, the capacitance values of the third capacitor and the fourth capacitor are both 330nF, and the resistance values of the third resistor and the fourth resistor are 220 kohm.
An electronic device comprises a main control chip and the USB interface circuit, wherein the USB interface circuit is connected with the main control chip.
Further, the main control chip is a south bridge chip.
The filter circuit is arranged between the USB interface and the adapter driver, so that common mode interference between the USB interface and the adapter driver is eliminated. As such, the USB device will be effectively identified.
Drawings
Fig. 1 is a block diagram of a first embodiment of an electronic device according to the present invention.
FIG. 2 is a partial circuit diagram of a preferred embodiment of the USB interface circuit of FIG. 1.
Fig. 3 is a block diagram of a second embodiment of the electronic device of the present invention.
FIG. 4 is a partial circuit diagram of a preferred embodiment of the USB interface circuit of FIG. 3.
Description of the main elements
Nodes P0, P1, P2, P3, P4
Capacitors C1, C2
Resistors R1 and R2
The following detailed description will further illustrate the invention in conjunction with the above-described figures.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the USB interface circuit and the electronic device using the USB interface circuit of the present invention will be described in detail with reference to the accompanying drawings and embodiments.
Referring to fig. 1, a preferred embodiment of the present invention provides an electronic device 100, wherein the electronic device 100 includes a USB interface circuit 10 and a main control chip 20. The USB interface circuit 10 is in communication connection with the main control chip 20, the USB interface circuit 10 is used for implementing communication connection between the main control chip 20 and the USB device 200, and signals between the electronic apparatus 100 and the USB device 200 are transmitted in two directions.
In this embodiment, the electronic device 100 is preferably a master device, and the USB device 200 is preferably a slave device, such as a USB disk, a USB interface mouse, a USB interface camera, and the like. The main control chip 20 is preferably a south bridge chip (PCH) of a notebook computer.
The USB interface circuit 10 includes a USB interface 12, a redriver 14, and a filter circuit 16. The USB interface 12 is used for electrically connecting with an interface (not shown) of the USB device 200. In this embodiment, the USB interface 12 is a Type-a interface. The adaptor driver 14 is electrically connected between the USB interface 12 and the main control chip 20. The filter circuit 16 is electrically connected to a node P0 between the USB interface 12 and the adaptor driver 14.
The through driver 14 is configured to amplify the signal transmitted between the USB device 200 and the main control chip 20 according to a preset coefficient a1, that is, to re-drive the transmission signal, so as to avoid attenuation of the signal due to an excessively long line in the transmission process.
For example, the USB apparatus 200 sends a first signal to the adaptor driver 14 of the electronic device 100 through the USB interface 12, the first signal is transmitted through a cable, the first signal is attenuated by a certain coefficient during transmission, after receiving the first signal, the adaptor driver 14 amplifies the first signal according to a preset coefficient a1, that is, re-drives the first signal, the re-driven signal is named as a second signal, and transmits the second signal to the main control chip 20, wherein the preset coefficient a1 is set such that the signal strength of the second signal is the same as the signal strength of the first signal. In this way, the communication connection between the main control chip 20 and the USB device 200 will be realized.
The USB interface 12 transmits signals to the adaptor driver 14 through a pair of differential signal lines, so that common mode interference occurs during the transmission of signals from the USB interface 12 to the adaptor driver 14, which may result in that the electronic apparatus 100 cannot identify the plugged USB device 200.
In this embodiment, the filter circuit 16 is configured to filter out a common mode interference between the USB interface 12 and the adaptor driver 14. In this way, the electronic apparatus 100 can identify the plugged USB device 200.
Referring to FIG. 2, the filter circuit 16 includes two capacitors C1-C2 and two resistors R1-R2. The USB interface 12 includes a pair of signal transmission pins TX _ DP and TX _ DN, and the redriver 14 includes a pair of signal reception pins RXA _ DP and RXA _ DN. The signal receiving pins RXA _ DP and RXA _ DN of the through driver 14 are electrically connected to the signal transmitting pins TX _ DP and TX _ DN of the USB interface 12, respectively, for receiving signals transmitted by the USB interface 12.
In this embodiment, the capacitor C1 is connected between the signal transmitting pin TX _ DP and the signal receiving pin RXA _ DP. One end of the resistor R1 is connected to the node P1 between the capacitor C1 and the signal transmission pin TX _ DP, and the other end of the resistor R1 is grounded. The capacitor C2 is connected between the signal transmission pin TX _ DN and the signal reception pin RXA _ DN. One end of the resistor R2 is connected to a node P2 between the capacitor C2 and the signal transmission pin TX _ DN, and the other end of the resistor R2 is grounded.
The capacitor C1 and the resistor R1 form a first RC filter unit, and the capacitor C2 and the resistor R2 form a second RC filter unit. The first RC filter unit and the second RC filter unit can effectively filter the common mode interference between the USB interface 12 and the adaptor driver 14, so that the electronic device 100 can effectively identify the USB apparatus 200.
In one embodiment, the capacitance values of the capacitor C1 and the capacitor C2 are preferably 330nF, and the resistance values of the resistor R1 and the resistor R2 are preferably 220 kohm.
Referring to fig. 3, fig. 3 is a block diagram of a second embodiment of the present invention, which is different from the first embodiment in that: the USB interface circuit 10 also includes a multiplexer 18. The multiplexer 18 is electrically connected between the USB interface 12 and the node P0. In this embodiment, the USB interface 12 is a Type-C interface.
Referring to fig. 4, the USB interface 12 includes signal receiving pins RX1_ DP, RX1_ DN, RX2_ DP, and RX2_ DN. The USB interface 12 also includes signaling pins TX1_ DP, TX1_ DN, TX2_ DP, and TX2_ DN. The multiplexer 18 includes signal receiving pins DB _ a1, DB _ b1, DB _ a2, and DB _ b2. The multiplexer 18 also includes signaling pins DB _ a and DB _ b. The signal transmitting pins DB _ a and DB _ b of the multiplexer 18 are communicatively connected to the signal receiving pins RXA _ DP and RXA _ DN of the through driver 14, respectively.
When the USB apparatus 200 is plugged into the USB interface 12 in a first plugging manner, that is, the USB apparatus 200 is electrically connected to the signal receiving pins RX1_ DP and RX1_ DN of the USB interface 12, the signal receiving pins DB _ a1 and DB _ b1 of the multiplexer 18 are respectively connected to the signal sending pins TX1_ DP and TX1_ DN of the USB interface 12 in a communication manner.
When the USB apparatus 200 is plugged into the USB interface 12 in a second plugging manner, that is, the USB apparatus 200 is electrically connected to the signal receiving pins RX2_ DP and RX2_ DN of the USB interface 12, the signal receiving pins DB _ a2 and DB _ b2 of the multiplexer 18 are respectively connected to the signal sending pins TX2_ DP and TX2_ DN of the USB interface 12 in a communication manner. In this way, the USB apparatus 200 is plugged into the USB interface 12 by the first plugging method or the second plugging method, and the USB apparatus 200 can transmit signals to the adaptor driver 14 through the USB interface 12 and the multiplexer 18.
In this embodiment, the capacitor C1 is connected between the signal receiving pin RXA _ DP and the signal transmitting pin DB _ a. One end of the resistor R1 is connected to the node P3 between the capacitor C1 and the signal transmission pin DB _ a, and the other end of the resistor R1 is grounded. The capacitor C2 is connected between the signal receiving pin RXA _ DN and the signal transmitting pin DB _ b. One end of the resistor R2 is connected to the node P4 between the capacitor C2 and the signal transmission pin DB _ b, and the other end of the resistor R2 is grounded.
The capacitor C1 and the resistor R1 form a first RC filter unit, and the capacitor C2 and the resistor R2 form a second RC filter unit. The first RC filter unit and the second RC filter unit can effectively filter the common mode interference between the USB interface 12 and the adaptor driver 14, so that the electronic device 100 can effectively identify the USB apparatus 200.
The USB interface circuit 10 and the electronic device 100 using the USB interface circuit 10 are configured with the filter circuit 16 between the USB interface 12 and the adaptor driver 14 to filter the common mode interference between the USB interface 12 and the adaptor driver 14. In this way, the electronic apparatus 100 can effectively identify the USB device 200.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and are not limited, although the present invention is described in detail with reference to the preferred embodiments.
It will be understood by those skilled in the art that various modifications and equivalent arrangements can be made without departing from the spirit and scope of the present invention.
Moreover, based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without any creative effort will fall within the protection scope of the present invention.
Claims (10)
1. A kind of USB interface circuit, is used for realizing the communication connection between USB apparatus and main control chip, characterized by that, the said USB interface circuit includes:
the USB interface is used for being plugged with the USB equipment to establish electrical connection;
the adapter driver is electrically connected between the USB interface and the main control chip and drives signals transmitted between the USB equipment and the main control chip according to a preset coefficient; and
the filter circuit is electrically connected between the USB interface and the adapter driver and is used for filtering common-mode interference between the USB interface and the adapter driver.
2. The USB interface circuit of claim 1, wherein the USB interface is a Type-a interface.
3. The USB interface circuit of claim 2, wherein the filter circuit comprises a first capacitor, a second capacitor, a first resistor, and a second resistor, the first capacitor is connected between the first signal receiving pin of the through-driver and the first signal transmitting pin of the USB interface, the second capacitor is connected between the second signal receiving pin of the through-driver and the second signal transmitting pin of the USB interface, one end of the first resistor is connected to a first node between the first capacitor and the first signal transmitting pin, the other end of the first resistor is grounded, one end of the second resistor is connected to a second node between the second capacitor and the second signal transmitting pin, and the other end of the second resistor is grounded.
4. The USB interface circuit according to claim 3, wherein the capacitance values of the first capacitor and the second capacitor are both 330nF, and the resistance values of the first resistor and the second resistor are 220 kOhm.
5. The USB interface circuit of claim 1, wherein the USB interface is a Type-C interface.
6. The USB interface circuit of claim 5, further comprising a multiplexer electrically connected between the USB interface and the redriver.
7. The USB interface circuit of claim 6, wherein the filter circuit comprises a third capacitor, a fourth capacitor, a third resistor, and a fourth resistor, the third capacitor is connected between the first signal receiving pin of the adaptor driver and the first signal sending pin of the multiplexer, the fourth capacitor is connected between the second signal receiving pin of the adaptor driver and the second signal sending pin of the multiplexer, one end of the third resistor is connected to a third node between the third capacitor and the first signal pin of the multiplexer, the other end of the third resistor is grounded, one end of the fourth resistor is connected to a fourth node between the fourth capacitor and the second signal receiving pin of the adaptor driver, and the other end of the fourth resistor is grounded.
8. The USB interface circuit according to claim 7, wherein the capacitance values of the third capacitor and the fourth capacitor are both 330nF, and the resistance values of the third resistor and the fourth resistor are 220 kOhm.
9. An electronic device comprising a main control chip and the USB interface circuit according to any one of claims 1-8, wherein the USB interface circuit is connected to the main control chip.
10. The electronic device of claim 9, wherein the main control chip is a south bridge chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910273113.1A CN111782564A (en) | 2019-04-04 | 2019-04-04 | USB interface circuit and electronic device using same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910273113.1A CN111782564A (en) | 2019-04-04 | 2019-04-04 | USB interface circuit and electronic device using same |
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| Publication Number | Publication Date |
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| CN111782564A true CN111782564A (en) | 2020-10-16 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201910273113.1A Pending CN111782564A (en) | 2019-04-04 | 2019-04-04 | USB interface circuit and electronic device using same |
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| CN (1) | CN111782564A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114579492A (en) * | 2022-02-18 | 2022-06-03 | 长沙朗源电子科技有限公司 | Port signal switching control circuit |
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| CN103257944A (en) * | 2013-04-24 | 2013-08-21 | 江苏沁恒股份有限公司 | Method and device for long-distance transmission of USB signals |
| CN103312281A (en) * | 2012-03-16 | 2013-09-18 | 鸿富锦精密工业(武汉)有限公司 | USB (Universal Serial Bus) signal amplification circuit |
| CN103312280A (en) * | 2012-03-16 | 2013-09-18 | 鸿富锦精密工业(武汉)有限公司 | USB (Universal Serial Bus) signal amplification circuit |
| CN103941811A (en) * | 2013-01-23 | 2014-07-23 | 鸿富锦精密工业（深圳）有限公司 | Notebook computer |
| CN104135148A (en) * | 2014-07-17 | 2014-11-05 | 青岛歌尔声学科技有限公司 | USB (Universal Serial Bus) interface circuit |
| CN106610907A (en) * | 2015-10-26 | 2017-05-03 | 鸿富锦精密工业(武汉)有限公司 | Signal conversion circuit and communication system applying same |
-
2019
- 2019-04-04 CN CN201910273113.1A patent/CN111782564A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103312281A (en) * | 2012-03-16 | 2013-09-18 | 鸿富锦精密工业(武汉)有限公司 | USB (Universal Serial Bus) signal amplification circuit |
| CN103312280A (en) * | 2012-03-16 | 2013-09-18 | 鸿富锦精密工业(武汉)有限公司 | USB (Universal Serial Bus) signal amplification circuit |
| CN103941811A (en) * | 2013-01-23 | 2014-07-23 | 鸿富锦精密工业（深圳）有限公司 | Notebook computer |
| CN103257944A (en) * | 2013-04-24 | 2013-08-21 | 江苏沁恒股份有限公司 | Method and device for long-distance transmission of USB signals |
| CN104135148A (en) * | 2014-07-17 | 2014-11-05 | 青岛歌尔声学科技有限公司 | USB (Universal Serial Bus) interface circuit |
| CN106610907A (en) * | 2015-10-26 | 2017-05-03 | 鸿富锦精密工业(武汉)有限公司 | Signal conversion circuit and communication system applying same |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114579492A (en) * | 2022-02-18 | 2022-06-03 | 长沙朗源电子科技有限公司 | Port signal switching control circuit |
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