Expansion circuit and expansion device of USB interface

Abstract

The utility model discloses an expansion circuit and an expansion device of a USB (Universal Serial Bus) interface, which are characterized in that a boost chip and a buck chip are connected in series between a data pin of a USB uplink interface and a data pin of a USB downlink interface, so that when the voltage input by the USB uplink interface is too high or too low, the voltage is adjusted by the boost chip and the buck chip, and then the data pin of the USB downlink interface is expanded. Finally, the voltage output by the USB downlink interface can meet the requirement, and the voltage adaptation capability of the USB interface is improved. The overvoltage protection chip is arranged at the USB uplink interface, so that the safety of voltage input is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to USB interface peripheral equipment field especially, it relates to an extension circuit and extension device of USB interface. BACKGROUND

[0002] At present, since the USB expansion dock on the market can only support single 5V voltage input, and does not protect the interface voltage input, due to the practical problems such as misplug, there may be high-voltage power input, resulting in equipment damage. And the selection range of single power voltage to Host equipment is not the maximum. Specifically, there are various types of USB interface expansion dock products on the market at present, but basically only meet the demand of data transmission, and the power input voltage of the expansion dock needs to be fixed as 5V to work normally. In addition, due to the output voltage of some Host equipment is not 5V, resulting in that the selection of Host equipment by the expansion dock is not extensive. And no corresponding electrical protection is made for the interface, resulting in that the protection of Host equipment and Dceive equipment is not comprehensive enough.

[0003] Therefore, the voltage adaptation capability of the existing USB expansion dock needs to be improved and improved. UTILITY MODEL CONTENTS

[0004] In view of the above technical problems, the extension circuit and extension device of USB interface provided by the utility model aim to improve the voltage adaptation capability of USB interface extension.

[0005] An embodiment provides an extension circuit of USB interface, comprising: a USB uplink interface, at least one USB downlink interface, an overvoltage protection chip, a boost chip and a step-down chip;

[0006] The data pin of the USB uplink interface is connected with the data pin of the USB downlink interface;

[0007] The VBUS pin of the USB uplink interface is connected with the input end of the overvoltage protection chip, the output end of the overvoltage protection chip is connected with the input end of the step-down chip through the boost chip, and the output end of the step-down chip is connected with the VBUS pin of the USB downlink interface;

[0008] The overvoltage protection chip is used for disconnecting the circuit itself to carry out overvoltage protection when the voltage of the VBUS pin of the USB uplink interface exceeds a preset first voltage threshold;

[0009] The boost chip is used for boosting the voltage output by the overvoltage protection chip when the voltage output by the overvoltage protection chip is lower than a preset second voltage threshold;

[0010] The buck chip is configured to reduce the voltage output by the boost chip to a preset target range; wherein the first voltage threshold is higher than the maximum value of the target range, and the second voltage threshold is lower than the minimum value of the target range.

[0011] The buck chip is configured to reduce the voltage output by the boost chip to a preset target range; wherein the first voltage threshold is higher than the maximum value of the target range, and the second voltage threshold is lower than the minimum value of the target range.

[0012] The overcurrent protection chip is configured to disconnect its own circuit to perform overcurrent protection when the current of the VBUS pin of the USB downstream interface exceeds a preset current threshold.

[0013] The buck chip is configured to reduce the voltage output by the boost chip to a preset target range; wherein the first voltage threshold is higher than the maximum value of the target range, and the second voltage threshold is lower than the minimum value of the target range.

[0014] The data pin of the USB upstream interface is connected to the data pins of the N USB downstream interfaces through the USB extension chip.

[0015] The USB extension chip is configured to expand the signal of the data pin of the USB upstream interface into N groups of signals and output to the data pins of the N USB downstream interfaces, respectively.

[0016] The buck chip is configured to reduce the voltage output by the boost chip to a preset target range; wherein the first voltage threshold is higher than the maximum value of the target range, and the second voltage threshold is lower than the minimum value of the target range.

[0017] The first common-mode inductor is connected in series between the data pin of the USB upstream interface and the USB extension chip.

[0018] The buck chip is configured to reduce the voltage output by the boost chip to a preset target range; wherein the first voltage threshold is higher than the maximum value of the target range, and the second voltage threshold is lower than the minimum value of the target range.

[0019] One of the second common-mode inductors is connected in series between the data pin of one of the USB downstream interfaces and the USB extension chip.

[0020] The buck chip is configured to reduce the voltage output by the boost chip to a preset target range; wherein the first voltage threshold is higher than the maximum value of the target range, and the second voltage threshold is lower than the minimum value of the target range.

[0021] The buck chip is configured to reduce the voltage output by the boost chip to a preset target range; wherein the first voltage threshold is higher than the maximum value of the target range, and the second voltage threshold is lower than the minimum value of the target range.

[0022] In an embodiment, the overvoltage protection chip is an adjustable overvoltage protection chip, the overcurrent protection chip is an adjustable overcurrent protection chip, the first voltage threshold is 14V, and the number of the USB downstream interfaces is 3; the type of the USB upstream interface is the same as or different from the type of the USB downstream interface, and the types of the USB downstream interfaces are the same as or different from each other; the extension circuit further comprises an electrostatic tube and / or a short-circuit detection protection chip; the electrostatic tube is connected to a data pin of the USB upstream interface or the USB downstream interface; the short-circuit detection protection chip is connected in series between a VBUS pin of the USB downstream interface and the overcurrent protection chip 50, or between the voltage reduction chip and the overcurrent protection chip, and is used to disconnect the circuit itself when a short circuit is detected.

[0023] In an embodiment, the extension device of the USB interface comprises a shell and a circuit board arranged in the shell, and the extension circuit described above is arranged on the circuit board.

[0024] In an embodiment, the USB upstream interface and the at least one USB downstream interface are exposed to the shell.

[0025] The extension circuit and the extension device of the USB interface provided by the embodiments of the present application can adjust the voltage through the voltage reduction chip and the voltage increase chip when the voltage input by the USB upstream interface is too high or too low, so that the voltage output by the USB downstream interface can meet the requirements, and the voltage adaptation capability of the USB interface is improved. The overvoltage protection chip arranged at the USB upstream interface improves the safety of voltage input. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 FIG. 1 is a structural block diagram of an embodiment of the extension circuit of the USB interface provided by the present application;

[0027] Figure 2 FIG. 1 is a structural block diagram of an embodiment of the extension circuit of the USB interface provided by the present application; DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0029] The utility model discloses to the technical problem mentioned in the prior art, the compatibility of adjustable wide voltage input of the design is more extensive to the output voltage of Host equipment not same, and the use range is wider. And input voltage can also work normally in the high voltage range of setting, and it is not worried that product is damaged because of voltage anomaly caused by various external reasons such as misplug. The following will be described in detail through some embodiments.

[0030] As Figure 1 And 2 The utility model provides an extension circuit of USB interface, including: a USB uplink interface 10, at least one USB downlink interface 70, overvoltage protection chip 20, boost chip 30 and step-down chip 40.

[0031] The data pin of USB uplink interface 10 is connected with the data pin of USB downlink interface 70. The data pin is used for transmitting data. The USB uplink interface 10 and the USB downlink interface 70 can be various types of USB interfaces, such as USB-A interface, USB-B interface, Micro USB interface, etc. In the embodiment, the data pin includes D+ pin (positive data pin) and D- pin (negative data pin). In another embodiment, the USB uplink interface 10 and the USB downlink interface 70 are both USB Type-C interfaces, and the data pin thereof can include D+ pin and D- pin, such as A6, B6, A7, B7 pins of USB Type-C interface, and can also include TX pin and RX pin, etc. In another embodiment, although the USB uplink interface 10 and the USB downlink interface 70 are both USB interfaces, they can be of different types, such as the USB uplink interface 10 being a Type-C interface and the USB downlink interface 70 being a USB-A interface, a USB-B interface or a Micro USB interface, or the USB uplink interface 10 being a USB-A interface, a USB-B interface or a Micro USB interface and the USB downlink interface 70 being a Type-C interface, etc. When there are multiple USB downlink interfaces 70, the types of the USB downlink interfaces can be the same or different, thereby forming various combinations for the extension of different types of USB interfaces. The USB uplink interface 10 can be connected to a computer or other Host device terminal. The USB downlink interface 70 can be connected to a U disk or other Device equipment.

[0032] The VBUS pin (also known as the positive power pin or power supply pin) of the USB uplink interface 10 is connected to the input end of the overvoltage protection chip (OVP protection chip) 20, the output end of the overvoltage protection chip 20 is connected to the input end of the step-down chip 40 through the boost chip 30, and the output end of the step-down chip 40 is connected to the VBUS pin of the USB downlink interface 70.

[0033] The overvoltage protection chip 20 is used for disconnecting the circuit itself for overvoltage protection when the voltage of the VBUS pin of the USB uplink interface 10 exceeds a preset first voltage threshold. In the embodiment, the overvoltage protection chip 20 is an adjustable overvoltage protection chip, that is, the first voltage threshold is adjustable, which can be adjusted according to needs. In an embodiment, the first voltage threshold can be 14V, and of course can also exceed 14V. The adjustable overvoltage protection chip is responsible for real-time monitoring of the voltage input by the USB uplink interface 10, and when it is monitored that the input voltage is higher than the set first voltage threshold, the input power is cut off to protect the subsequent circuit. It can be seen that the expansion circuit provided by the utility model has a built-in high-voltage protection chip, can provide nanosecond-level protection against lightning surges and the like, and improves safety. The overvoltage protection chip 20 can be, for example, an overvoltage protection chip with a model number of WS3221C or 74LV4052PW.

[0034] The boost chip 30 is used for boosting the voltage output by the overvoltage protection chip 20 when the voltage output by the overvoltage protection chip 20 is lower than a preset second voltage threshold. The second voltage threshold is preset according to needs, and can be, for example, 5V, 4V, etc. In the embodiment, the boost chip 30 is a DC-DC boost chip. The boost chip 30 can be, for example, a DC-DC boost chip with a model number of SY7208, LP6222 or AP2008.

[0035] The buck chip 40 is used for bucking the voltage output by the boost chip 30 to a preset target range; wherein the first voltage threshold is higher than the maximum value of the target range, and the second voltage threshold is lower than the minimum value of the target range. The target range can be set according to needs, and in the embodiment, the target range is 5V±0.25V. In the embodiment, the buck chip 40 is a DC-DC buck chip. The buck chip 40 can be, for example, a DC-DC buck chip with a model number of ETA8121, SW3820 or SY8121.

[0036] It can be seen that through the cooperation of the overvoltage protection chip 20, the boost chip 30 and the buck chip 40, as long as the input voltage does not exceed the first voltage threshold, the expansion circuit can normally receive and process to output a voltage (such as 5V) of a USB interface, thereby expanding the voltage adaptation range of the expansion circuit. That is, the expansion circuit provided by the utility model supports wide voltage input, so that the expansion circuit is not limited to use with a 5V output Host device such as a computer.

[0037] In an embodiment, the extension circuit further comprises over-current protection chips (OCP protection chips) 50. The output end of the buck chip 40 is connected to the VBUS pin of the USB downstream interface 70 through the OCP protection chip 50. The number of OCP protection chips 50 is usually the same as the number of USB downstream interfaces 70, and one OCP protection chip 50 is connected to one USB downstream interface 70, so that the current flowing into each USB downstream interface 70 can be effectively protected.

[0038] The OCP protection chip 50 is used to disconnect its own circuit when the current of the VBUS pin of the USB downstream interface 70 exceeds the preset current threshold to perform over-current protection. The current threshold can be set as needed. In this embodiment, the OCP protection chip 50 is an adjustable over-current protection chip, that is, the current threshold is adjustable and can be adjusted as needed. The adjustable over-current protection chip is responsible for current monitoring of the USB downstream interface 70, and when it is monitored that the current of the USB downstream interface 70 is greater than the current threshold, the output power supply is cut off to protect the front-end circuit. The external device is limited by the OCP protection chip 50, so that the extension circuit works more stably. The OCP protection chip 50 may, for example, be an over-current protection chip with a model number of WS4618E, BL2555, or SGM2576.

[0039] The number of USB downstream interfaces 70 in the extension circuit can be one or multiple, and the latter is taken as an example for description in this embodiment. Specifically, the number of USB downstream interfaces 70 in the extension circuit is N, and N is an integer greater than 1. The extension circuit further comprises a USB extension chip 60.

[0040] The data pin of the USB upstream interface 10 is connected to the data pin of the N USB downstream interfaces through the USB extension chip 60.

[0041] The USB extension chip 60 is used to expand the signal of the data pin of the USB upstream interface 10 into N groups of signals and output them to the data pin of the N USB downstream interfaces 70, respectively. As shown in Figure 2 The USB extension chip 60 has a group of input ends connected to the D+ pin and the D- pin of the USB upstream interface 10. The USB extension chip 60 has N groups of output ends, and each group of output ends is connected to the D+ pin and the D- pin of one USB downstream interface 70. As shown in Figure 2 In the embodiment shown in

[0042] The extension circuit can further comprise a first common mode inductor L1. The first common mode inductor L1 is connected in series between a data pin of the USB uplink interface 10 and the USB extension chip 60. The common mode inductor L1 can filter electromagnetic interference signals.

[0043] The extension circuit further comprises N second common mode inductors L2. One second common mode inductor L2 is connected in series between a data pin of one USB downlink interface 70 and the USB extension chip 60. That is, a group of output terminals of the USB extension chip 60 are connected to the D+ pin and the D- pin of one USB downlink interface 70 through one second common mode inductor L2. It can be seen that the outputs of the three USB downlink interfaces 70 do not interfere with each other, and each is independently protected, so that the use is more secure.

[0044] The extension circuit can further comprise an electrostatic tube (such as a USB special electrostatic tube). The electrostatic tube is connected to the data pin of the USB uplink interface 10 and can also be connected to the data pin of the USB downlink interface 70. The electrostatic tube can protect the USB uplink interface 10 and the USB interface of the Host end, and can also protect the external USB device from static interference, so that the data transmission is more stable.

[0045] The extension circuit can further comprise a short-circuit detection protection chip. The short-circuit detection protection chip can be connected in series between the VBUS pin of the USB downlink interface 70 and the overcurrent protection chip 50, or can be connected in series between the voltage reduction chip 40 and the overcurrent protection chip 50. The short-circuit detection protection chip is used to disconnect the circuit itself when a short circuit is detected, so as to protect the USB interface of the Host end and the power supply of the extension circuit from being damaged.

[0046] It can be seen that the extension circuit provided by the utility model optimizes the shortcomings of various USB expansion docks on the market. By being compatible with wide voltage input, the application of the USB expansion dock is expanded, and more Host devices with different output voltages can be compatible. By adding high-response OVP chips and OCP chips for USB interface protection, the expensive devices are sufficiently protected.

[0047] Based on the above-mentioned extension circuit, the utility model further provides an extension device of a USB interface, which comprises a shell and a circuit board arranged in the shell. The circuit board is provided with the above-mentioned extension circuit. The extension device is small and convenient to carry, and can be used with various devices having a USB interface. In an embodiment, the USB uplink interface 10 and the USB downlink interfaces 70 are exposed to the shell, so as to be convenient for plug and play.

[0048] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some technical features therein can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An extension circuit of a USB interface, characterized in that, The application relates to an expansion circuit for a USB (Universal Serial Bus) interface. The expansion circuit comprises a USB uplink interface, at least one USB downlink interface, an overvoltage protection chip, a voltage boosting chip and a voltage reducing chip. A data pin of the USB uplink interface is connected to a data pin of the USB downlink interface. A VBUS pin of the USB uplink interface is connected to an input end of the overvoltage protection chip, an output end of the overvoltage protection chip is connected to an input end of the voltage reducing chip through the voltage boosting chip, and an output end of the voltage reducing chip is connected to a VBUS pin of the USB downlink interface. The overvoltage protection chip is used for disconnecting the circuit of the overvoltage protection chip to perform overvoltage protection when the voltage of the VBUS pin of the USB uplink interface exceeds a preset first voltage threshold. The voltage boosting chip is used for boosting the voltage output by the overvoltage protection chip when the voltage output by the overvoltage protection chip is lower than a preset second voltage threshold. The voltage reducing chip is used for reducing the voltage output by the voltage boosting chip to a preset target range; wherein the first voltage threshold is higher than the maximum value of the target range, and the second voltage threshold is lower than the minimum value of the target range.

2. The extension circuit of claim 1, wherein, The expansion circuit further comprises an overcurrent protection chip, and the output end of the voltage reducing chip is connected to the VBUS pin of the USB downlink interface through the overcurrent protection chip. The overcurrent protection chip is used for disconnecting the circuit of the overcurrent protection chip to perform overcurrent protection when the current of the VBUS pin of the USB downlink interface exceeds a preset current threshold.

3. The extension circuit according to claim 1 or 2, characterized in that, The at least one USB downlink interface comprises N USB downlink interfaces, and N is an integer greater than 1; the expansion circuit further comprises a USB expansion chip. The data pin of the USB uplink interface is connected to the data pins of the N USB downlink interfaces through the USB expansion chip. The USB expansion chip is used for expanding the signal of the data pin of the USB uplink interface into N groups of signals and outputting the N groups of signals to the data pins of the N USB downlink interfaces, respectively.

4. The extension circuit of claim 3, wherein, The expansion circuit further comprises a first common-mode inductor. The first common-mode inductor is connected in series between the data pin of the USB uplink interface and the USB expansion chip.

5. The extension circuit of claim 4, wherein, The expansion circuit further comprises N second common-mode inductors. One of the second common-mode inductors is connected in series between the data pin of one of the USB downlink interfaces and the USB expansion chip.

6. The extension circuit of claim 1, wherein, The data pin comprises a D+ pin and a D- pin.

7. The extension circuit of claim 1, wherein, The target range is 5V+ / -0.25V.

8. The extension circuit of claim 2, wherein, The overvoltage protection chip is an adjustable overvoltage protection chip, the overcurrent protection chip is an adjustable overcurrent protection chip, the first voltage threshold is 14V, and the number of the USB downstream interfaces is 3; the type of the USB upstream interface is the same as or different from the type of the USB downstream interface, and the types of the USB downstream interfaces are the same as or different from each other; the extension circuit further comprises an electrostatic tube and / or a short-circuit detection protection chip; the electrostatic tube is connected with a data pin of the USB upstream interface or the USB downstream interface; the short-circuit detection protection chip is connected in series between a VBUS pin of the USB downstream interface and the overcurrent protection chip 50 or between the voltage reduction chip and the overcurrent protection chip, and is used for disconnecting a self circuit when a short circuit is detected.

9. An extension device for a USB interface, comprising: The housing and the circuit board arranged in the housing are characterized in that the extension circuit as claimed in any one of claims 1-8 is arranged on the circuit board.

10. The extension device of claim 9, wherein, The USB upstream interface and the at least one USB downstream interface are exposed to the housing.

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