阅读说明：本技术 Usb接口电路 (USB interface circuit ) 是由 彭章龙 于 2020-04-30 设计创作，主要内容包括：本发明提供一种USB接口电路,设置于一主板上,所述主板用于与USB设备进行通信连接,所述USB接口电路包括USB连接器、转接驱动器、主控芯片及第一滤波电路；所述USB连接器用于与所述USB设备进行插接以建立电性连接；所述转接驱动器电性连接于所述USB连接器与所述主控芯片之间；及所述第一滤波电路电性连接于所述主控芯片及所述转接驱动器之间,所述滤波电路用于滤除所述主控芯片与所述转接驱动器之间的共模干扰,本申请通过第一滤波电路滤除所述转接驱动器与所述主控芯片之间的共模干扰,以防止因转接驱动器与所述主控芯片不兼容而影响USB接口电路与USB设备之间的信号质量。(The invention provides a USB interface circuit, which is arranged on a mainboard, wherein the mainboard is used for being in communication connection with USB equipment, and the USB interface circuit comprises a USB connector, a transfer driver, a main control chip and a first filter circuit; the USB connector is used for being plugged with the USB equipment to establish electrical connection; the adapter driver is electrically connected between the USB connector and the main control chip; and first filter circuit electric connection in main control chip reaches between the through connection driver, filter circuit is used for the filtering main control chip with common mode interference between the through connection driver, this application through first filter circuit filtering through the through connection driver with common mode interference between the main control chip to prevent because of through connection driver with main control chip is incompatible and influences the signal quality between USB interface circuit and the USB equipment.)

1. A USB interface circuit is arranged on a mainboard, and the mainboard is used for being in communication connection with USB equipment;

the USB connector is used for being plugged with the USB equipment to establish electrical connection;

the adapter driver is electrically connected between the USB connector 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 first filter circuit is electrically connected between the main control chip and the adapter driver, and the filter circuit is used for filtering common-mode interference between the main control chip and the adapter driver.

2. The USB interface circuit of claim 1, further comprising a second filter circuit electrically connected between the USB connector and the adaptor driver for filtering common mode interference between the USB connector and the adaptor driver.

3. The USB interface circuit of claim 2, wherein the first 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 adaptor driver and the first signal sending pin of the main control chip, the second capacitor is connected between the second signal receiving pin of the adaptor driver and the second signal sending pin of the main control chip, 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.

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 2, wherein the USB connector is a Type-C connector.

6. The USB interface circuit of claim 5, further comprising a multiplexer electrically connected between the USB connector and the redriver.

7. The USB interface circuit of claim 6, wherein the second 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 transmitting pin of the multiplexer, the fourth capacitor is connected between the second signal receiving pin of the adaptor driver and the second signal transmitting 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.

Technical Field

The invention relates to the technical field of USB interface application, in particular to a Type-C interface circuit.

Background

Type-C is a brand-new USB interface form, and this interface can support positive reverse grafting, has very big convenience in the use, and present wide application in electronic equipment, in order to realize the high-speed transmission of signal in the current USB circuit, mostly have the compatibility problem among the Type-C interface circuit, lead to influencing USB circuit signal transmission quality, the USB equipment that interface circuit can't discern partial grafting even.

Disclosure of Invention

Accordingly, there is a need for a USB interface circuit that effectively identifies USB devices.

A USB interface circuit is arranged on a mainboard, the mainboard is used for being in communication connection with USB equipment, and the USB interface circuit comprises a USB connector, a transfer driver, a main control chip and a first filter circuit;

the USB connector is used for being plugged with the USB equipment to establish electrical connection;

the adapter driver is electrically connected between the USB connector 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 first filter circuit is electrically connected between the main control chip and the adapter driver, and the filter circuit is used for filtering common-mode interference between the main control chip and the adapter driver.

Furthermore, the USB interface circuit further includes a second filter circuit electrically connected between the USB connector and the adaptor driver for filtering out common mode interference between the USB connector and the adaptor driver.

Further, the first 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 main control chip, the second capacitor is connected between the second signal receiving pin of the adaptor driver and the second signal sending pin of the main control chip, 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 connector is a Type-C connector.

Further, the USB interface circuit further includes a multiplexer electrically connected between the USB connector and the adaptor driver.

Further, the second 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.

The first filter circuit is arranged between the adapter driver and the main control chip of the USB interface circuit, so that common mode interference between the adapter driver and the main control chip is filtered, and signal quality between the USB interface circuit and USB equipment is prevented from being influenced due to incompatibility of the adapter driver and the main control chip.

Drawings

FIG. 1 is a block diagram of an embodiment of a USB interface circuit according to the present invention.

Fig. 2 is a partial circuit diagram of the USB interface circuit in fig. 1.

FIG. 3 is a block diagram of another embodiment of a USB interface circuit according to the present invention.

Fig. 4 is a partial circuit diagram of the USB interface circuit in fig. 3.

Description of the main elements

USB interface circuit 100

Main board 110

USB connector 11

Adaption driver 12

Master control chip 13

First filter circuit 14

Multiplexer 15

Second filter circuit 16

USB device 200

Nodes P0, P1, P2, P3, P4, P5

Capacitors C1, C2, C3 and C4

Resistors R1, R2, R3 and R4

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 of the present invention will be described in detail with reference to the accompanying drawings and embodiments.

Referring to fig. 1, the present invention provides a USB interface circuit 100, wherein the USB interface circuit 100 is disposed on a motherboard 110, and the motherboard 110 is used for communicating with a USB device 200.

In this embodiment, the main board 110 is a main board of a main device, such as a PC main board +, a notebook computer main board, and the like. The USB device 200 is a slave device, such as a USB disk, a mouse, a camera, a display, and the like.

The USB interface circuit 100 includes a USB connector 11, a transition driver 12, a main control chip 13, and a first filter circuit 14. The USB connector 11 is electrically connected to an interface of the USB device 200, so that the motherboard 110 can communicate with the USB device 200.

In this embodiment, the USB connector 11 is a Type-C interface, and can be plugged in forward and reverse directions.

The adaptor driver 12 is electrically connected between the USB connector 11 and the main control chip 13.

The first filter circuit 14 is electrically connected to a node P0 between the main control chip 13 and the through driver 12.

The through driver 12 is configured to amplify a signal transmitted between the USB device 200 and the main control chip 13 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.

The Redriver (driver), also known as a Repeater IC, may regenerate signals for increased signal quality on high-speed interfaces.

For example, the USB device 200 sends a first signal to the adaptor driver 12 through the USB connector 11, the first signal is transmitted through a cable, the first signal is attenuated by a certain coefficient in the transmission process, after receiving the first signal, the adaptor driver 12 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 13, 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 13 and the USB device 200 will be realized.

The USB connector 11 transmits signals to the adaptor driver 12 through a pair of differential signal lines, so that common mode interference occurs during the transmission of signals from the USB connector 11 to the adaptor driver 12, which may result in the inability to identify the plugged USB device 200.

In this embodiment, the first filter circuit 14 is configured to filter a common mode interference between the main control chip 13 and the adaptor driver 12, so as to prevent the main control chip 13 and the adaptor driver 12 from being compatible with each other and affecting the quality of signals transmitted between the USB interface circuit 100 and the USB device 200.

Referring to fig. 2, the first filter circuit 14 includes a first capacitor C1, a second capacitor C2, a first resistor R1 and a second resistor R2. The main control chip 13 includes a pair of signal transmission pins TX _ DP and TX _ DN, and the through driver 12 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 12 are electrically connected to the signal sending pins TX _ DP and TX _ DN of the main control chip 13, respectively, and are configured to receive signals transmitted by the main control chip 13.

In this embodiment, the first capacitor C1 is connected between the signal transmitting pin TX _ DP and the signal receiving pin RXA _ DP. One end of the first resistor R1 is connected to the node P2 between the first capacitor C1 and the signal transmission pin TX _ DP, and the other end of the first resistor R1 is grounded. The second capacitor C2 is connected between the signal transmission pin TX _ DN and the signal reception pin RXA _ DN. One end of the second resistor R2 is connected to a node P3 between the second capacitor C2 and the signal transmission pin TX _ DN, and the other end of the second resistor R2 is grounded.

The first capacitor C1 and the 1 resistor R1 form a first RC filter unit, and the second capacitor C2 and the second 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 main control chip 13 and the through driver 12.

In one embodiment, the capacitance values of the first capacitor C1 and the second capacitor C2 are preferably 330nF, and the resistance values of the first resistor R1 and the second resistor R2 are preferably 220 kohm.

Further, the USB interface circuit 100 further includes a second filter circuit 16, the second filter circuit 16 is electrically connected to a node P1 between the USB connector 11 and the adaptor driver 12, and the second filter circuit 16 is configured to filter out a common mode interference between the USB connector 11 and the adaptor driver 12.

Further, referring to fig. 3, in another embodiment, the USB interface circuit 100 further includes a multiplexer 15. The multiplexer 15 is electrically connected between the USB connector 11 and the node P1.

In this embodiment, the USB connector 11 is a Type-C interface.

Referring to fig. 4, the second filter circuit 16 includes a third capacitor C3, a fourth capacitor C4, a third resistor R3 and a fourth resistor R4. The USB connector 11 includes signal receiving pins RX1_ DP, RX1_ DN, RX2_ DP, and RX2_ DN. The USB connector 11 also includes signaling pins TX1_ DP, TX1_ DN, TX2_ DP, and TX2_ DN. The multiplexer 15 includes signal receiving pins DB _ a1, DB _ b1, DB _ a2, and DB _ b 2. The multiplexer 15 also includes signal transmission pins DB _ a and DB _ b. The signal transmitting pins DB _ a and DB _ b of the multiplexer 15 are respectively communicatively connected to the signal receiving pins RXA _ DP and RXA _ DN of the through driver 12.

When the USB device 200 is plugged into the USB connector 11 in a first plugging manner, that is, the USB device 200 is electrically connected to the signal receiving pins RX _ DP and RX _ DN of the USB connector 11, the signal receiving pins DB _ a1 and DB _ b1 of the multiplexer 15 are respectively connected to the signal sending pins TX _ DP and TX _ DN of the USB connector 11 in a communication manner.

When the USB apparatus 200 is plugged into the USB connector 11 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 connector 11, the signal receiving pins DB _ a2 and DB _ b2 of the multiplexer 15 are respectively connected to the signal sending pins TX2_ DP and TX2_ DN of the USB connector 11 in a communication manner. The USB apparatus 200 is plugged into the USB connector 11 by a first plugging method or a second plugging method, and the USB apparatus 200 can transmit signals to the adaptor driver 12 through the USB connector 11 and the multiplexer 15.

In this embodiment, the third capacitor C3 is connected between the signal receiving pin RXA _ DP and the signal transmitting pin DB _ a. One end of the third resistor R3 is connected to the node P4 between the third capacitor C3 and the signal transmission pin DB _ a, and the other end of the third resistor R3 is grounded. The fourth capacitor C4 is connected between the signal receiving pin RXA _ DN and the signal transmitting pin DB _ b. One end of the fourth resistor R4 is connected to the node P5 between the fourth capacitor C4 and the signal transmission pin DB _ b, and the other end of the fourth resistor R4 is grounded.

The third capacitor C3 and the third resistor R3 form a third RC filter unit, and the fourth capacitor C4 and the fourth resistor R4 form a fourth RC filter unit. The third RC filter unit and the fourth RC filter unit can effectively filter the common mode interference between the multiplexer 15 and the redriver 12.

The USB interface circuit 100 is configured with the first filter circuit 14 between the adaptor driver 12 and the main control chip 13 to filter out common mode interference between the adaptor driver 12 and the main control chip 13, so as to prevent signal quality between the USB interface circuit 100 and the USB device 200 from being affected due to incompatibility between the adaptor driver 12 and the main control chip 13.

Further, the USB interface circuit 100 further includes a multiplexer 15, a node between the multiplexer 15 and the redriver 12 is provided with a second filter circuit 16, and the second filter circuit 16 is configured to filter out common mode interference between the multiplexer 15 and the redriver 12.

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.