Electronic equipment, electronic systems, and control methods

Abstract

The present invention provides electronic devices, electronic systems, and control methods that can reduce the power consumption of an AC adapter. [Solution] The electronic device comprises: a power supply circuit that outputs power supplied from an AC adapter to a battery or a load of the electronic device; a first controller that communicates information necessary for the supply of power with the AC adapter via the channel and controls the power supply circuit; a switch positioned between the AC adapter and the first controller in the channel; and a second controller that transitions the AC adapter to the first state by setting the state of the switch to a connected state when the electronic device is in a third state, and transitions the AC adapter to the second state by setting the state of the switch to a disconnected state when the electronic device is in a fourth state in which power consumption is less than that of the third state.

Description

Technical Field

[0001] The present invention relates to an electronic device, an electronic system, and a control method.

Background Art

[0002] A portable electronic device such as a notebook or tablet personal computer or a smartphone generally has a battery and can charge the battery with power supplied from an AC adapter by connecting the AC adapter. Further, the electronic device not only operates with a system power supply generated by the power supplied from the battery, but can also operate with a system power supply generated by the power supplied from the AC adapter in parallel with charging the battery when the AC adapter is connected. An example of such an electronic device is disclosed in Patent Document 1 below.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the system of an electronic device transitions from an operating state to a standby state or a shutdown state, the power consumption of the system decreases. However, although the power required in the system decreases, a conventional AC adapter continues to operate in a normal state and consumes wasteful power.

[0005] An object of the present invention is to provide an electronic device, an electronic system, and a control method capable of reducing the power consumption of an AC adapter.

Means for Solving the Problems

[0006] One aspect of the present invention is an electronic device powered by power supplied from an AC adapter or battery, which switches between a first state and a second state having less power consumption than the first state depending on the voltage of a channel, comprising: a power supply circuit that outputs the power supplied from the AC adapter to the battery or the load of the electronic device; a first controller that communicates information necessary for the supply of power with the AC adapter via the channel and controls the power supply circuit; a switch positioned between the AC adapter and the first controller in the channel, which can switch between a connected state that electrically connects the AC adapter and the first controller and a disconnected state that electrically disconnects the AC adapter and the first controller; and a second controller that transitions the AC adapter to the first state by setting the state of the switch to the connected state when the electronic device is in a third state, and transitions the AC adapter to the second state by setting the state of the switch to the disconnected state when the electronic device is in a fourth state having less power consumption than the third state.

[0007] In one embodiment of the present invention, the electronic device may include a resistor connected in the channel to the node between the AC adapter and the switch and to ground.

[0008] In one embodiment of the present invention, when the electronic device is in the third state, the first controller may cause the power supply circuit to output the power supplied from the AC adapter to the battery and the load; when the electronic device transitions from the third state to the fourth state, the first controller may cause the power supply circuit to start outputting power from the battery to the load; and when the electronic device transitions from the fourth state to the third state, the first controller may communicate with the AC adapter via the channel to cause the AC adapter to start supplying power, cause the power supply circuit to stop outputting power from the battery to the load, and cause the power supply circuit to start outputting the power supplied from the AC adapter to the battery and the load.

[0009] In one embodiment of the present invention, after the electronic device transitions from the third state to the fourth state and the first controller causes the power supply circuit to start outputting power from the battery to the load, the second controller sets the state of the switch to the disconnected state, and after the electronic device transitions from the fourth state to the third state and the second controller sets the state of the switch to the connected state, the first controller causes the AC adapter to start supplying power and the power supply circuit to start outputting the power supplied from the AC adapter to the battery and the load, and the power supply circuit to stop outputting power from the battery to the load.

[0010] One aspect of the present invention is an electronic system comprising: an AC adapter that switches between a first state and a second state having less power consumption than the first state depending on the voltage of a channel; and an electronic device that operates on power supplied from the AC adapter or a battery, wherein the electronic device comprises: a power supply circuit that outputs the power supplied from the AC adapter to the battery or a load of the electronic device; a first controller that communicates information necessary for the supply of power with the AC adapter via the channel and controls the power supply circuit; a switch positioned between the AC adapter and the first controller in the channel and capable of switching between a connected state that electrically connects the AC adapter and the first controller and a disconnected state that electrically disconnects the AC adapter and the first controller; and a second controller that transitions the AC adapter to the first state by setting the state of the switch to the connected state when the electronic device is in a third state, and transitions the AC adapter to the second state by setting the state of the switch to the disconnected state when the electronic device is in a fourth state having less power consumption than the third state.

[0011] One aspect of the present invention is a method for controlling an electronic device that operates on power supplied from an AC adapter or battery, which switches between a first state and a second state having less power consumption than the first state depending on the voltage of a channel, wherein the electronic device comprises: a power supply circuit that outputs the power supplied from the AC adapter to the battery or a load of the electronic device; a first controller that communicates information necessary for the supply of power with the AC adapter via the channel and controls the power supply circuit; and a switch positioned between the AC adapter and the first controller in the channel, wherein when the electronic device is in a third state, the second controller transitions the AC adapter to the first state by setting the state of the switch to a connected state that electrically connects the AC adapter and the first controller; and when the electronic device is in a fourth state having less power consumption than the third state, the second controller transitions the AC adapter to the second state by setting the state of the switch to a disconnected state that electrically disconnects the AC adapter and the first controller. [Effects of the Invention]

[0012] According to the present invention, the power consumption of the AC adapter can be reduced. [Brief explanation of the drawing]

[0013] [Figure 1] This is an external view showing an example of an electronic device according to an embodiment of the present invention. [Figure 2] A block diagram showing an example of the hardware configuration of an electronic device according to an embodiment of the present invention. [Figure 3] This is a block diagram showing an example of the hardware configuration of an electronic system according to an embodiment of the present invention. [Figure 4] This flowchart shows an example of the operation of an AC adapter according to an embodiment of the present invention. [Figure 5] This flowchart shows an example of the operation of an electronic device according to an embodiment of the present invention. [Figure 6] This is a timing chart showing an example of the changes in channel voltage, AC adapter mode, and switch state according to an embodiment of the present invention. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the drawings.

[0015] Figure 1 is an external view showing an example of an electronic device according to an embodiment of the present invention. The electronic device 10 shown in Figure 1 is a clamshell-type (notebook-type) PC (Personal Computer). The electronic device 10 may also be a tablet-type PC or a smartphone, etc. The electronic device 10 is equipped with a battery 20 inside. An AC adapter 30 is also connected to the electronic device 10. The AC adapter 30 converts commercial alternating current (AC) power to direct current (DC) power to be input to the electronic device 10.

[0016] Battery 20 is a rechargeable battery for supplying power to the electronic device 10. Battery 20 can be reused repeatedly by charging it with power supplied from the AC adapter 30. For example, battery 20 is a lithium-ion battery. The electronic device 10 operates on power supplied from either the AC adapter 30 or battery 20.

[0017] The power supplied from the AC adapter 30 is output to the battery 20 and the load 200 (Figure 3) within the electronic device 10 system. The load 200 consumes power during system processing, which is realized when the CPU (Central Processing Unit) and other components within the electronic device 10 execute the OS (Operating System) and application programs that run on the OS. The load 200 fluctuates depending on the operating state of the system; for example, it becomes smaller when the system is idle.

[0018] The amount of power supplied from the AC adapter 30 to the electronic device 10 depends on the magnitude of the load 200. For example, when the load 200 is relatively large, the amount of power supplied from the AC adapter 30 to the electronic device 10 is relatively large. On the contrary, when the load 200 is relatively small, the amount of power supplied from the AC adapter 30 to the electronic device 10 is relatively small.

[0019] Therefore, when the electronic device 10 transitions to a state with low power consumption, the amount of power supplied from the AC adapter 30 to the electronic device 10 becomes relatively small. Also, the amount of power supplied from the AC adapter 30 to the electronic device 10 depends on the remaining amount of the battery 20. For example, when the battery 20 is fully charged, specifically when the remaining amount of the battery 20 is 95% or more, the battery 20 is not charged to protect the battery 20. Therefore, the amount of power supplied from the AC adapter 30 to the electronic device 10 for charging the battery 20 is almost zero. On the contrary, when the battery 20 is in a state other than the fully charged state, the amount of power supplied from the AC adapter 30 to the electronic device 10 for charging the battery 20 depends on the remaining amount of the battery 20.

[0020] If the output current of the AC adapter 30 is not large enough, the power conversion efficiency will decrease. The electronic device 10 has a power supply circuit 180 shown in FIGS. 2 and 3. The power supply circuit 180 generates power to be supplied to the battery 20 and the load 200 using the power supplied from the AC adapter 30, and outputs the generated power to the battery 20 and the load 200. If the output current of the power supply circuit 180 is not large enough, the power conversion efficiency will decrease.

[0021] [[ID=eleven]] Therefore, when the AC adapter 30 is connected to the electronic device 10, if the battery 20 reaches a fully charged state and the electronic device 10 transitions to a state with low power consumption, the power supplied from the AC adapter 30 to the electronic device 10 decreases. As a result, the AC adapter 30 and the electronic device 10 operate in a low-efficiency state, and the power supply circuit 180 of the electronic device 10 also operates in a low-efficiency state. If such operation continues, the AC adapter 30 and the power supply circuit 180 continue to consume power wastefully.

[0022] One of the standard specifications regarding power management of a computer is ACPI (Advanced Configuration and Power Interface). In ACPI, the power states of a device (from S0 to S5) are defined. The general power states defined by ACPI are as follows. In S0, the computer is in an operating state. In S1 and S2, the computer is in a standby state. In S3, the computer is in a sleep (standby) state. In S4, the computer is in a hibernation state. In S5, the computer is in a shutdown state.

[0023] The power state of the system of the electronic device 10 is set to any one of S0 to S5. When the AC adapter 30 is connected to the electronic device 10 and the power state of the system of the electronic device 10 is any one of S0 to S3, the power supply circuit 180 outputs power from the AC adapter 30 to the battery 20 and the load 200. When the battery 20 is in a fully charged state, in order to protect the battery 20, the power supply circuit 180 cuts off the power supply to the battery 20.

[0024] When the system of the electronic device 10 transitions to S4 or S5 with low power consumption, the power supply from the AC adapter 30 to the power supply circuit 180 is cut off, and power is output from the battery 20 to the load 200. The power supply circuit 180 stops generating power supplied to the battery 20 and power supplied to the load 200. Thereby, the power consumed by the AC adapter 30 and the power supply circuit 180 can be reduced.

[0025] When the power state of the electronic device 10's system is one of S0 to S3, the AC adapter 30 operates in normal mode. When the electronic device 10's system transitions to S4 or S5, the AC adapter 30 stops supplying power to the electronic device 10 and transitions to standby mode, which consumes less power than normal mode. The operating frequency of the AC adapter 30 in standby mode is lower than the operating frequency of the AC adapter 30 in normal mode. Because the operating mode of the AC adapter 30 transitions from normal mode to standby mode, the power consumed by the AC adapter 30 can be further reduced.

[0026] Figure 2 is a block diagram showing an example of the hardware configuration of the electronic device 10. The electronic device 10 includes a display unit 110, a USB (Universal Serial Bus) connector 120, an input device 130, a communication unit 140, a storage unit 150, an EC (Embedded Controller) 160, a system processing unit 170, a power supply circuit 180, and a PD controller 185.

[0027] The display unit 110 has a liquid crystal display (LCD) or an organic electroluminescent (EL) display, etc. The display unit 110 displays an image based on display data generated in system processing performed by the system processing unit 170.

[0028] The USB connector 120 is a connector for connecting peripheral devices that utilize USB. For example, the USB connector 120 is a USB Type-C connector. By connecting the AC adapter 30 to the USB connector 120, power can be supplied from the AC adapter 30. The electronic device 10 may also have a USB Type-A connector as the USB connector 120.

[0029] The input device 130 is an input unit that receives user input and includes, for example, a keyboard 131 and a touchpad 133. The input device 130 receives operations on the keyboard 131 and the touchpad 133 and outputs an operation signal indicating the operation to the EC160.

[0030] The communication unit 140 connects to other devices via a communication network, either wirelessly or wired, to enable communication and transmit and receive various types of data. For example, the communication unit 140 has a communication device such as a wired LAN interface like Ethernet® or a wireless LAN interface like Wi-Fi®. The communication unit 140 may also have a USB interface or a Bluetooth® interface.

[0031] The storage unit 150 has a storage medium such as an HDD (Hard Disk Drive), SSD (Solid State Drive), RAM (Random Access Memory), or ROM (Read Only Memory). The HDD or SSD stores various programs such as the OS, device drivers, and applications, as well as various data acquired by the operation of the programs.

[0032] The EC160 is a microcomputer comprising a CPU, RAM, ROM, and I / O (Input / Output) logic circuits. The EC160's CPU reads control programs pre-stored in its ROM, executes the read control programs, and performs its functions. For example, the EC160 operates independently of the system processing unit 170, giving instructions for transitions in the system's operating state (startup, transition to standby state, etc.) and managing its operating state. The EC160 is also connected to an input device 130 and a power supply circuit 180. The EC160 transmits operation information input to the input device 130 in response to user operations to the system processing unit 170, etc.

[0033] Furthermore, the EC160 communicates with the battery 20 to obtain information about the battery's status (remaining charge, voltage, etc.) and controls the charging process when the power supply circuit 180 charges the battery 20 using power supplied from the AC adapter 30.

[0034] Furthermore, the EC160 controls the supply of power from the battery 20 to the load 200 by instructing the PD controller 185 to cut off the power supply from the AC adapter 30 to the power circuit 180. Specifically, the EC160 performs the above control when the amount of power consumed by the battery 20 and the load 200 is lower than a predetermined reference value, or when the AC adapter 30 is removed from the electronic device 10.

[0035] For example, when the battery 20 is fully charged and the electronic device 10 transitions to S4 or S5, the EC160 performs the above control. Alternatively, when the battery 20 is fully charged and the amount of power consumed by the load 200 is lower than a predetermined reference value, the EC160 performs the above control. In other words, when the battery 20 is not charged and the amount of power consumed by the load 200 is lower than a predetermined reference value, the EC160 performs the above control. Alternatively, when the AC adapter 30 is disconnected from the electronic device 10, the EC160 performs the above control.

[0036] Furthermore, when the remaining charge of the battery 20 falls below a predetermined threshold, the EC160 instructs the PD controller 185 to resume power supply from the power supply circuit 180, thereby controlling the charging of the battery 20 using the power generated by the power supply circuit 180. Alternatively, the EC160 performs this control when the AC adapter 30 is connected to the electronic device 10. In other words, when power is needed to charge the battery 20, the EC160 restarts power supply to the power supply circuit 180 and charges the battery 20 using the power supplied from the AC adapter 30.

[0037] Furthermore, the EC160 controls the transition of the AC adapter 30 from normal mode to standby mode or from standby mode to normal mode. Specifically, the EC160 performs this control by controlling the switch 190 shown in Figure 3.

[0038] The power supply circuit 180 generates power to supply to each part of the electronic device 10 based on the power supplied from the AC adapter 30 or the battery 20. For example, the power supply circuit 180 has a DC / DC converter, etc., which converts the voltage supplied from the AC adapter 30 or the battery 20 to a specified voltage and outputs that voltage to the system processing unit 170, etc. The power supply circuit 180 also has a charging circuit which charges the battery 20 based on the power supplied from the AC adapter 30.

[0039] The PD controller 185 performs control corresponding to USB PD (Power Delivery). When the AC adapter 30 is connected to the USB connector 120, the PD controller 185 manages the power supply from the AC adapter 30. For example, the PD controller 185 controls the amount of power supplied from the AC adapter 30.

[0040] The system processing unit 170 includes a CPU 171, a GPU (Graphics Processing Unit) 172, a memory controller 173, an I / O controller 174, and system memory 175. Through system processing by the OS, it is possible to execute various application software processes on the OS. The CPU 171 and GPU 172 are sometimes collectively referred to as the processor.

[0041] The CPU 171 controls the operating state of the system, such as system startup and transitions to standby (sleep) states, based on instruction information from the EC 160. For example, if the system is in standby mode and the EC 160 inputs a startup instruction in response to user input, the CPU 171 transitions from standby to normal operating state. For example, during startup, when power is supplied from the power supply circuit 180 and a startup instruction is received from the EC 160, the CPU 171 starts the startup process. In the startup process, the CPU 171 detects and initializes a minimum number of devices, such as the system memory 175 and the storage unit 150 (preboot). The CPU 171 loads the system firmware from the storage unit 150 into the system memory 175 and detects and initializes devices such as the communication unit 140 and the display unit 110 (post-processing). Initialization includes processing such as setting initial parameters. In the transition from standby (sleep) to normal operating state (resume), some post-processing may be omitted. After the boot process is complete, CPU171 begins executing system processes performed by the OS.

[0042] The GPU 172 is connected to the display unit 110. The GPU 172 performs image processing based on the control of the CPU 171 and generates display data. The GPU 172 outputs the generated display data to the display unit 110. The CPU 171 and GPU 172 may be integrated and formed as a single core, or the load may be shared between the CPU 171 and GPU 172 which are formed as individual cores. The number of processors is not limited to one, but may be multiple.

[0043] The memory controller 173 controls the reading and writing of data from the system memory 175 and storage unit 150, etc., by the CPU 171 and GPU 172. The I / O controller 174 controls the input and output of data from the communication unit 140, display unit 110, and EC 160. The system memory 175 is used as a reading area for the processor's execution program and a work area for writing processing data.

[0044] Figure 3 is a block diagram showing an example of the hardware configuration of an electronic system including an electronic device 10 and an AC adapter 30. Only the configuration related to power supply from the AC adapter 30 is shown in Figure 3. The electronic device 10 includes a battery 20, a USB connector 120, an EC160, a power supply circuit 180, a PD controller 185, a switch 190, a resistor 195, and a load 200.

[0045] The AC adapter 30 outputs power for the operation of the electronic device 10 by outputting a predetermined voltage to the electronic device 10. The AC adapter 30 is connected to the USB connector 120 and outputs power to the electronic device 10 via the USB connector 120. The AC adapter 30 is also connected to a channel CC1 called CC (Configuration Channel), and communicates information necessary for power supply with the PD controller 185 via channel CC1. The AC adapter 30 has an internal current source and outputs current to channel CC1. The AC adapter 30 monitors the voltage of channel CC1 and switches between normal mode and standby mode according to the voltage of channel CC1.

[0046] Switch 190 is inserted into channel CC1 and connected to the AC adapter 30 and the PD controller 185. Switch 190 can switch between a connected state, which electrically connects the AC adapter 30 and the PD controller 185, and a disconnected state, which electrically disconnects the AC adapter 30 and the PD controller 185.

[0047] The PD controller 185 is connected to channel CC1 via switch 190. When switch 190 is connected, the PD controller 185 communicates with the AC adapter 30.

[0048] When the electronic device 10 is in any of states S0 to S3, the PD controller 185 controls the power supply circuit 180 to output power supplied from the AC adapter 30 to the battery 20 and load 200. When the electronic device 10 is in state S4 or S5, the display unit 110, communication unit 140, and system processing unit 170, etc., are idle or stopped, but the EC160 and PD controller 185 are operational. When the electronic device 10 transitions to state S4 or S5, the PD controller 185 controls the power supply circuit 180 to stop outputting power supplied from the AC adapter 30 to the battery 20 and load 200, and to start outputting power from the battery 20 to the load 200.

[0049] After the above process is executed, EC160 sets the state of switch 190 to the disconnected state. At this time, AC adapter 30 transitions to standby mode based on the voltage of channel CC1. AC adapter 30 also stops supplying power to electronic device 10. AC adapter 30 continues to monitor the voltage of channel CC1 even in standby mode.

[0050] When the electronic device 10 transitions from S4 or S5 to any one of S0 to S3, the EC160 sets the state of the switch 190 to the connected state. At this time, the AC adapter 30 transitions to normal mode based on the voltage of channel CC1. Subsequently, the PD controller 185 controls the power supply circuit 180 to start outputting power supplied from the AC adapter 30 to the battery 20 and load 200, and to stop outputting power from the battery 20 to the load 200.

[0051] The PD controller 185 communicates with the AC adapter 30 via channel CC1 to initiate power supply. The AC adapter 30 starts supplying power to the electronic device 10 based on the information received from the PD controller 185 via channel CC1. The PD controller 185 controls the power supply circuit 180 to output the power supplied from the AC adapter 30 to the battery 20 and the load 200.

[0052] The EC160 detects whether the AC adapter 30 is connected to or disconnected from the electronic device 10 by monitoring the voltage of channel CC1 at node N1 between the AC adapter 30 and the switch 190. Resistor 195 is connected to node N1 and to ground. The resistance of resistor 195 is, for example, 300 kilohms, and the internal resistance of the PD controller 185 is, for example, 5 kilohms. The resistance of resistor 195 is sufficiently greater than the internal resistance of the PD controller 185.

[0053] Even when the AC adapter 30 is disconnected from the electronic device 10, the EC160 may mistakenly detect that the AC adapter 30 is connected to the electronic device 10 based on the voltage generated across the parasitic capacitance of channel CC1. Because resistor 195 discharges the parasitic capacitance of channel CC1, the EC160 can reliably detect that the AC adapter 30 has been disconnected from the electronic device 10.

[0054] When the AC adapter 30 is disconnected from the electronic device 10, the power supply from the AC adapter 30 to the electronic device 10 stops. Therefore, the PD controller 185 controls the power supply circuit 180 to stop the output of power supplied from the AC adapter 30 to the battery 20 and load 200, and to start the output of power from the battery 20 to the load 200. When the AC adapter 30 is connected to the electronic device 10, the PD controller 185 controls the power supply circuit 180 to output power supplied from the AC adapter 30 to the battery 20 and load 200.

[0055] Figure 4 is a flowchart illustrating an example of the operation of the AC adapter 30. The operation of the AC adapter 30 will be explained with reference to Figure 4. When the AC adapter 30 is connected to the electronic device 10 and operating in normal mode, the AC adapter 30 starts the process shown in Figure 4.

[0056] (Step S100) The AC adapter 30 detects the voltage of channel CC1 and determines, based on the voltage of channel CC1, whether the AC adapter 30 has been disconnected from the electronic device 10 or whether the switch 190 has transitioned to the off state.

[0057] When the AC adapter 30 is disconnected from the electronic device 10, the voltage of channel CC1 changes, for example, from 1.7V to 3.3V. When the AC adapter 30 is connected to the electronic device 10 and the switch 190 transitions from the connected state to the disconnected state, the voltage of channel CC1 also changes, for example, from 1.7V to 3.3V. Based on this voltage change, the AC adapter 30 detects that it has been disconnected from the electronic device 10 or that the switch 190 has transitioned to the disconnected state.

[0058] Step S101 is performed if the AC adapter 30 is removed from the electronic device 10 or if the switch 190 transitions to the off state. Otherwise, step S100 is performed again.

[0059] (Step S101) The AC adapter 30 transitions from normal mode to standby mode and stops supplying power to the electronic device 10. The operating frequency of the AC adapter 30 in standby mode is lower than the operating frequency of the AC adapter 30 in normal mode. When the AC adapter 30 is disconnected from the electronic device 10, the voltage of channel CC1 is, for example, 3.3V. When the AC adapter 30 is connected to the electronic device 10 and transitions to standby mode, the voltage of channel CC1 changes from, for example, 3.3V to 1.5V.

[0060] (Step S102) The AC adapter 30 detects the voltage of channel CC1 and determines, based on the voltage of channel CC1, whether the AC adapter 30 is connected to the electronic device 10 or whether the switch 190 has transitioned to a connected state.

[0061] When switch 190 is in the connected state and AC adapter 30 is connected to electronic device 10, the voltage of channel CC1 changes from, for example, 3.3V to 0V. Based on this voltage change, AC adapter 30 detects that it is connected to electronic device 10. When AC adapter 30 is connected to electronic device 10 and switch 190 transitions from the disconnected state to the connected state, the voltage of channel CC1 changes from, for example, 1.5V to 0V. Based on this voltage change, AC adapter 30 detects that switch 190 has transitioned to the connected state.

[0062] Step S103 is executed when the AC adapter 30 is connected to the electronic device 10 or when the switch 190 transitions to the connected state. Otherwise, step S102 is executed again.

[0063] (Step S103) The AC adapter 30 transitions from standby mode to normal mode and begins supplying power to the electronic device 10. The voltage of channel CC1 changes, for example, from 0V to 1.7V. Then, step S100 is performed.

[0064] When the AC adapter 30 is in standby mode, it cannot communicate with the PD controller 185. Therefore, the PD controller 185 cannot communicate with the AC adapter 30 to transition it to normal mode. The power required for the AC adapter 30 to detect the voltage of channel CC1 is less than the power required for the AC adapter 30 to communicate with the PD controller 185, so the AC adapter 30 can detect the voltage of channel CC1 in standby mode. The EC160 can transition the AC adapter 30 to normal mode by transitioning the switch 190 to the off state.

[0065] Figure 5 is a flowchart illustrating an example of the operation of the electronic device 10. The operation of the electronic device 10 will be explained with reference to Figure 5. When the power state of the electronic device 10 system is one of S0 to S3, the electronic device 10 starts the process shown in Figure 5.

[0066] (Step S200) The EC160 detects the voltage of channel CC1 by detecting the voltage of node N1. Based on the voltage of channel CC1, the EC160 determines whether or not the AC adapter 30 is connected to the electronic device 10.

[0067] When switch 190 is connected and AC adapter 30 is connected to electronic device 10, the voltage of channel CC1 changes, for example, from 3.3V to 0V. Based on this voltage change, EC160 detects that AC adapter 30 has been connected to electronic device 10.

[0068] If the AC adapter 30 is connected to the electronic device 10, step S201 is performed. If the AC adapter 30 is not connected to the electronic device 10, step S200 is performed again.

[0069] (Step S201) The EC160 instructs the PD controller 185 to begin supplying power from the AC adapter 30. The PD controller 185 communicates information necessary for power supply with the AC adapter 30 via channel CC1. The AC adapter 30 and the PD controller 185 communicate information such as the amount of power that the AC adapter 30 can supply and the amount of power that the electronic device 10 requires.

[0070] (Step S202) The PD controller 185 controls the power supply circuit 180 and outputs the power supplied from the AC adapter 30 to the battery 20 and the load 200.

[0071] (Step S203) The EC160 detects the voltage of channel CC1 by detecting the voltage of node N1. Based on the voltage of channel CC1, the EC160 determines whether the AC adapter 30 has been disconnected from the electronic device 10.

[0072] When the AC adapter 30 is disconnected from the electronic device 10, the voltage across channel CC1 changes, for example, from 1.7V to 3.3V. Based on this voltage change, the EC160 detects that the AC adapter 30 has been disconnected from the electronic device 10.

[0073] If the AC adapter 30 is disconnected from the electronic device 10, step S204 is performed. If the AC adapter 30 is connected to the electronic device 10, step S205 is performed.

[0074] (Step S204) The EC160 instructs the PD controller 185 to begin supplying power from the battery 20. The PD controller 185 controls the power supply circuit 180 to stop the output of power supplied from the AC adapter 30 to the battery 20 and load 200, and to start the output of power from the battery 20 to the load 200. Then, step S200 is executed.

[0075] (Step S205) EC160 determines whether the system of the electronic device 10 has transitioned to S4 or S5. If the system has transitioned to S4 or S5, step S206 is executed. If the system has not transitioned to S4 or S5, step S203 is executed.

[0076] (Step S206) The EC160 instructs the PD controller 185 to begin supplying power from the battery 20. The PD controller 185 controls the power supply circuit 180 to stop the output of power supplied from the AC adapter 30 to the battery 20 and load 200, and to start the output of power from the battery 20 to the load 200.

[0077] (Step S207) EC160 sets the state of switch 190 to the disconnected state.

[0078] (Step S208) EC160 detects the voltage of channel CC1 by detecting the voltage of node N1. Based on the voltage of channel CC1, EC160 determines whether the AC adapter 30 has been disconnected from the electronic device 10. Step S208 is the same as step S203.

[0079] If the AC adapter 30 is disconnected from the electronic device 10, step S209 is performed. If the AC adapter 30 is connected to the electronic device 10, step S210 is performed.

[0080] (Step S209) EC160 sets the state of switch 190 to connected state. Then, step S200 is executed.

[0081] (Step S210) EC160 determines whether the system of the electronic device 10 has transitioned to one of S0 to S3. If the system has transitioned to one of S0 to S3, step S211 is executed. If the system is in S4 or S5, step S208 is executed.

[0082] (Step S211) EC160 sets the status of switch 190 to connected state.

[0083] (Step S212) EC160 instructs PD controller 185 to start supplying power from AC adapter 30. PD controller 185 communicates the necessary information for power supply with AC adapter 30 via channel CC1. PD controller 185 controls power supply circuit 180 to output power supplied from AC adapter 30 to battery 20 and load 200. Subsequently, EC160 instructs PD controller 185 to stop supplying power from battery 20. PD controller 185 controls power supply circuit 180 to stop outputting power from battery 20 to load 200. Step S203 is then executed.

[0084] Figure 6 is a timing chart showing an example of the changes in the voltage (Vcc) of channel CC1 detected by the AC adapter 30, the mode of the AC adapter 30, and the state of the switch 190.

[0085] In the initial state, the AC adapter 30 is disconnected from the electronic device 10 and is in standby mode S. When the AC adapter 30 is disconnected from the electronic device 10, the voltage of channel CC1 is 3.3V. Also, the system of the electronic device 10 is in one of S0 to S3, and the switch 190 is in connected state C.

[0086] At timing T1, the AC adapter 30 is connected to the electronic device 10. At this time, the PD controller 185 and resistor 195 are connected in parallel to channel CC1, and the PD controller 185, which has a small resistance, becomes the main load on channel CC1. The AC adapter 30 is in standby mode S, and because the current output from the AC adapter 30 to channel CC1 is small, the voltage of channel CC1 changes to 0V. The AC adapter 30 detects the change in the voltage of channel CC1 and transitions to normal mode N at timing T2. At this time, the current output from the AC adapter 30 to channel CC1 increases, and the voltage of channel CC1 changes to 1.7V.

[0087] Subsequently, the system of the electronic device 10 transitions to S4 or S5. At timing T3, EC160 sets the state of switch 190 to the disconnected state D. At this time, the resistor 195 with a high resistance becomes the main load of channel CC1, so the voltage of channel CC1 changes to 3.3V. The AC adapter 30 detects the change in the voltage of channel CC1 and transitions to standby mode S at timing T4. At this time, the current output from the AC adapter 30 to channel CC1 decreases, and the voltage of channel CC1 changes to 1.5V.

[0088] Subsequently, the system of the electronic device 10 transitions to one of S0 to S3. At timing T5, EC160 sets the state of switch 190 to connected state C. At this time, the PD controller 185 and resistor 195 are connected in parallel to channel CC1, and the PD controller 185, which has a smaller resistance, becomes the main load on channel CC1. The AC adapter 30 is in standby mode S, and because the current output from the AC adapter 30 to channel CC1 is small, the voltage of channel CC1 changes to 0V. The AC adapter 30 detects the change in the voltage of channel CC1 and transitions to normal mode N at timing T6. At this time, the current output from the AC adapter 30 to channel CC1 increases, and the voltage of channel CC1 changes to 1.7V.

[0089] At timing T7, the AC adapter 30 is disconnected from the electronic device 10. Since channel CC1 is opened, the voltage of channel CC1 changes to 3.3V. The AC adapter 30 detects the change in channel CC1 voltage and transitions to standby mode S.

[0090] When the AC adapter 30 is disconnected from the electronic device 10, the resistor 195 discharges the parasitic capacitance of channel CC1. Therefore, the EC160 can reliably detect that the AC adapter 30 has been disconnected from the electronic device 10.

[0091] As described above, the AC adapter 30 switches between a normal mode (first state) and a standby mode (second state) with lower power consumption than the normal mode, depending on the voltage of channel CC1. The electronic device 10 operates on power supplied from the AC adapter 30 or the battery 20. The power supply circuit 180 outputs the power supplied from the AC adapter 30 to the battery 20 or the load 200 of the electronic device 10. The PD controller 185 (first controller) communicates information necessary for power supply with the AC adapter 30 via channel CC1 and controls the power supply circuit 180. The switch 190 is located between the AC adapter 30 and the PD controller 185 on channel CC1. The switch 190 can switch between a connected state, which electrically connects the AC adapter 30 and the PD controller 185, and a disconnected state, which electrically disconnects the AC adapter 30 and the PD controller 185. The EC160 (second controller) transitions the AC adapter 30 to normal mode by setting the state of switch 190 to connected when the electronic device 10 is in one of the states S0 to S3 (third state). The EC160 transitions the AC adapter 30 to standby mode by setting the state of switch 190 to disconnected when the electronic device 10 is in S4 or S5 (fourth state), which has a lower power consumption than S0 to S3.

[0092] The electronic device 10 includes a resistor 195 connected to node N1 between the AC adapter 30 and the switch 190 and to ground in channel CC1.

[0093] When the electronic device 10 is in any of states S0 to S3, the PD controller 185 instructs the power supply circuit 180 to output power supplied from the AC adapter 30 to the battery 20 and the load 200. When the electronic device 10 transitions from any of states S0 to S3 to S4 or S5, the PD controller 185 instructs the power supply circuit 180 to start outputting power from the battery 20 to the load 200. When the electronic device 10 transitions from S4 or S5 to any of states S0 to S3, the PD controller 185 communicates with the AC adapter 30 via channel CC1 to start supplying power to the AC adapter 30, to stop outputting power from the battery 20 to the load 200 to the power supply circuit 180, and to start outputting power supplied from the AC adapter 30 to the battery 20 and the load 200.

[0094] After the electronic device 10 transitions from one of S0 to S3 to S4 or S5, and the PD controller 185 causes the power supply circuit 180 to start outputting power from the battery 20 to the load 200, the EC160 sets the state of the switch 190 to the disconnected state. After the electronic device 10 transitions from S4 or S5 to one of S0 to S3, and the EC160 sets the state of the switch 190 to the connected state, the PD controller 185 causes the AC adapter 30 to start supplying power, and causes the power supply circuit 180 to start outputting the power supplied from the AC adapter 30 to the battery 20 and the load 200, and causes the power supply circuit 180 to stop outputting power from the battery 20 to the load 200.

[0095] The EC160 transitions the AC adapter 30 into standby mode by setting the state of the switch 190 to the disconnected state when the electronic device 10 is in S4 or S5. This reduces the power consumption of the AC adapter 30.

[0096] Furthermore, because resistor 195 discharges the parasitic capacitance of channel CC1, EC160 can reliably detect that the AC adapter 30 has been removed from the electronic device 10.

[0097] Furthermore, when the electronic device 10 transitions to S4 or S5, the power supply from the AC adapter 30 to the battery 20 and load 200 stops, and the AC adapter 30 transitions to standby mode, thus further reducing the power consumption of the AC adapter 30.

[0098] While embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to the embodiments described above, and may include design changes and the like that do not depart from the spirit of the present invention. [Explanation of Symbols]

[0099] 10 Electronic devices, 20 Batteries, 30 AC adapters, 160 EC, 180 Power circuits, 185 PD controllers, 190 Switches, 195 Resistors, 200 Loads

Claims

1. An electronic device powered by an AC adapter or battery, which switches between a first state and a second state with lower power consumption than the first state depending on the channel voltage, A power supply circuit that outputs the power supplied from the AC adapter to the battery or the load of the electronic device, A first controller that communicates information necessary for supplying the aforementioned power to the AC adapter via the channel and controls the power supply circuit, A switch is provided in the channel between the AC adapter and the first controller, and capable of switching between a connected state in which the AC adapter and the first controller are electrically connected, and a disconnected state in which the AC adapter and the first controller are electrically disconnected. A second controller that transitions the AC adapter to the first state by setting the switch state to the connected state when the electronic device is in the third state, and transitions the AC adapter to the second state by setting the switch state to the disconnected state when the electronic device is in the fourth state, in which power consumption is lower than that of the third state, Electronic devices equipped with these features.

2. The channel includes a resistor connected to the node between the AC adapter and the switch and to ground. The electronic device according to claim 1.

3. When the electronic device is in the third state, the first controller causes the power supply circuit to output the power supplied from the AC adapter to the battery and the load. When the electronic device transitions from the third state to the fourth state, the first controller causes the power supply circuit to start outputting power from the battery to the load. When the electronic device transitions from the fourth state to the third state, the first controller communicates with the AC adapter via the channel to cause the AC adapter to start supplying power, to cause the power supply circuit to stop outputting power from the battery to the load, and to cause the power supply circuit to start outputting the power supplied from the AC adapter to the battery and the load. The electronic device according to claim 1 or claim 2.

4. After the electronic device transitions from the third state to the fourth state, and the first controller causes the power supply circuit to start outputting power from the battery to the load, the second controller sets the state of the switch to the disconnected state. After the electronic device transitions from the fourth state to the third state, and the second controller sets the switch to the connected state, the first controller causes the AC adapter to start supplying power, the power supply circuit to start outputting the power supplied from the AC adapter to the battery and the load, and the power supply circuit to stop outputting power from the battery to the load. The electronic device according to claim 3.

5. An AC adapter that switches between a first state and a second state with lower power consumption than the first state, depending on the channel voltage. An electronic device that operates using power supplied from the aforementioned AC adapter or battery, An electronic system comprising, The aforementioned electronic device is A power supply circuit that outputs the power supplied from the AC adapter to the battery or the load of the electronic device, A first controller that communicates information necessary for supplying the aforementioned power to the AC adapter via the channel and controls the power supply circuit, A switch is provided in the channel between the AC adapter and the first controller, and capable of switching between a connected state in which the AC adapter and the first controller are electrically connected, and a disconnected state in which the AC adapter and the first controller are electrically disconnected. A second controller that transitions the AC adapter to the first state by setting the switch state to the connected state when the electronic device is in the third state, and transitions the AC adapter to the second state by setting the switch state to the disconnected state when the electronic device is in the fourth state, in which power consumption is lower than that of the third state, An electronic system equipped with the following features.

6. A control method for electronic equipment that operates on power supplied from an AC adapter or battery, which switches between a first state and a second state with lower power consumption than the first state depending on the voltage of the channel, The aforementioned electronic device is A power supply circuit that outputs the power supplied from the AC adapter to the battery or the load of the electronic device, The first controller communicates information necessary for supplying power to the AC adapter via the channel and controls the power supply circuit. A switch is positioned between the AC adapter and the first controller in the channel, Equipped with, When the electronic device is in the third state, the second controller causes the AC adapter to transition to the first state by setting the state of the switch to a connected state in which the AC adapter and the first controller are electrically connected. When the electronic device is in a fourth state in which its power consumption is lower than that of the third state, the second controller causes the AC adapter to transition to the second state by setting the state of the switch to a disconnected state that electrically disconnects the AC adapter from the first controller. Control method.

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