JP2010146062A - Power source device, and method for controlling same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress standby power when an USB apparatus is not connected, and make restoration when the USB apparatus is connected. <P>SOLUTION: A microcomputer performs connection setting. When a hub control IC detects the existence of connection of the USB apparatus, communication data indicating the existence of the connection is transmitted from the hub control IC to the microcomputer. In S7, authentication processing is performed and normal processing is performed in response to an authentication result. In S9, when a certain time period for the absence of connection of the USB apparatus elapses, the non-connection is determined concerning the USB apparatus. In S10, the microcomputer becomes a sleep mode, so as to suppress the standby power. When the USB apparatus is connected to a USB port, an interruption is made. In S12, the state is restored from the sleep state into a normal operation state. When the normal operation state is restored, the processing is returned to S4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power supply device capable of outputting a stable DC power supply to a plurality of USB (Universal Serial Bus) ports and a control method for the power supply device.

  Conventionally, it is known to supply power to a USB device connected to a USB port through a USB port. For example, as shown in FIG. 1A, AC power is supplied to an AC / DC converter (hereinafter referred to as AC adapter) 2 through an AC (AC) power plug 1. The AC / DC converter 2 includes a plurality of USB ports 3a, 3b, 3c. A USB device (also referred to as a device) 5 is connected to the USB ports 3a, 3b, and 3c via a USB plug 4a, a USB cable 4b, and a USB plug 4c (sometimes not used). The DC power generated by the AC adapter 2 is supplied to the USB device 5.

  As shown in FIG. 1B, a charging device 6 having a secondary battery charged by a DC power output of an AC / DC converter is described in, for example, Patent Document 1 below. In the charging device (AC / DC converter and secondary battery) 6, the power of the secondary battery is output through the USB ports 3a, 3b, and 3c.

JP 2008-295129 A

  Further, the power supply of the peripheral device is turned on using the voltage change appearing on the power line of the USB terminal when the personal computer is turned on. Then, the power supply to the peripheral device is turned off using the voltage change appearing on the power line of the USB terminal when the personal computer is turned off. Thus, it is described in Patent Document 2 below to ensure the power ON / OFF of peripheral devices.

JP 2000-339072 A

  The conventional AC adapter 2 or the charging device 6 does not perform USB communication when supplying DC power to the USB device 5 through the USB ports 3a, 3b, and 3c. Therefore, power consumption in a state where no USB device is connected is extremely small. Even the one described in Patent Document 2 does not communicate with a USB device connected to a USB port even if it detects the voltage change of the power line of the USB port and controls the power ON / OFF of the peripheral device. There wasn't.

  However, among peripheral devices connected to the main body, such as personal computers and game machines, there are devices that are required to be authenticated by the main body. For example, in order to charge a secondary battery built in a peripheral device, if the AC adapter 2 or the charging device 6 that supplies DC power to the peripheral device is not a regular product, there is a possibility that normal DC power output will not be performed. is there. Therefore, when the authentication is established between the AC adapter 2 or the charging device 6 and the USB device, the DC power can be supplied.

  As shown in FIG. 2, in the case of an AC adapter having a plurality of, for example, two USB ports 3 a and 3 b, a USB hub control IC 12 is connected to the USB host control microcomputer 11. In the case of USB, two power lines (denoted as + and-in the figure) and two data lines (denoted as D + and D- in the figure) are used, and the USB port and USB plug are Two power terminals and two data terminals are provided. The USB host control microcomputer 11 is a microcomputer having a USB host function, and has one USB port. Therefore, the USB hub control IC 12 is used to branch USB communication to the USB ports 3a and 3b.

  In order to suppress power consumption of the AC adapter 2 or the charging device 6, it is desirable to suppress standby power (standby power) to which no USB device is connected. In a personal computer, a portable digital audio player, and the like, standby power of a built-in control microcomputer and a USB hub control IC is not large compared to the overall standby power. Therefore, the necessity for suppressing standby power related to USB is small. However, in the case of an AC adapter or a charging device that supplies power to a USB device, the proportion of power consumption related to USB is large in the total standby power.

  If there is only one USB port, the USB port is directly connected to the USB host control microcomputer. In that case, the USB host control microcomputer can determine whether or not a USB device is connected to the USB port. The microcomputer can enter the sleep state by determining that the USB device is not connected.

  As shown in FIG. 2, when the USB hub control IC 12 is interposed between the microcomputer 11 and the USB ports 3a and 3b, the microcomputer 11 determines that no USB device is connected to the USB ports 3a and 3b. Can not. As a result, there is a problem that communication continues between the microcomputer 11 and the USB hub control IC 12 even when the USB device is not connected, and standby power is not reduced.

  A second problem is that the return operation is not performed when the USB device is not connected to the connected device. The USB hub control IC 12 can detect that the USB device is not connected. If the USB host control microcomputer 11 knows that the USB device is not connected by communication with the USB hub control IC 12, the communication is stopped and the sleep state is entered. When the microcomputer 11 stops communication, the USB hub control IC 12 enters a sleep state. In this way, standby power can be reduced.

  Since both the microcomputer 11 and the USB hub control IC 12 are in the sleep state, the connection setting up to that point is cancelled. Therefore, when a USB port device is connected to any one of the USB ports, the USB hub control IC is disconnected from the USB host control microcomputer 11, so that it cannot be detected that there is a connection. The microcomputer 11 is not informed that the device is connected, and cannot return from sleep.

  Accordingly, an object of the present invention is to provide a power supply apparatus and a control method for the power supply apparatus that can suppress standby power and can be restored when a device is connected.

In order to solve the above-described problem, the present invention includes a conversion unit that converts an AC input into a DC output;
First and second power terminals connected to the first and second power lines, respectively, and first and second data terminals connected to the first and second data lines, respectively. A plurality of USB terminals to which at least one DC output of the output of the converter and the output of the secondary battery is supplied to the first and second power supply terminals;
A control microcomputer having a USB host function and at least a first data terminal of each of the plurality of USB terminals connected to the interrupt port;
The output data terminal of the control microcomputer and its input data terminal are connected, and the output data terminal includes a branch unit connected to each of the first and second data terminals of the plurality of USB terminals,
The branching unit detects whether or not a USB device is connected to each of the plurality of USB terminals,
When it is detected that a USB device is connected to a plurality of USB terminals, the control microcomputer communicates with the USB device, and after the authentication is established, the USB device can be supplied with a DC output.
When it is detected that the USB device is not connected to a plurality of USB terminals, the control microcomputer stops operating,
This is a power supply device in which the operation stop state of the control microcomputer is canceled by a signal change of the first data terminal of the USB terminal caused by the connection of the USB device.

In the present invention, at least one DC output of the output of the converter and the output of the secondary battery that converts AC input into DC output is supplied to the first and second power supply terminals of each of the plurality of USB terminals,
At least a first data terminal of each of a plurality of USB terminals is connected to an interrupt port of a control microcomputer having a USB host function,
Control method of power supply apparatus in which output data terminal of control microcomputer is connected to input data terminal of branching unit, and output data terminal of branching unit is connected to first and second data terminals of each of a plurality of USB terminals Because
When the branching unit detects whether or not a USB device is connected to each of the plurality of USB terminals, and when it is detected that the USB device is connected to the plurality of USB terminals, the control microcomputer communicates with the USB device. Performing a step of allowing the USB device to receive a DC output after authentication is established;
A step in which the control microcomputer stops operating when it is detected that the USB device is not connected to a plurality of USB terminals;
And a step of canceling the operation stop state of the control microcomputer by a signal change of the first data terminal of the USB terminal caused by the connection of the USB device.

  When the branching unit detects that the USB device is not connected to the USB port, the control microcomputer temporarily stops operating, and the branching unit also goes to sleep by disconnecting the handshake between the control microcomputer and the branching unit. Become. Therefore, standby power can be suppressed. The first data terminal of the USB port is connected to the interrupt terminal of the control microcomputer. The first data terminal of the USB port to which the USB device is connected changes from low level to high level. This change causes the control microcomputer to return to the normal operation from the operation stop state. A connection between the control microcomputer and the branch is established.

  The best mode for carrying out the invention (hereinafter referred to as an embodiment) will be described below. The embodiments described below are preferred specific examples of the present invention, and various technically preferable limitations are given. However, the scope of the present invention is not limited to the present invention in the following description. Unless otherwise specified, the present invention is not limited to these embodiments.

<One embodiment>
"Main part of one embodiment"
FIG. 3 shows an AC adapter to which the present invention is applied. The USB host control microcomputer 11 having a USB host function, the USB hub control IC 12 as a branching unit, and, for example, two USB ports 3a and 3b constitute a control unit related to USB. The USB host function is a function that can control connection to a USB device (device). The USB device can perform data transmission by receiving a control signal from the host.

  A USB host control microcomputer (hereinafter abbreviated as a control microcomputer as appropriate) 11 and a USB hub control IC 12 are connected through data lines D + and D−. The function of the USB hub control IC 12 is to branch the data line from the control microcomputer to the two USB ports 3a and 3b.

  The USB port 3a has a data terminal Ta + connected to the data line D + from the USB hub control IC 12, and a data terminal Ta- connected to the data line D-. Similarly, the USB port 3b has a data terminal Tb + connected to the data line D + from the USB hub control IC 12, and a data terminal Tb- connected to the data line D-. In FIG. 3, the power supply terminals of the USB ports 3a and 3b connected to the power supply line are omitted.

  The power supply lines D + and D− on the output side of the USB hub control IC 12 of the USB port 3 a are connected to the interrupt terminal of the control microcomputer 11. Similarly, the power supply lines D + and D− on the output side of the USB hub control IC 12 of the USB port 3 b are connected to the interrupt terminal of the control microcomputer 11. When an interrupt signal that changes from a low level to a high level is supplied to the interrupt terminal of the control microcomputer 11, the control microcomputer 11 returns from an operation stop state (sleep state) and enters an operation state.

In the USB 1.1 standard, two types of transfer modes were defined. There are a low speed mode (1.5 Mbps) and a full speed mode (12 Mbps). In the USB 2.0 standard, a high speed mode (480 Mbps) has been added as a faster transfer mode. The control microcomputer 11 and the USB hub control IC 12 can correspond to any of these transfer modes.

  When an operation controller of a USB device such as a game machine is connected to the USB port, the data line D- rises from a low level to a high level in the low speed mode in order to notify the control microcomputer 11 of the transfer mode of the USB device. . In the full speed mode and the high speed mode, the data line D + rises from the low level to the high level, and in the case of the high speed, the data further changes. Actually, since the devices in the low speed mode are decreasing, it can be said that it is sufficient to detect that the devices in the full speed mode and the high speed mode are connected. Therefore, only a change in the power supply line D + may be detected.

"Outline of operation of one embodiment"
The USB hub control IC 12 detects that the USB device is not connected to the USB ports 3a and 3b, and information indicating no connection is transmitted from the USB hub control IC 12 to the control microcomputer 11. The control microcomputer 11 recognizes that the USB device is not connected. The control microcomputer 11 that recognizes that the USB device is not connected enters the sleep state, and the USB hub control IC 12 also enters the sleep state. The sleep state means that the microcomputer temporarily stops operating and enters a power saving state. For example, the clock oscillation frequency of the control microcomputer is lowered as compared with the normal operation. As a result of the sleep, standby power can be reduced when no USB device is connected to the USB ports 3a and 3b.

  When a USB device is connected to one of the USB ports 3a and 3b, the data terminal D + or D− changes to a high level, and an interruption occurs in the control microcomputer 11. When the interrupt is generated, the control microcomputer 11 returns from the sleep state to the normal operation state. The control microcomputer 11 detects the connection of the USB hub control IC 12 and performs connection setting.

  When the connection setting is completed, data indicating that the device is connected to the USB port from the USB hub control IC 12 is transmitted to the control microcomputer 11. The control microcomputer 11 recognizes that the USB device is connected, and performs connection processing with the USB device. When communication is established with the USB device to which the control microcomputer 11 is connected and authentication is established, the USB device receives the DC power output of the AC adapter through the power terminal of the USB port.

"Configuration of one embodiment"
As shown in FIG. 4, in the embodiment of the present invention, AC power is supplied to the AC / DC converter 13 when the AC plug 1 is inserted into an AC outlet. For example, a + 5V DC power source is generated by the AC / DC converter 13. DC power is supplied to the power line (+). (-) Is a ground side line.

  The USB terminals 3a and 3b have first and second power terminals (Pa +, Pa−, Pb +, Pb−) connected to the power lines (+, −), respectively. The USB terminals 3a and 3b have first and second data terminals (Ta +, Ta−, Tb +, Tb−) connected to the data lines (D +, D−), respectively. USB plugs are connected to the USB ports 3a and 3b, and 5V DC power is supplied to the USB device via the USB cable. The USB device uses the DC power supply to charge an internal secondary battery, or uses the DC power supply as an operating power supply.

  A control microcomputer 11 having a USB host function and having data terminals (Ta +, Ta−, Tb +, Tb−) of the USB ports 3a and 3b connected to interrupt ports is provided. The output data terminal of the control microcomputer 11 and the input data terminal of the USB hub control IC 12 are connected. The output data terminal of the USB hub control IC 12 is connected to the respective data terminals (Ta +, Ta−, Tb +, Tb−) of the USB ports 3a and 3b.

  The DC power generated by the AC / DC converter 13 is supplied to the regulator 14, and the regulator 14 generates a DC power having a predetermined voltage, for example, + 3.3V. This DC power supply is used as a power supply for the control microcomputer 11 and the USB hub control IC 12.

  The control microcomputer 11 is a built-in microcomputer, and is configured around the function of the CPU 21 as shown in FIG. That is, a nonvolatile memory ROM (Read Only Memory) 22 and a working memory RAM (Random Access Memory) 23 in which programs are written are provided. Further, a clock generator 24, a timer 25, an IO port 26, a USB port 27, and an interrupt port 28 are provided.

  An accurate time is formed by dividing the clock, and the timer 25 measures the time. The output port of the IO port 26 outputs a low level or a high level, and the input port inputs a low level or a high level. The USB port 27 is a port connected to the USB hub control IC 12. The interrupt port 28 is a port to which interrupt signals from the USB ports 3a and 3b are input.

"Operation of an embodiment"
The flow of processing according to the embodiment of the present invention will be described with reference to the flowchart of FIG. The process surrounded by a solid line represents the operation of the control microcomputer 11, and the process surrounded by a broken line represents the operation of the USB hub control IC 12. In step S1, power is supplied to the AC adapter. Specifically, the AC plug 1 is inserted into the socket. Further, AC power is supplied by turning on the power switch.

  In step S2, the control microcomputer 11 is activated. In step S3, the USB hub control IC 12 is activated. In step S4, the control microcomputer 11 detects the connection of the USB hub control IC 12. In step S5, the control microcomputer 11 starts connection setting (port address allocation).

  In step S6, the USB hub control IC 12 detects whether a USB device is connected. When a USB device is connected to the USB port, the data line D− or D + rises from a low level to a high level in order to notify the control microcomputer 11 of the transfer mode of the USB device. When the USB hub control IC 12 detects that a USB device is connected, communication data with connection is transmitted from the USB hub control IC 12 to the control microcomputer 11.

  In step S7, authentication processing is performed, and normal processing (step S8) is performed according to the authentication result. The authentication process is a process in which the control microcomputer 11 confirms who is the USB device on the device side. When it is confirmed that the USB device is a legitimate device, the USB device receives the DC power output from the AC adapter. In other words, when the USB device recognizes that the AC adapter is a legitimate device, it receives output power. For example, when a secondary battery is charged, a lamp indicating charging is turned on. If it is not a legitimate device, it cannot receive DC power and the lamp is not lit.

  In step S9, the control microcomputer 11 determines whether or not a USB device is not connected for a certain time, for example, 20 ms. When the predetermined time has elapsed, it is determined that the USB device is not connected, and in step S10, the control microcomputer 11 enters the sleep mode. In the sleep mode, the clock oscillation frequency of the control microcomputer 11 is lowered, and handshaking with the USB hub control IC 12 is also stopped. When the handshake between the control microcomputer 11 and the USB hub control IC 12 is cut, the USB hub control IC 12 is also in the sleep mode. As a result, standby power is suppressed.

  In step S11, the control microcomputer 11 always monitors the interrupt port. When the external input to the interrupt port does not change, the sleep mode continues. When a USB device is connected to the USB port 3a or 3b, the interrupt port changes from low level to high level. When the change of the interrupt port occurs, in step S12, the normal state is restored from the sleep state.

  When the control microcomputer 11 returns to the normal operation state, connection of the USB hub control IC 12 is detected (step S4), and a port address is assigned to the USB hub control IC 12 (step S5). Then, whether or not the USB device is connected is detected (step S6).

"Modification"
The embodiment of the present invention has been described above, but the present invention is not limited to the embodiment, and various modifications and applications can be made without departing from the gist of the present invention. For example, when configuring a charging device, a secondary battery and a charge control circuit for the secondary battery are added to the configuration of the embodiment of the present invention described above. The microcomputer constituting the charge control circuit may have the function of the charge control microcomputer.

It is a block diagram which shows the outline of a charging device in the AC adapter which can apply this invention. It is a block diagram for connecting the problem of the conventional AC adapter. It is a block diagram for demonstrating the principal part of one embodiment of this invention. It is a block diagram of one embodiment of this invention. It is a functional block diagram of the control microcomputer in one embodiment of this invention. It is a flowchart for demonstrating the flow of operation | movement in one embodiment of this invention.

Explanation of symbols

1 ... AC plug 3a, 3b ... USB port 11 ... Control microcomputer 12 ... USB hub control IC
13... AC / DC converters Pa +, Pa−, Pb +, Pb−... Power terminals Ta +, Ta−, Tb +, Tb− connected to the power lines Data terminals connected to the data lines

Claims (7)

A converter for converting AC input to DC output;
First and second power terminals connected to the first and second power lines, respectively, and first and second data terminals connected to the first and second data lines, respectively. A plurality of USB terminals to which at least one DC output of the output of the converter and the output of the secondary battery is supplied to the first and second power supply terminals;
A control microcomputer having a USB host function, wherein at least the first data terminal of each of the plurality of USB terminals is connected to an interrupt port;
An output data terminal of the control microcomputer and its input data terminal are connected, and the output data terminal includes a branch unit connected to each of the first and second data terminals of the plurality of USB terminals,
The branching unit detects whether or not a USB device is connected to each of the plurality of USB terminals;
When it is detected that a USB device is connected to a plurality of USB terminals, the control microcomputer communicates with the USB device, and the USB device can receive the DC output after authentication is established. And
When it is detected that the USB device is not connected to the plurality of USB terminals, the control microcomputer stops operating,
A power supply apparatus in which an operation stop state of the control microcomputer is canceled by a signal change of the first data terminal of the USB terminal caused by connection of a USB device.   2. The power supply device according to claim 1, wherein the control microcomputer is activated when an AC input is supplied.   2. The power supply device according to claim 1, wherein the control microcomputer is put into a sleep state when a state in which the USB device is not connected to each of the USB terminals continues for a set time or longer.   The power supply apparatus according to claim 1, wherein the DC output is used as a charging power source for a secondary battery in a USB device connected to the USB terminal. DC output of at least one of the output of the conversion unit that converts AC input into DC output and the output of the secondary battery is supplied to the first and second power supply terminals of each of the plurality of USB terminals,
At least the first signal terminal of each of the plurality of USB terminals is connected to an interrupt port of a control microcomputer having a USB host function,
A power supply apparatus in which an output signal terminal of the control microcomputer is connected to an input signal terminal of a branch unit, and an output signal terminal of the branch unit is connected to each of the first and second signal terminals of the plurality of USB terminals Control method,
The branching unit detecting whether or not a USB device is connected to each of the plurality of USB terminals;
When it is detected that a USB device is connected to a plurality of USB terminals, the control microcomputer communicates with the USB device, and the USB device can receive the DC output after authentication is established. And steps
A step of stopping the operation of the control microcomputer when it is detected that a USB device is not connected to the plurality of USB terminals;
A control method of the power supply apparatus, comprising: a step of releasing the operation stop state of the control microcomputer by a signal change of the first signal terminal of the USB terminal caused by connecting a USB device.   6. The method of controlling a power supply device according to claim 5, wherein the control microcomputer is activated when an AC input is supplied.   6. The method of controlling a power supply device according to claim 5, wherein the control microcomputer is put into a sleep state when a state in which the USB device is not connected to each of the USB terminals continues for a set time or longer.

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