CN106655316B

CN106655316B - Charging circuit and terminal device

Info

Publication number: CN106655316B
Application number: CN201610840043.XA
Authority: CN
Inventors: 张哲�
Original assignee: Qiku Internet Technology Shenzhen Co Ltd
Current assignee: Qiku Internet Technology Shenzhen Co Ltd
Priority date: 2016-09-21
Filing date: 2016-09-21
Publication date: 2020-05-12
Anticipated expiration: 2036-09-21
Also published as: CN106655316A

Abstract

The invention discloses a charging circuit and terminal equipment, wherein the charging circuit comprises two signal pins, two power supply pins, a USB controller and a power supply module, the two power supply pins are electrically connected with the power supply module, the charging circuit also comprises a first switch, and the two signal pins are switched between two states of mutually short-circuit and electrically connected with the USB controller through the first switch. According to the charging circuit provided by the embodiment of the invention, the first switch is arranged between the signal pins and the USB controller, so that the two signal pins can be switched between two states of mutual short circuit and electric connection with the USB controller through the first switch, the switching of the USB interface between the SDP type and the DCP type is realized, when the DCP type is switched, the external charging can be carried out by using large current, the charging speed is improved, and the technical problem of slow charging speed when the terminal equipment is externally charged is solved.

Description

Charging circuit and terminal device

Technical Field

The present invention relates to the field of electronic technologies, and in particular, to a charging circuit and a terminal device.

Background

Universal Serial Bus (USB) has become a standard application for powering portable devices as well as its Serial communication capabilities. Today, USB power has expanded to battery charging, ac adapters, and other forms of power applications. One significant effect of the popularity of the application is that the charging and powering of portable devices can interchange plugs and adapters. Thus, the present solution allows for charging using multiple power sources, as compared to previous architectures where each device used a dedicated adapter.

Taking USB2.0 as an example, the USB2.0mini interface has 5 PINs (PINs), including:

a pair of power supply pins: VBUS/GND

A pair of signal pins: d +/D-

A master-slave identification pin: UID (user identifier)

Two USB interface devices need to be connected through a USB data line supporting OTG (On-The-Go). The UID of only one end of the data line is valid, and if the valid end of the UID is connected with the equipment A, the equipment A is indicated as a host; the corresponding device B at the other end is a slave. When the master and the slave are determined, the host outputs a voltage signal which accords with the USB specification through VBUS (positive pole); after the slave is activated by the VBUS voltage signal, the type of the interface of the host can be detected according to the USB related protocol (BC 1.2).

There are mainly 4 types of host interfaces (sometimes subdivided) namely "SDP/DCP/CDP/other". The sdp (standard downlink port) is a USB standard downlink port, which is a commonly-called "USB data interface", and the dcp (dedicated Charging port) is a dedicated Charging port, which is a commonly-called "standard charger interface". In the SDP interface (such as a USB interface of a PC), a USB controller is connected with D +/D-for data receiving and transmitting; in the DCP interface (namely a standard charger), D +/D-is short-circuited and is only used for identifying the interface type.

The slave can detect which type the interface of the master belongs to through the handshake protocol specified by BC 1.2. If the master is an SDP device, the slave can only draw up to 500mA of current according to the USB specification. Whereas if the master is a DCP device, the slave is allowed to draw at least 1.8A of current.

At present, most mobile terminals (such as smart phones) adopt USB interfaces as channels for power supply and data input and output, and comply with USB related protocol specifications. As shown in fig. 1, when the mobile terminal is used as an OTG master to charge the slave, the mobile terminal first identifies the identity of the slave through the single-ended UID signal of the USB data line, and then outputs a 5V voltage from VBUS to the slave through a Power Management Integrated Circuit (PMIC); after the slave machine receives the VBUS signal, the D +/D-state is detected to judge the type of the host machine interface, the D +/D-state of the mobile terminal is connected to the USB controller for data transmission, therefore, the slave machine can be judged as the SDP equipment, the slave machine can actively limit the self absorption current, and the current is absorbed from the VBUS according to the specification of at most 500 mA. That is, even though the OTG host has a strong load capacity, it cannot provide a larger charging current. However, in the current situation where the battery capacity has generally exceeded 3000mAh, the 500mA current specification charges extremely slowly with little practical value.

In summary, when the conventional terminal device is charged externally, the charging current is small, and the charging speed is very slow.

Disclosure of Invention

The invention mainly aims to provide a charging circuit and a terminal device, and aims to solve the technical problems of small charging current and slow charging speed when the terminal device is externally charged.

In order to achieve the above object, the present invention provides a charging circuit, which includes two signal pins, two power pins, a USB controller, a power module, and a first switch, wherein the two power pins are electrically connected to the power module, and the two signal pins are switched between a short circuit state and an electrical connection state with the USB controller through the first switch.

Furthermore, the power supply module also comprises a second switch, and at least one of the two power supply pins is electrically connected with the power supply module through the second switch.

The second control module is electrically connected with the second switch and is used for controlling the second switch to be switched on and off.

Further, the power supply pin comprises a VBUS pin, and the second switch is connected between the VBUS pin and the power supply module in series.

Further, the second switch is a single pole, single throw switch.

The first control module is electrically connected with the first switch and is used for controlling the switching operation of the first switch.

Further, the first switch is a double-pole double-throw switch.

Further, the two signal pins comprise a positive pin and a negative pin.

Further, the power module includes a battery and a power management integrated circuit PMIC electrically connected to each other, and the PMIC is electrically connected to the two power pins.

The invention also provides terminal equipment which comprises a charging circuit, wherein the charging circuit comprises two signal pins, two power supply pins, a USB controller, a power supply module and a first switch, the two power supply pins are electrically connected with the power supply module, and the two signal pins are switched between two states of mutually short-circuit and electrically connecting with the USB controller through the first switch.

According to the charging circuit provided by the embodiment of the invention, the first switch is arranged between the signal pins and the USB controller, so that the two signal pins can be switched between two states of mutual short circuit and electric connection with the USB controller through the first switch, the switching of the USB interface between the SDP type and the DCP type is realized, when the DCP type is switched, the external charging can be carried out by using large current, the charging speed is improved, and the technical problem of slow charging speed when the terminal equipment is externally charged is solved. Meanwhile, when the DCP type is switched, the two signal pins are disconnected with the USB controller, so that the USB data connection is physically disconnected, and only a charging function is provided, so that the safety is improved.

Drawings

FIG. 1 is a schematic circuit diagram illustrating a connection between a mobile terminal as a master and a slave in the prior art;

FIG. 2 is a circuit diagram of a charging circuit according to a first embodiment of the present invention;

FIG. 3 is a circuit diagram of a charging circuit according to a second embodiment of the present invention;

FIG. 4 is a circuit diagram of a charging circuit according to a third embodiment of the present invention;

FIG. 5 is a circuit diagram of a charging circuit according to a fourth embodiment of the present invention;

fig. 6 is a circuit connection diagram illustrating a mobile terminal to which the charging circuit according to the embodiment of the present invention is applied, as a host, connected to a slave.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative only and should not be construed as limiting the invention.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or wirelessly coupled. As used herein, the term "and/or" includes all or any element and all combinations of one or more of the associated listed items.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As will be appreciated by those skilled in the art, "terminal" as used herein includes both devices that are wireless signal receivers, devices that have only wireless signal receivers without transmit capability, and devices that include receive and transmit hardware, devices that have receive and transmit hardware capable of performing two-way communication over a two-way communication link. Such a device may include: a cellular or other communication device having a single line display or a multi-line display or a cellular or other communication device without a multi-line display; PCS (Personal Communications Service), which may combine voice, data processing, facsimile and/or data communication capabilities; a PDA (Personal Digital Assistant), which may include a radio frequency receiver, a pager, internet/intranet access, a web browser, a notepad, a calendar and/or a GPS (Global Positioning System) receiver; a conventional laptop and/or palmtop computer or other device having and/or including a radio frequency receiver. As used herein, a "terminal" or "terminal device" may be portable, transportable, installed in a vehicle (aeronautical, maritime, and/or land-based), or situated and/or configured to operate locally and/or in a distributed fashion at any other location(s) on earth and/or in space. As used herein, a "terminal Device" may also be a communication terminal, a web terminal, a music/video playing terminal, such as a PDA, an MID (Mobile Internet Device) and/or a Mobile phone with music/video playing function, or a smart tv, a set-top box, etc.

Example one

Referring to fig. 2, a charging circuit according to a first embodiment of the present invention is provided, which includes two signal pins, two power pins, a USB controller, a power module, and a first switch S1. The two power pins are electrically connected with the power module, and the two signal pins are switched between two states of being mutually short-circuited and electrically connected with the USB controller through the first switch S1.

In the embodiment of the invention, the two signal pins are a pair of differential signal pins of the USB interface and comprise a positive electrode pin (D +) and a negative electrode pin (D-). In other embodiments, the signal pins may be of other types, and are not limited herein.

In the embodiment of the invention, the two power supply pins are a positive electrode pin (VBUS) and a negative electrode (grounding) pin (GND) of the USB interface. In other embodiments, other types of power pins are also possible, and are not limited herein.

In an embodiment of the invention, the power module includes a PMIC and a battery, the battery is electrically connected to the PMIC, and the PMIC is electrically connected to the two power pins. Optionally, the power module may also add other electronic components on the basis of the present embodiment, or replace the PMIC with other electronic components. Alternatively, the power module may include only a battery.

In the embodiment of the present invention, the first switch S1 can be switched between two positions. When the first switch S1 is switched to position 1, the two signal pins are electrically connected to the USB controller, and the USB interface is of SDP type, and outputs a small current (e.g., at most 500mA) to the outside, which is mainly used for transmitting data. When the first switch S1 is switched to position 2, the two signal pins are shorted with each other, and at this time, the USB interface is simulated as a DCP type, and outputs a large current (for example, at least 1.8A) to the outside, which is mainly used for charging the outside. Optionally, in the default state, the first switch S1 is located at position 1, and is connected to the USB controller, i.e. the USB interface defaults to the SDP type. Thus, by switching the first switch S1, switching between the SDP and DCP types of the USB interface is achieved.

Optionally, the first switch S1 is a double-pole double-throw switch, or two single-pole single-throw switches, or other types of switches, which are not limited herein.

According to the charging circuit provided by the embodiment of the invention, the first switch S1 is arranged between the signal pins and the USB controller, so that the two signal pins can be switched between two states of mutual short circuit and electric connection with the USB controller through the first switch S1, the switching of the USB interface between the SDP type and the DCP type is realized, when the DCP type is switched, the charging circuit can be charged externally with large current, the charging speed is improved, and the technical problem of slow charging speed when terminal equipment is charged externally is solved. Meanwhile, when the DCP type is switched, the two signal pins are disconnected with the USB controller, so that the USB data connection is physically disconnected, and only a charging function is provided, so that the safety is improved.

Example two

Referring to fig. 3, a charging circuit according to a second embodiment of the present invention is provided, in which a first control module is added on the basis of the first embodiment, and the first control module is electrically connected to the first switch S1 for controlling the switching operation of the first switch S1. Alternatively, the first control module can also be integrated into other electronic components of the terminal device.

In the first embodiment, the user is required to manually switch the first switch S1, and in the present embodiment, the first control module automatically switches the first switch S1 when receiving a switching instruction or determining that a switching condition is satisfied. Therefore, the intelligent level is improved, and the user experience is improved.

EXAMPLE III

Referring to fig. 4, a charging circuit according to a third embodiment of the present invention is provided, in which a second switch S2 is added on the basis of the first embodiment, and at least one of the two power pins is electrically connected to the power module through the second switch S2.

In the embodiment of the invention, the second switch S2 is serially connected between the positive terminal (e.g., VBUS) of the power pin and the power module, i.e., the positive terminal of the power pin is electrically connected to the power module through the second switch S2. Optionally, the negative terminal of the power pin may be electrically connected to the power module through the second switch S2, or both the power pins may be electrically connected to the power module through the second switch S2.

In the first and second embodiments, after the USB data line is plugged, and the USB interface type needs to be switched during the charging process, the USB data line needs to be plugged again, because only after the USB data line is disconnected and the USB data line is plugged again, the slave is reactivated by the voltage of the power pin, the detection process for the interface type of the host is started, and then the current of the corresponding specification is absorbed according to the detected type.

In this embodiment, when the USB interface type needs to be switched, the second switch S2 is turned off first, and when the slave detects that the power pin signal is invalid, the slave stops absorbing current; then switching a first switch S1 (e.g., from position 1 to position 2 or from position 2 to position 1) to effect switching of the USB interface type (from SDP type to DCP type or from DCP type to SDP type); and finally, closing the second switch S2, reactivating the slave by the voltage of the power pin at the moment, starting a new detection process to detect the type of the USB interface of the host when detecting that the signal of the power pin is effective, and absorbing the current with the corresponding specification according to the detected type. Optionally, the second switch S2 is in a closed state by default.

Therefore, when the USB interface types are switched in the charging process, the data lines do not need to be plugged again, and only the second switch S2 needs to be disconnected and closed again, so that the complex flow that the user plugs the USB data lines again is omitted, and the switching is more convenient and quicker.

Example four

Referring to fig. 5, a charging circuit according to a fourth embodiment of the present invention is provided, and this embodiment adds a first control module and a second control module to the third embodiment. The first control module is electrically connected to the first switch S1 for controlling the switching operation of the first switch S1, and the second control module is electrically connected to the second switch S2 for controlling the on/off of the second switch S2. Optionally, the first control module and/or the second control module may also be integrated in other electronic components of the terminal device.

In the third embodiment, the user is required to manually switch the first switch S1 and the second switch S2. In this embodiment, when the second control module receives the switching instruction or determines that the switching condition is satisfied, the second control module automatically switches the first switch S1, that is, opens or closes the second switch S2; the first control module automatically switches the first switch S1 when receiving the switching instruction or when determining that the switching condition is satisfied. Therefore, the intelligent level is improved, and the user experience is improved.

The charging circuit of the embodiment of the invention is mainly applied to terminal equipment, in particular to the terminal equipment with a USB interface. The terminal device may be a mobile terminal such as a mobile phone and a tablet, a computer terminal such as a Personal Computer (PC) and a notebook computer, or other electronic devices.

As shown in fig. 6, which is an example of applying the charging circuit of the embodiment of the present invention to a mobile terminal, the mobile terminal in fig. 6 is connected to a slave as an OTG master. The host computer is provided with a USB interface, the USB interface comprises a pair of power supply pins VBUS and GND, and a pair of signal pins D + and D-, and the USB interface is connected with the slave computer through a USB data line. The host further includes a first switch S1, a second switch S2, a USB controller, a PMIC, a battery, and a Central Processing Unit (CPU), wherein the USB controller is electrically connected to the CPU, and the PMIC is electrically connected to the battery and the CPU, respectively. The VBUS pin is electrically connected to the PMIC through the second switch S2, the signal pins D + and D-are connected to the first switch S1, and the first switch S1 can be switched between position 1 and position 2. Typically, the first switch S1 is at position 1 in the default state, such that the signal pins D + and D-are electrically connected to the USB controller through the first switch S1, and the second switch S2 is closed in the default state, i.e., the host is an SDP device in the default state; when the first switch S1 is in position 2, signal pins D + and D-will be shorted at the back end, where the host is a DCP device. Wherein, the CPU can replace the functions of the first control module and the second control module (such as integrating the first control module and the second control module into the CPU) to control the switching of the first switch S1 and the second switch S2.

When the mobile terminal is used as an OTG host to charge the slave, the mobile terminal firstly identifies the host identity through a single-ended UID signal of a USB data line, and then outputs 5V voltage to the slave from VBUS through PMIC; after the slave machine receives the VBUS signal, the type of the host machine interface is judged by detecting the D +/D-state. When the first switch S1 is in position 1 and connected with the USB controller, the slave machine identifies the host machine as an SDP device, charges with small current (such as 500mA) and keeps USB data connection; when the first switch S1 is in position 2, such that the signal pins D + and D-are shorted at the back end, the slave recognizes the master as a DCP device and charges with a large current (e.g., 1.8A).

Assuming that the charging is currently performed with a small current, when the master receives a switching command, the second switch S2 is first turned off, and when the slave detects that the VBUS signal is invalid, the slave stops absorbing current and terminates the USB data connection; then the host switches a first switch S1 to make D +/D-in short circuit state, and simulates the USB interface as DCP type; finally, the master closes the second switch S2 (if necessary, the PMIC may increase the output power in advance to avoid being unable to load a larger current), and at this time, the slave detects that the VBUS signal is valid, starts a new detection process, and charges with a large current after detecting that the interface of the master is of the DCP type.

Assuming that the charging is currently performed with a large current, when the master receives a switching command, the second switch S2 is first turned off, and the slave detects that the VBUS signal is invalid and stops absorbing current; then the host switches a first switch S1 to connect D +/D-with the USB controller, simulating as SDP type; and finally, the master closes the second switch S2, the slave detects that the VBUS signal is valid at the moment, a new detection process is started, and when the interface of the master is detected to be the SDP type, the slave is charged by low current and the USB data connection is kept.

After the charging circuit provided by the embodiment of the invention is adopted, the mobile terminal can be simulated into a DCP type, so that a slave machine connected with the mobile terminal can absorb large current for charging, the technical problems of small charging current and extremely slow charging speed when the terminal equipment is charged externally are solved, and the charging speed of external charging is greatly improved. When only data needs to be transmitted externally, the mobile terminal can be switched back to the SDP type, so that the mobile terminal can be flexibly switched between the SDP type and the DCP type according to needs, various functions of the mobile terminal are met, and user experience is improved. Meanwhile, when the DCP type is switched, because the two signal pins are disconnected with the USB controller, the USB data connection of the mobile terminal is physically disconnected, and only a charging function is provided at the moment, so that the safety is improved.

The invention also provides a terminal device, which can be a mobile terminal such as a mobile phone and a tablet, a computer terminal such as a Personal Computer (PC) and a notebook computer, and other electronic devices. The terminal equipment comprises a charging circuit, wherein the charging circuit comprises two signal pins, two power pins, a USB controller, a power module and a first switch, the two power pins are electrically connected with the power module, and the two signal pins are switched between two states of mutually short-circuited and electrically connected with the USB controller through the first switch. The charging circuit described in this embodiment is the charging circuit according to the above embodiment of the present invention, and is not described herein again.

According to the terminal device provided by the embodiment of the invention, the first switch S1 is arranged between the signal pins and the USB controller, so that the two signal pins can be switched between two states of mutual short circuit and electric connection with the USB controller through the first switch S1, the switching of the USB interface between the SDP type and the DCP type is realized, when the USB interface is switched to the DCP type, a slave connected with the terminal device can absorb large current to charge, the technical problems that when the terminal device is externally charged, the charging current is small and the charging speed is extremely slow are solved, and the charging speed of external charging is greatly improved. When only data needs to be transmitted externally, the terminal equipment can be switched back to the SDP type, so that the terminal equipment can be flexibly switched between the SDP type and the DCP type according to needs, various functions of the mobile terminal are met, and user experience is improved.

Meanwhile, when the DCP type is switched, because the two signal pins are disconnected with the USB controller, the USB data connection of the terminal equipment is physically disconnected, and only a charging function is provided at the moment, so that the safety is improved.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, and are not to be construed as limiting the scope of the invention. Those skilled in the art can implement the invention in various modifications, such as features from one embodiment can be used in another embodiment to yield yet a further embodiment, without departing from the scope and spirit of the invention. Any modification, equivalent replacement and improvement made within the technical idea of using the present invention should be within the scope of the right of the present invention.

Claims

1. A charging circuit comprises two signal pins, two power supply pins, a USB controller and a power supply module, wherein the two power supply pins are electrically connected with the power supply module;

the first control module is electrically connected with the first switch and is used for controlling the switching operation of the first switch;

the power supply module also comprises a second switch, and at least one of the two power supply pins is electrically connected with the power supply module through the second switch;

the second control module is electrically connected with the second switch and is used for controlling the second switch to be switched on and off;

when the USB interface type needs to be switched, the second switch is disconnected, and the slave machine stops absorbing current when detecting that the power pin signal is invalid; then switching the first switch to realize the switching of the USB interface type; finally, the second switch is closed, the slave is reactivated by the voltage of the power supply pin at the moment, the signal of the power supply pin is detected to be effective, a new detection process is started to detect the type of the USB interface of the host, and the current with the corresponding specification is absorbed according to the detected type;

the power supply pin comprises a VBUS pin, and the second switch is connected between the VBUS pin and the power supply module in series;

the two signal pins comprise a positive electrode pin and a negative electrode pin;

when the current is being charged with a small current and a switching instruction is received, the second switch is disconnected firstly, and when the VBUS signal is detected to be invalid, the current absorption is stopped, and the USB data connection is terminated; then switching a first switch to enable the positive electrode pin and the negative electrode pin to be in a short circuit state, and simulating the USB interface into a DCP type; finally, a second switch is closed, the VBUS signal is detected to be effective at the moment, a new detection process is started, and after the interface of the host is detected to be a DCP type, the host is charged by large current;

when the current is charged with large current and a switching instruction is received, the second switch is disconnected firstly, and the VBUS signal is detected to be invalid at the moment, so that the current absorption is stopped; then switching a first switch to enable the positive electrode pin and the negative electrode pin to be connected with the USB controller and simulate the type of SDP; and finally, closing the second switch, detecting that the VBUS signal is valid at the moment, starting a new detection process, and charging with low current and keeping USB data connection when detecting that the interface of the host is the SDP type.

2. The charging circuit of claim 1, wherein the second switch is a single pole, single throw switch.

3. The charging circuit of claim 1 or 2, wherein the first switch is a double pole double throw switch.

4. The charging circuit of claim 1 or 2, wherein the power module comprises a battery and a Power Management Integrated Circuit (PMIC) electrically connected to each other, the PMIC being electrically connected to the two power pins.

5. A terminal device, characterized in that it comprises a charging circuit according to any one of claims 1 to 4.