WO2020048276A1

WO2020048276A1 - Charging interface protection method and charging device

Info

Publication number: WO2020048276A1
Application number: PCT/CN2019/099320
Authority: WO
Inventors: 曾海军
Original assignee: 中兴通讯股份有限公司
Priority date: 2018-09-04
Filing date: 2019-08-05
Publication date: 2020-03-12
Also published as: CN110875614A

Abstract

The present application discloses a charging interface protection method and a charging device, the method comprising: comparing a voltage of a first pin of a charging interface with a reference voltage, and obtaining a first control signal on the basis of a comparison result (101); and controlling, on the basis of the first control signal, whether or not a second pin of the charging interface connects to ground.

Description

Protection method and charging device for charging interface

cross reference

This application refers to Chinese Patent Application No. 201811028330.6, entitled “A Protection Method and Charging Device for Charging Interface”, filed on September 4, 2018, which is incorporated by reference in its entirety.

Technical field

The present application relates to circuit protection technology, and in particular, to a protection method and a charging device for a charging interface.

Background technique

At present, most mobile terminals use universal serial bus (USB, Universal Serial Bus) interfaces or TPYE C interfaces, and a few use non-standard interfaces. No matter it is a USB interface or a TPYE interface, there are signal pins on the periphery of the charging pin (VBUS / VCHG pin). After the mobile terminal is used for a period of time, the interface will enter the dust phenomenon, or even Water ingress is likely to cause a short circuit or short circuit between VBUS / VCHG pin and the adjacent signal pin. In addition, when the user inserts the data cable, it may cause a short circuit between the VBUS / VCHG pin and the adjacent signal pin, causing some functions to fail, or even the mobile terminal being unusable, causing dissatisfaction or complaints from the mobile terminal user. This situation The TPYE C interface is more obvious, because the TPYE C interface has more pins, and the distance between the pins is smaller. Compared to the conventional USB interface, the above situation is more likely to occur.

Summary of the Invention

The embodiments of the present application provide a protection method and a charging device for a charging interface.

The method for protecting a charging interface provided in the embodiment of the present application includes: comparing a voltage of a first pin of the charging interface with a reference voltage, and obtaining a first control signal based on a comparison result; and controlling the first control signal based on the first control signal. Whether the second pin of the charging interface is connected to ground.

The charging device provided in the embodiment of the present application includes: a charging interface; a comparison circuit for comparing a voltage of a first pin of the charging interface with a reference voltage, and outputting a first control signal based on a comparison result; The first control signal controls whether the second pin of the charging interface is connected to ground.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings generally illustrate various embodiments discussed herein by way of example and not limitation.

FIG. 1 is a first flowchart of a method for protecting a charging interface according to an embodiment of the present application; FIG.

FIG. 2 is a schematic diagram of a comparator provided in an embodiment of the present application; FIG.

3 is an output diagram of a working principle of a comparator provided in an embodiment of the present application;

4 is a connection structure diagram of a single comparator and a charging interface according to an embodiment of the present application;

5 is a connection structure diagram of a multi-channel comparator, a charging interface, and a transistor provided in an embodiment of the present application;

FIG. 6 is a schematic diagram of a voltage dividing circuit according to an embodiment of the present application; FIG.

7 is a schematic diagram of an output of a voltage divider circuit as an input of a comparator according to an embodiment of the present application;

8 is a second flowchart of a method for protecting a charging interface according to an embodiment of the present application;

FIG. 9 is a schematic structural diagram of a charging device according to an embodiment of the present application.

detailed description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, but not all of the embodiments.

Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

In order to facilitate understanding of the technical solutions of the embodiments of the present application, related technologies related to the embodiments of the present application are described below.

1) USB interface

The order of the pins of the USB interface is VBUS / VCHG, D- / DM, D + / DP, ID, and GND.

2) Simple TPYE C interface (supports USB2.0)

The order of the pins of the simple TPYE C interface is GND, VBUS / VCHG, CC2, NC, D + / DP, D- / DM, D + / DP, D- / DM, CC1, NC, VBUS / VCHG, GND.

3) TPYE C interface (supports USB2.0 and USB3.0)

The pins of the TPYE C interface include two rows. The order of the pins on the upper row is GND, TX1 +, TX-, VBUS / VCHG, CC1, D +, D-, SBU1, VBUS / VCHG, RX2-, RX2 +, GND. The order of the pins is GND, RX1 +, RX1-, VBUS / VCHG, SBU2, D-, D +, CC2, VBUS / VCHG, TX2-, TX2 +, GND.

From the arrangement order of the above interfaces, it can be seen that whether it is a USB interface or a TPYE C interface, there are signal pins around its VBUS / VCHG pins.

In the following embodiments of the present application, the second pin refers to a VBUS / VCHG pin, and is referred to as a charging pin.

The first pin refers to the signal pin around the VBUS / VCHG pin. Taking the USB interface as an example, the first pin can be D- / DM, D + / DP, etc. Taking the simple TPYE C interface as an example, the first pin can be CC2, NC, D + / DP, D- / DM, etc. Taking the TPYE C interface as an example, the first pin can be TX1 +, TX-, RX2-, RX2 +, and so on. It is worth noting that the first pin is not limited to the above example, and any pin that is prone to short circuit with the VBUS / VCHG pin can be used as the first pin. In order to avoid damage to the charging interface caused by a short circuit between the first pin and the second pin, the embodiments of the present application propose the following technical solutions.

In the technical solution of the embodiment of the present application, the voltage of the first pin of the charging interface and the reference voltage are compared, and a first control signal is output based on the comparison result; based on the first control signal, the second control signal of the charging interface is controlled. Whether the pin is connected to ground. With the technical solution of the embodiment of the present application, if a short circuit occurs between the second pin and the surrounding first pin, the voltage of the first pin will be higher than the reference voltage, thereby triggering the first control signal to achieve the second pin and The ground is connected, and the second pin is a charging pin (VBUS / VCHG pin). The solution of this embodiment adopts a pure hardware circuit to respond more quickly, thereby achieving faster protection of the charging interface, and also protecting the charging interface. Related charging circuit.

FIG. 1 is a first flowchart of a method for protecting a charging interface according to an embodiment of the present application. As shown in FIG. 1, the method for protecting a charging interface includes the following steps:

Step 101: Compare the voltage of the first pin of the charging interface with the reference voltage, and obtain a first control signal based on the comparison result.

In the embodiment of the present application, the voltage of the first pin of the charging interface and the reference voltage may be compared by a comparison circuit (also referred to as a comparator), and the voltage of the first pin of the charging interface may also be compared by a detection circuit. With the size of the reference voltage.

In the embodiment of the present application, the charging interface includes N first pins, where N is a positive integer. All N first pins of the charging interface are connected to a first input terminal of a comparison circuit, the reference voltage is connected to a second input terminal of the comparison circuit, and the N The voltage of the first pin and the reference voltage are compared respectively.

For example: N = 1, connect a first pin to the first input terminal of the comparison circuit, connect the reference voltage to the second input terminal of the comparison circuit, and compare the The voltage of one first pin is compared with the reference voltage. Here, the comparison circuit can be implemented by a single comparator.

For another example: N = 4, connect 4 first pins to the first input terminal of the comparison circuit, connect the reference voltage to the second input terminal of the comparison circuit, The voltages of the four first pins are compared with the reference voltage, respectively. Here, the comparison circuit can be implemented by a 4-way comparator.

In the embodiment of the present application, if the voltage of at least one of the N first pins is higher than the reference voltage, the output terminal of the comparison circuit outputs the first voltage; if the N If the voltage of the first pin is lower than the reference voltage, the output terminal of the comparison circuit outputs a second voltage; wherein the first voltage is higher than the second voltage.

Referring to FIG. 2, FIG. 2 is a schematic diagram of a comparator provided in an embodiment of the present application. The comparator may be a single-channel comparator or a multi-channel comparator. Among them, the high level of the comparator is defined as V +, the low level is defined as V-, the first input terminal (that is, the positive input terminal) of the comparator is defined as Vin +, and the second input terminal (that is, the negative input terminal) is defined Is Vin- and the output is defined as Vout.

Referring to FIG. 3, FIG. 3 is an output diagram of the working principle of the comparator provided in the embodiment of the present application, wherein the horizontal axis is the first input terminal (ie, the positive input terminal) Vin + of the comparator, and the vertical axis is the output of the comparator The terminals Vout, V + and V- are the high and low levels of the comparator. V- is 0 in Figure 3. In this embodiment, a non-inverting comparator is used. Vin- is the reference voltage. When Vin + is greater than Vin-, the output terminal Vout becomes High.

Referring to FIG. 4, FIG. 4 is a connection structure diagram of a single comparator and a charging interface according to an embodiment of the present application, where V + of the comparator is connected to VBUS, and V- is grounded; Vin- of the comparator is connected to a VBAT voltage signal or VBUS. The voltage divider circuit, Vin + of the comparator is connected to a signal adjacent to VBUS / VCHG. Figure 4 is signal A; the output of this comparator is used as the input signal of the control terminal (ie, the base) of the triode.

Step 102: Control whether the second pin of the charging interface is connected to ground based on the first control signal.

In the embodiment of the present application, an output terminal of the comparison circuit is connected to a control terminal of a switching circuit, and the conducting state of the switching circuit is controlled by the first control signal; wherein, if the first control signal has a first A voltage, the switch circuit is in an on state, and the second pin of the charging interface is connected to ground; if the first control signal has a second voltage, the switch circuit is in an off state, the The second pin of the charging interface is not connected to ground; wherein the first voltage is higher than the second voltage.

In the above solution, the switching circuit is a triode or a field effect MOS transistor.

Referring to FIG. 5, FIG. 5 is a connection structure diagram of a multi-channel comparator, a charging interface, and a transistor provided in an embodiment of the present application, where A is a charging interface (also called a connector), and the type of the charging interface is not limited. It is a SUB interface, it can also be a TYPE interface, or a non-standard interface. B is a comparator and C is a transistor. Figure 5 uses the TYPE interface as an example. The number of the second pins is two, which correspond to VBUS in the upper row and VBUS in the lower row, respectively. The first pins near the upper row of VBUS include signal A and signal B. The first pins near the lower row of VBUS include signal C and signal D.

Usually, when VBUS and signal A and signal B are not short-circuited, the output of the comparator is low and the transistor is cut off. When VBUS and signal A and / or signal B are short-circuited or micro-short-circuited, the input of Vin + of the comparator The voltage becomes VBUS voltage, and the VBUS voltage is greater than the Vin- voltage. At this time, the output of the above comparator becomes high level, so as to control the transistor to turn on and turn off the charging to protect the charging interface and the corresponding circuit on the circuit board (including IC) purpose. The pins of the above row are taken as an example, the pins of the lower row are the same as those of the upper row.

In the above solution of the embodiment of the present application, the reference voltage is less than the voltage of the second pin. The reference voltage may be a VBAT voltage or a divided voltage of a VBUS voltage. Referring to FIG. 6, FIG. 6 is a schematic diagram of a voltage dividing circuit provided in an embodiment of the present application, where the VBUS voltage is grounded through two resistors R1 and R2, Vr is output to the input terminal Vin- of the comparator (refer to Figure 7). R1 and R2 are K-level. The specific value can be adjusted according to the voltage of VBUs.

This embodiment breaks the original conventional design scheme, and connects the signal pin adjacent to VBUS / VCHG pin at the USB connector or TPYE C connector or other connector to the voltage comparator, and at the same time, one of the VBUS / A transistor is added between VCHG pin and GND. The output of the voltage comparator is used to control the on and off of this transistor, so as to quickly turn off the charging to protect the USB connector, TPYE connector or other connectors and the circuit board. Related circuits finally achieve the purpose of protecting mobile terminal equipment.

FIG. 8 is a second flowchart of a method for protecting a charging interface according to an embodiment of the present application. The method of the embodiment of the present application is applied to a charging interface (also referred to as a connector), such as a USB interface, a TPYE interface, etc. The protection method of the charging interface includes the following steps:

Step 801: Connect the signal pin of the charging interface adjacent to the VBUS / VCHG pin.

Here, if there are multiple signal pins, these multiple signal pins need to be all connected.

Step 802: Select an appropriate voltage comparator according to the number of signal pins adjacent to VBUS / VCHG pin.

Here, the voltage comparator may be a single voltage comparator or a multi-channel voltage comparator. V + of the voltage comparator is connected to VBUS and V- is grounded.

Step 803: The pin signal received in step 801 is correspondingly connected to Vin + of a single or multiple voltage comparator.

Step 804: Connect the divided voltage of Vbat or VBUS to the input Vin- of the single or multiple voltage comparators.

Step 805: Select a suitable transistor, and connect the comparator output to the control terminal (base) of the transistor.

In this embodiment, an NPN type transistor can be selected.

Step 806: Connect the VBUS / VCHG pin on the charging interface to the collector terminal of the triode, and the emitter of the triode is grounded.

Step 807: Use the base of the triode to control the collector and the emitter to be turned off or on, so as to protect the charging interface and its internal circuit.

The following describes the protection process of the charging interface in the embodiment of the present application with two scenarios where a short circuit occurs in the charging interface and the mobile phone battery runs out of power.

Scenario 1: Water inlet causes a short circuit in the charging interface. Refer to Figure 2 to Figure 5. The short circuit of water inlet is that signal A and VBUS are shorted. At this time, the voltage of signal A will become the voltage of VBUS (the voltage of VBUS is 5V as an example) At this time, the input voltage of Vin + of the comparator is 5V, and the input voltage of Vin- is Vbat voltage or the divided voltage of VBUS. This voltage is less than the voltage of Vin +, so the Vout of the comparator will change from low level to High level, to control the base of the transistor to go high, make its collector and emitter conductive, VBUS and GND short-circuited, so that short-circuit protection is started, charging is stopped, and the purpose of protecting its charging interface and its internal circuit is achieved.

Scenario 2: The battery is dead (in this case, the complete dead battery is 0V). At this time, the Vin- of the comparator can only use the VBUS voltage division shown in Figure 6 and Figure 7. At this time, the charger is inserted and the Vin- The input voltage will become the divided voltage of VBUS (such as 4V), the Vout of the comparator is low, and the circuit does not work, which is equivalent to the working scenario with battery power. The above scenario 1 is similar.

Scenario 3: The shutdown circuit of the mobile phone does not work. Only when the charger is detected, the circuit starts to work. If no short circuit occurs, the comparator Vin + is greater than Vin-, and the output of the comparator is always low. When a short circuit occurs At this time, the work flow is the same as scenario 1, which is not repeated here.

It should be noted that, as long as a mobile terminal charged using a USB interface or a TPYE C-type interface or other non-standard interface can be charged, the technical solution of this embodiment can be adopted. In the technical solution of the embodiment of the present application, when the charging interface of the charging device is inserted or when charging, if the VBUS / VCHG pin and its adjacent signal pin are short-circuited or slightly short-circuited, the charging can be immediately turned off to protect the charging interface itself. , Can also protect the purpose of its related circuits, so as to achieve the purpose of protecting mobile terminals.

FIG. 9 is a schematic structural composition diagram of a charging device according to an embodiment of the present application. As shown in FIG. 9, the charging device includes a charging interface 900 and a comparison circuit 901 for comparing a voltage of a first pin 9001 of the charging interface 900. And a reference voltage that outputs a first control signal based on a comparison result; a switching circuit 902 is configured to control whether the second pin 9002 of the charging interface 900 is connected to ground based on the first control signal.

In one embodiment, the charging interface 900 includes N first pins 9001, where N is a positive integer; all N first pins 9001 of the charging interface 900 are connected to the first input terminal of the comparison circuit. The reference voltage is connected to a second input terminal of the comparison circuit, and the comparison circuit is configured to compare the voltages of the N first pins 9001 and the reference voltage respectively.

In an embodiment, if the voltage of at least one first pin 9001 among the N first pins 9001 is higher than the reference voltage, the output terminal of the comparison circuit 901 outputs the first voltage; If the voltages of the N first pins 9001 are lower than the reference voltage, the output terminal of the comparison circuit 901 outputs a second voltage; wherein the first voltage is higher than the second voltage.

In an embodiment, an output terminal of the comparison circuit 901 is connected to a control terminal of the switch circuit, and the conduction state of the switch circuit is controlled by the first control signal; wherein, if the first control signal With a first voltage, the switch circuit 902 is in a conducting state, and the second pin 9002 of the charging interface 900 is connected to ground; if the first control signal has a second voltage, the switch circuit 902 In the off state, the second pin 9002 of the charging interface 900 is not connected to the ground; wherein the first voltage is higher than the second voltage.

In one embodiment, the switching circuit 902 is a transistor or a MOS transistor.

In one embodiment, the reference voltage is less than the voltage of the second pin 9002.

In one embodiment, the device further includes: a voltage dividing circuit 903; a voltage of the second pin 9002 is connected to an input terminal of the voltage dividing circuit 903, and an output voltage of the voltage dividing circuit 903 is used as the voltage Reference voltage.

In one embodiment, the first pin 9001 is a signal pin, and the second pin 9002 is a charging pin.

The charging interface, the comparison circuit, the switching circuit, and the voltage dividing circuit in the charging device according to the embodiment of the present application can be understood with reference to the specific circuit structures shown in FIG. 2 to FIG. 7, and are not repeated here. The functions implemented by the charging device shown in FIG. 9 can be understood with reference to the related description of the protection method of the charging interface.

The technical solution of the embodiment of the present application is used to prevent micro-short circuit, short circuit caused by mobile terminal dust and water, and plugging or unplugging the charging interface or other types of charging terminals by the end user to short-circuit the VBUS / VCHG pin to the adjacent signal pin. As a result, the charging interface and related circuits on the circuit board are burned out, which protects the mobile terminal and improves the satisfaction of the end user.

The technical solutions described in the embodiments of the present application can be arbitrarily combined without conflict.

In the several embodiments provided in this application, it should be understood that the disclosed method and smart device may be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, such as multiple units or components may be combined, or Can be integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed components are coupled, or directly coupled, or communicated with each other through some interfaces. The indirect coupling or communication connection of the device or unit may be electrical, mechanical, or other forms. of.

The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, which may be located in one place or distributed to multiple network units; Some or all of the units may be selected according to actual needs to achieve the objective of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into a second processing unit, or each unit may be separately used as a unit, or two or more units may be integrated into a unit; The above integrated unit may be implemented in the form of hardware, or in the form of hardware plus software functional units.

The above is only a specific implementation of this application, but the scope of protection of this application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in this application. It should be covered by the protection scope of this application.

Claims

A method for protecting a charging interface, wherein the method includes:

Comparing the voltage of the first pin of the charging interface with the reference voltage, and obtaining a first control signal based on the comparison result;

Based on the first control signal, control whether the second pin of the charging interface is connected to ground.
The method according to claim 1, wherein the charging interface comprises N first pins, and N is a positive integer;

Comparing the voltage of the first pin of the charging interface with the reference voltage includes:

All N first pins of the charging interface are connected to a first input terminal of a comparison circuit, the reference voltage is connected to a second input terminal of the comparison circuit, and the N The voltage of the first pin and the reference voltage are compared respectively.
The method according to claim 2, wherein the outputting the first control signal based on the comparison result comprises:

If at least one of the N first pins has a voltage higher than the reference voltage, the output terminal of the comparison circuit outputs the first voltage;

If the voltages of the N first pins are lower than the reference voltage, an output terminal of the comparison circuit outputs a second voltage;

The first voltage is higher than the second voltage.
The method according to claim 2 or 3, wherein the controlling whether the second pin of the charging interface is connected to ground based on the first control signal comprises:

An output terminal of the comparison circuit is connected to a control terminal of the switching circuit, and the conducting state of the switching circuit is controlled by the first control signal;

If the first control signal has a first voltage, the switch circuit is in a conducting state, and a second pin of the charging interface is connected to ground;

If the first control signal has a second voltage, the switch circuit is in an off state, and the second pin of the charging interface is not connected to ground;

The first voltage is higher than the second voltage.
The method according to claim 4, wherein the switching circuit is a triode or a field effect MOS transistor.
The method according to claim 1, wherein the reference voltage is smaller than a voltage of the second pin.
A charging device, characterized in that the device includes: a charging interface;

A comparison circuit for comparing a voltage of a first pin of the charging interface with a reference voltage, and outputting a first control signal based on a comparison result;

A switch circuit is configured to control whether the second pin of the charging interface is connected to ground based on the first control signal.
The device according to claim 7, wherein the charging interface includes N first pins, and N is a positive integer;

The N first pins of the charging interface are connected to a first input terminal of the comparison circuit, and the reference voltage is connected to a second input terminal of the comparison circuit. The voltages of the first pins and the reference voltage are compared respectively.
The device according to claim 8, characterized in that:

If at least one of the N first pins has a voltage higher than the reference voltage, the output terminal of the comparison circuit outputs the first voltage;

If the voltages of the N first pins are lower than the reference voltage, an output terminal of the comparison circuit outputs a second voltage;

The first voltage is higher than the second voltage.
The device according to claim 8 or 9, wherein:

An output terminal of the comparison circuit is connected to a control terminal of the switching circuit, and the conduction state of the switching circuit is controlled by the first control signal; wherein,

If the first control signal has a first voltage, the switch circuit is in a conducting state, and a second pin of the charging interface is connected to ground;

If the first control signal has a second voltage, the switch circuit is in an off state, and the second pin of the charging interface is not connected to ground;

The first voltage is higher than the second voltage.
The device according to claim 10, wherein the switching circuit is a triode or a MOS transistor.
The device according to claim 7, wherein the reference voltage is smaller than a voltage of the second pin.
The device according to claim 12, further comprising: a voltage dividing circuit;

The voltage of the second pin is connected to the input terminal of the voltage dividing circuit, and the output voltage of the voltage dividing circuit is used as the reference voltage.
The device according to claim 7, wherein the first pin belongs to a signal pin, and the second pin is a charging pin.