JP2017201862A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus capable of preventing a burnout accident even in the case where an AC adaptor does not have a burnout prevention function when the AC adaptor conforming with USB Type-C standard is used.SOLUTION: Disclosed is an electronic apparatus including a USB Type-C standard receptacle. This electronic apparatus includes: a sense resistor which is provided in a short-circuit current generation path between a shell of the receptacle and the ground; a switch which is connected so as to be able to cut and energize a signal path corresponding to a CC pin of the receptacle; and a control circuit which detects a current flowing through a sense resistor and controls to cut off the switch when the current satisfies a predetermined condition.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic device including a receptacle of the USB Type-C standard.

  As an example of an electronic device in which a burnout accident occurs during charging, a smartphone can be given. For example, a USB connector or USB receptacle may burn out while charging a smartphone with an AC adapter. As a cause of burnout, half short-circuit due to adhesion of metal foreign matter or the like inside the connector or receptacle can be considered.

  On the other hand, as a countermeasure on the smartphone side, by providing a DC cut capacitor between the receptacle shell and the ground, the AC adapter shell is electrically floated to prevent a short circuit and reduce burnout accidents. It has been tried.

  In addition, as a countermeasure on the AC adapter side, a function to detect abnormal temperature, a function to detect overcurrent, etc. are provided, and the power supply is forcibly stopped when an abnormal temperature or overcurrent is detected to try to reduce burnout accidents. Has been. In addition to the above measures, measures have been taken such as physically separating the shell on the AC adapter side to electrically float it.

  In recent years, the USB Type-C standard has been established as the next generation standard for USB connectors and USB cables (Non-Patent Document 1). In the USB Type-C standard, power supply with a larger capacity than before is possible. For example, in the μUSB standard, the maximum current is 2 A, but in the USB Type-C standard, the maximum current is 5 A.

"USB Type-C", [online], April 15, 2016, [April 15, 2016 search], Internet <URL: https: //en.wikipedia.org/wiki/USB_Type-C>

  When a USB Type-C connector is used, there is a risk that the scale of the burnout accident will be larger than before as the maximum current increases. In order to prevent burnout accidents and ensure safety, it is necessary to take measures on both the smartphone side and the AC adapter side. For example, even when the above-described DC cut capacitor as a countermeasure on the smartphone side is used, the half short circuit cannot be prevented when the shell on the AC adapter side falls to the ground. In this case, the aforementioned burnout prevention function is required on the AC adapter side.

  However, recently, there are many AC adapters such as third-party AC adapters that do not have a burnout prevention function. For this reason, it is difficult to ensure safety with safety measures that depend on the function of the AC adapter.

  Accordingly, the present invention provides an electronic device that can prevent a burnout accident even when the AC adapter does not have a burnout prevention function when an AC adapter that conforms to the USB Type-C standard is used. Objective.

  The electronic device of the present invention is an electronic device including a receptacle of the USB Type-C standard, and includes a sense resistor, a switch, and a control circuit.

  The sense resistor is provided in a short-circuit current generation path between the receptacle shell and the ground. The switch is connected so that a signal path corresponding to the CC pin of the receptacle can be disconnected and conducted. The control circuit detects the current flowing through the sense resistor, and controls the switch to be disconnected when the detected current satisfies a predetermined condition.

  According to the electronic apparatus of the present invention, when an AC adapter that conforms to the USB Type-C standard is used, a burnout accident can be prevented even if the AC adapter does not have a burnout prevention function.

1 is a block diagram illustrating a circuit configuration of an electronic apparatus according to a first embodiment. FIG. 6 is a block diagram illustrating a circuit configuration of an electronic apparatus according to a second embodiment. FIG. 9 is a block diagram illustrating a circuit configuration of an electronic apparatus according to a third embodiment. FIG. 9 is a block diagram illustrating a circuit configuration of an electronic apparatus according to a fourth embodiment. The figure which illustrates the combination of the component requirements which can be implemented. FIG. 10 is a block diagram illustrating a circuit configuration of an electronic apparatus according to a fifth embodiment. FIG. 15 is a block diagram illustrating a configuration example of a general-purpose system or a computer device that can be used to realize the electronic apparatus of the invention.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, the same number is attached | subjected to the structure part which has the same function, and duplication description is abbreviate | omitted.

  Hereinafter, the electronic apparatus according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a circuit configuration of an electronic apparatus 1 according to the present embodiment. In the present specification, the term “electronic device” is a concept including general information devices, general household appliances, and general industrial electrical products due to the nature of the present invention. The electronic device in this specification may be any device provided with a receptacle of the USB Type-C standard.

As shown in FIG. 1, the electronic device 1 of the present embodiment includes a USB Type-C standard receptacle 10, a system circuit 11, a rechargeable battery 12, a pull-down resistor 13, a FET (Field effect transistor) switch 14, The configuration includes a control circuit 15 and a sense resistor 16. The receptacle 10 includes a lock plate 101, a shell 102, a V _BUS pin 103, and a CC (Configuration Channel) pin 104.

The electronic device 1 of the present embodiment naturally has other structural requirements than the structural requirements disclosed in FIG. 1, but regarding the structural requirements that are not related to the contents described in the present embodiment or have a weak relationship. The illustration and description will be omitted. For example, the receptacle 10 of the USB Type-C _{standard, V BUS} pin 103, besides CC pin 104, GND pin, SSTXp1 pin SSTXn1 pin, ... is provided with the pins, such as, the pins, the present embodiment The illustration is omitted because it is not related to the contents described in the examples.

  The receptacle 10 is connected to a mating connector that conforms to the USB Type-C standard. It is assumed that the counterpart connector is connected to a charging adapter conforming to the USB Type-C standard via a cable.

The V _BUS pin 103 of the receptacle 10 is connected to the system circuit 11, and power (for example, +5 V) is supplied to the system circuit 11 through this path, and the charging ground 12 is charged.

  The CC pin 104 of the receptacle 10 is connected to the pull-down resistor 13 and the FET switch 14. The FET switch 14 is connected so that the signal path corresponding to the CC pin 104 can be disconnected and conducted. It is preferable that the FET switch 14 be normally on. The CC pin 104 has a function of checking the connection between the electronic device 1 and an external device such as a charging adapter. Therefore, the charging adapter conforming to the USB Type-C standard has a specification in which power cannot be supplied to the electronic device 1 unless the connection confirmation by the CC pin conduction is made. This is one of the specifications of the USB Type-C standard (referred to as a cold socket), and the operation of each component will be described below on the premise of the function of the CC pin described above.

  It is assumed that the control circuit 15 is connected to both ends of the sense resistor 16 and can detect a current flowing through the sense resistor 16. The control circuit 15 is connected to the FET switch 14 and can control the FET switch 14 to be either connected or disconnected. The FET switch 14 is not limited to the FET type, and can be replaced with another type of switch (however, controllable by the control circuit 15).

  The sense resistor 16 is provided in a short-circuit current generation path between the shell 102 of the receptacle 10 and the ground. If a current is detected in sense resistor 16 (with a value greater than or equal to a meaningful value), this means that a short-circuit current has occurred between shell 102 and ground. In this case, in order to protect the electronic device 1 and the cable from burning, it is necessary to quickly stop the power supply from the charging adapter.

  Accordingly, the control circuit 15 controls the FET switch 14 to be disconnected when the current detected by the sense resistor 16 satisfies a predetermined condition (for example, when the detected current exceeds a predetermined threshold). When the FET switch 14 is disconnected, the signal path corresponding to the CC pin for confirming the connection between the electronic device 1 and the charging adapter is cut off, so that the charging adapter is disconnected from the electronic device 1. The power supply is stopped (the power supply of the charging adapter is controlled to be OFF). Thereby, burning of electronic equipment 1 or a cable can be prevented.

[Modification 1]
In the above-described first embodiment, the short-circuit current generated between the shell 102 and the ground is detected. However, the short-circuit current may be generated in another path. For example, a case where a short-circuit current occurs between the lock plate 101 and the ground can be considered (broken line in FIG. 1). In the electronic device according to the first modification, a configuration for protecting the electronic device 1 and the cable from burning when a short-circuit current occurs between the lock plate 101 and the ground will be described.

  There is only one difference between the present modification and the first embodiment. That is, the difference from the first embodiment is that the sense resistor 16 is provided in the short-circuit current generation path between the lock plate 101 and the ground. When the current detected by the sense resistor 16 satisfies a predetermined condition (for example, when the detected current exceeds a predetermined threshold value. In this case, a short-circuit current is generated between the lock plate 101 and the ground. This means that the FET switch 14 is cut off to protect the electronic device 1 and the cable from burning. By combining this modification and the first embodiment, for example, it is possible to detect a short-circuit current between the shell 102 and the ground and between the lock plate 101 and the ground. Most simply, one sense resistor 16 is provided for each path, and the current flowing through the two sense resistors in the control circuit 15 may be monitored simultaneously.

  Hereinafter, the electronic apparatus according to the second embodiment will be described with reference to FIG. FIG. 2 is a block diagram illustrating a circuit configuration of the electronic apparatus 2 according to the present embodiment. The difference between the present embodiment and the first embodiment is only one point. That is, the second embodiment is different from the first embodiment only in that a capacitor 27 is newly provided in the short-circuit current generation path between the shell 102 and the ground. The capacitor 27 is provided for the purpose of cutting DC (direct current component). By electrically separating the shell 102 from the ground (with a floating state) by the capacitor 27, half short-circuit due to the conductive foreign matter remaining inside the receptacle or the counterpart connector can be avoided to a certain extent, and it is safer. It becomes composition.

  According to the electronic device 2 of the present embodiment, in addition to the effects of the first embodiment, a double safety measure can be taken by separating the shell 102 from the ground.

[Modification 2]
The electronic device of Modification 2 is characterized in that the sense resistor 16 in the electronic device 2 of Embodiment 2 is provided in a short-circuit current generation path between the lock plate 101 and the ground. Therefore, the differences from the second embodiment are the same as the differences described in the first modification.

By the way, when there is no power supply from the outside of the electronic device 2 (electronic device 1), the control circuit 15 is driven (operated) by being supplied with power from the rechargeable battery 12. Hereinafter, consideration will be given to ensuring the operation of the control circuit 15 when the voltage V _BATT of the rechargeable battery 12 is low. For example, when the voltage V _BATT of the rechargeable battery 12 becomes equal to or lower than a predetermined system sleep reference voltage V _SLEEP (V _BATT ≦ V _SLEEP ) (typically, when the battery is out of charge or low battery), the system circuit 11 Control the system to sleep. In this case and when V _BATT is larger than the rechargeable battery protection circuit operating voltage V _PROTECT (V _PROTECT <V _BATT ), the lower limit value V _CTRL-MIN of the operating voltage of the control circuit 15 is previously set to V _SLEEP. The control circuit 15 may be designed to have a smaller voltage. If the control circuit 15 is designed as described _above, in a case _{where V BATT} is greater than _{V SLEEP} less and _{V PROTECT (V PROTECT <V BATT} ≦ V SLEEP), the control circuit 15 by the _{V BATT} is normally driven The Therefore, even in the low battery state, the control circuit 15 can continue to monitor the burnout of the connector.

On the other hand, when V _BATT ≦ V _PROTECT , the rechargeable battery protection circuit operates and the power supply path from the rechargeable battery 12 is shut off. In order to cut off the power supply path, an FET or the like that is turned off when it is detected that the voltage is lower than a certain voltage is mainly used. This is a measure for preventing overdischarge of the rechargeable battery 12. In this case, the control circuit 15 cannot receive power from the rechargeable battery 12 and cannot operate.

Therefore, when the electronic device 1 and the charging adapter are connected in a state where V _BATT is low enough that the rechargeable battery protection circuit operates, the control circuit 15 may not be able to temporarily monitor this. In Example 3 described below, an improvement was made to solve this problem.

  Hereinafter, the electronic apparatus according to the third embodiment will be described with reference to FIG. FIG. 3 is a block diagram illustrating a circuit configuration of the electronic apparatus 3 according to the present embodiment. There are two differences between the present embodiment and the first embodiment. That is, an auxiliary battery 38 for constantly driving the control circuit 15 is newly provided, and the sense resistor 16 is changed to a thermistor 39. Only differences from the first embodiment will be described below.

As described above, the auxiliary battery 38 is provided to stably operate the control circuit 15 even when the voltage V _BATT of the rechargeable battery 12 is low. With the auxiliary battery 38, the control circuit 15 can continue to monitor the short-circuit current even under the condition of V _BATT ≦ V _PROTECT , and can more reliably prevent burning of the electronic device 1 and the cable. The auxiliary battery 38 may be realized by a capacitor.

  The thermistor 39 has a configuration corresponding to the sense resistor 16 in the first and second embodiments. As a sign of the occurrence of a burnout accident, a short-circuit current as described above, or an abnormal temperature increase near the receptacle can be seen. Therefore, in this embodiment, a thermistor 39 is provided as an alternative to the sense resistor 16, and an abnormal temperature in the vicinity of the receptacle 10 is detected by the thermistor 39.

Specifically, the thermistor 39 is provided at a position where the temperature of the shell 102 of the receptacle 10 can be detected, and the control circuit 15 measures the resistance value R _THERM of the thermistor 39 and the resistance value R _{THERM satisfies a} predetermined condition. When filling, the FET switch 14 is controlled to be disconnected. For example, when the thermistor 39 is an NTC thermistor, the resistance value R _THERM gradually decreases as the temperature rises. In this case, the control circuit 15 controls the FET switch 14 to be disconnected when R _THERM is equal to or less than a predetermined threshold value τ ₁ . For example, when the thermistor 39 is a PTC thermistor, when a certain temperature is exceeded, the resistance value R _THERM increases rapidly as the temperature rises. In this case, the control circuit 15 controls the FET switch 14 to be disconnected when R _THERM exceeds a predetermined threshold value τ ₂ .

  According to the electronic apparatus 3 of the present embodiment, the control circuit 15 can be always operated by providing the auxiliary battery 38, and the same effect as that of the first embodiment can be achieved by using the thermistor 39.

[Modification 3]
There is only one difference between this modification and the third embodiment. That is, the third embodiment is different from the third embodiment only in that the thermistor 39 is provided at a position where the temperature of the lock plate 101 can be detected. The configuration of the third modification also has the same effect as that of the third embodiment.

  Hereinafter, an electronic apparatus according to the fourth embodiment will be described with reference to FIG. FIG. 4 is a block diagram showing a circuit configuration of the electronic device 4 of this embodiment. There is only one difference between the present embodiment and the third embodiment. That is, the third embodiment is different from the third embodiment only in that a capacitor 27 is newly provided in the short-circuit current generation path between the shell 102 and the ground. See Example 2 for capacitor 27.

  According to the electronic apparatus 4 of the present embodiment, in addition to the effects of the third embodiment, a double safety measure can be taken by separating the shell 102 from the ground.

[Modification 4]
There is only one difference between this modification and the fourth embodiment. That is, the difference from the fourth embodiment is that the thermistor 39 is provided at a position where the temperature of the lock plate 101 can be detected. The configuration of the modification 4 also has the same effect as that of the fourth embodiment.

  FIG. 5 exemplifies a combination of configuration requirements that can be implemented. As shown in FIG. 5, in addition to the combinations of the above-described embodiments, there are combinations of structural requirements that have the same effect. For example, the configuration including the thermistor 39 provided so that the temperature of the shell 102 can be detected and not including the auxiliary battery 38 and the DC cut capacitor 27 (second row center column in FIG. 5) is illustrated as an example and a modification. However, if the auxiliary battery 38 of Example 3 is omitted, the same configuration is obtained. The same applies to other combinations. Note that FIG. 5 is merely an example, and does not limit the combination of the configuration requirements of the present invention.

  Hereinafter, the electronic apparatus of Example 5 will be described with reference to FIG. FIG. 6 is a block diagram showing a circuit configuration of the electronic device 5 of this embodiment. In the present embodiment, a configuration that has the same effects as those of the above-described embodiment is disclosed with a simpler configuration than the electronic devices 1 to 4 of the above-described Embodiments 1 to 4. Specifically, the electronic device 5 of this embodiment includes a switch 54 between the pull-down resistor 13 and the ground. The switch 54 is an element that cuts a signal path corresponding to the CC pin when exposed to a temperature equal to or higher than a predetermined temperature. The switch 54 can be realized by, for example, a PTC, a temperature fuse, a bimetal switch, or the like. According to the configuration of the electronic device 5 of the fifth embodiment, when the switch 54 is exposed to an abnormal temperature, the switch 54 is cut off, and a signal path corresponding to the CC pin for confirming the connection between the electronic device 5 and the charging adapter is provided. Since it will be interrupted | blocked, there exists an effect equivalent to the electronic devices 1-4 of Examples 1-4. According to the configuration of the present embodiment, the control circuit 15 and the auxiliary power supply 38 described above can be omitted. In addition, as shown in FIG. 6, it is good also as a structure provided with the above-mentioned DC cut capacitor 27. FIG.

<Supplementary note>
The device of the present invention can communicate with an input unit 11000 to which a keyboard or the like can be connected, an output unit 12000 to which a liquid crystal display or the like can be connected, and a hardware entity as a single hardware entity as shown in FIG. A communication unit 13000 to which various communication devices (for example, communication cables) can be connected, a CPU 14000 (which may include a central processing unit, a cache memory or a register), a RAM 15000 or ROM 16000 as a memory, an external storage device 17000 as a hard disk, The input unit 11000, the output unit 12000, the communication unit 13000, the CPU 14000, the RAM 15000, the ROM 16000, and the bus 18000 are connected so that data can be exchanged between the external storage devices 17000. If necessary, the hardware entity may be provided with a device (drive) 19000 that can read and write a recording medium such as a CD-ROM. A physical entity having such hardware resources includes a general-purpose computer.

  The external storage device of the hardware entity stores a program necessary for realizing the above functions and data necessary for processing the program (not limited to the external storage device, for example, reading a program) It may be stored in a ROM that is a dedicated storage device). Data obtained by the processing of these programs is appropriately stored in a RAM or an external storage device.

  In the hardware entity, each program stored in an external storage device (or ROM or the like) and data necessary for processing each program are read into a memory as necessary, and are interpreted and executed by a CPU as appropriate. .

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention. In addition, the processing described in the above embodiment may be executed not only in time series according to the order of description but also in parallel or individually as required by the processing capability of the apparatus that executes the processing. .

  As described above, when the processing functions in the hardware entity (the apparatus of the present invention) described in the above embodiments are realized by a computer, the processing contents of the functions that the hardware entity should have are described by a program. Then, by executing this program on a computer, the processing functions in the hardware entity are realized on the computer.

  The program describing the processing contents can be recorded on a computer-readable recording medium. As the computer-readable recording medium, for example, any recording medium such as a magnetic recording device, an optical disk, a magneto-optical recording medium, and a semiconductor memory may be used. Specifically, for example, as a magnetic recording device, a hard disk device, a flexible disk, a magnetic tape or the like, and as an optical disk, a DVD (Digital Versatile Disc), a DVD-RAM (Random Access Memory), a CD-ROM (Compact Disc Read Only). Memory), CD-R (Recordable) / RW (ReWritable), etc., magneto-optical recording medium, MO (Magneto-Optical disc), etc., semiconductor memory, EEP-ROM (Electronically Erasable and Programmable-Read Only Memory), etc. Can be used.

  The program is distributed by selling, transferring, or lending a portable recording medium such as a DVD or CD-ROM in which the program is recorded. Furthermore, the program may be distributed by storing the program in a storage device of the server computer and transferring the program from the server computer to another computer via a network.

  A computer that executes such a program first stores, for example, a program recorded on a portable recording medium or a program transferred from a server computer in its own storage device. When executing the process, the computer reads a program stored in its own recording medium and executes a process according to the read program. As another execution form of the program, the computer may directly read the program from a portable recording medium and execute processing according to the program, and the program is transferred from the server computer to the computer. Each time, the processing according to the received program may be executed sequentially. Also, the program is not transferred from the server computer to the computer, and the above-described processing is executed by a so-called ASP (Application Service Provider) type service that realizes the processing function only by the execution instruction and result acquisition. It is good. Note that the program in this embodiment includes information that is used for processing by an electronic computer and that conforms to the program (data that is not a direct command to the computer but has a property that defines the processing of the computer).

  In this embodiment, a hardware entity is configured by executing a predetermined program on a computer. However, at least a part of these processing contents may be realized by hardware.

Claims (7)

An electronic device including a USB Type-C standard receptacle,
A sense resistor provided in a short-circuit current generation path between the receptacle shell and ground;
A switch connected to be able to disconnect and conduct a signal path corresponding to the CC pin of the receptacle;
A control circuit that detects a current flowing through the sense resistor and controls the switch to be disconnected when the current satisfies a predetermined condition;
Including electronic equipment. An electronic device including a USB Type-C standard receptacle,
A thermistor provided to detect the temperature of the receptacle shell;
A switch connected to be able to disconnect and conduct a signal path corresponding to the CC pin of the receptacle;
A control circuit for measuring the resistance value of the thermistor and controlling the switch to be disconnected when the resistance value satisfies a predetermined condition;
Including electronic equipment. An electronic device including a USB Type-C standard receptacle,
A sense resistor provided in a short-circuit current generation path between the receptacle lock plate and ground;
A switch connected to be able to disconnect and conduct a signal path corresponding to the CC pin of the receptacle;
A control circuit that detects a current flowing through the sense resistor and controls the switch to be disconnected when the current satisfies a predetermined condition;
Including electronic equipment. An electronic device including a USB Type-C standard receptacle,
A thermistor provided so as to be able to detect the temperature of the lock plate of the receptacle;
A switch connected to be able to disconnect and conduct a signal path corresponding to the CC pin of the receptacle;
A control circuit for measuring the resistance value of the thermistor and controlling the switch to be disconnected when the resistance value satisfies a predetermined condition;
Including electronic equipment. An electronic device according to any one of claims 1 to 4,
The control circuit comprises:
An electronic device that operates at a voltage equal to or lower than a preset system sleep reference voltage in the electronic device. An electronic device according to any one of claims 1 to 5,
An electronic device provided with an auxiliary battery that supplies power to the control circuit when power supply from the rechargeable battery of the electronic device to the control circuit is interrupted. An electronic device including a USB Type-C standard receptacle,
An electronic device including a switch that disconnects a signal path corresponding to a CC pin of the receptacle when exposed to a temperature equal to or higher than a predetermined temperature.

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