Power circuits and power systems

Abstract

According to the present invention, a power supply circuit that charges a battery and supplies power to a load circuit includes: a DC / DC converter that converts power of a first direct-current voltage supplied from an external power supply to power of a second direct-current voltage and supplies the power of the second direct-current voltage to the load circuit; a charging control circuit that is connected to the external power supply in parallel with the DC / DC converter, converts power of the first direct-current voltage to power of a third direct-current voltage, and supplies the power of the third direct-current voltage to the battery; and a switch circuit that switches between a first mode in which power is supplied from the DC / DC converter to the load circuit and a second mode in which power is supplied from the battery to the load circuit.

Description

Technical Field

[0001] The present disclosure relates to a power supply circuit and a power supply system.

Background Art

[0002] Various electronic devices using batteries are in use. Regarding charging and discharging of a battery, for example, Japanese Patent Application Laid-Open No. 2004-023832 discloses a configuration in which power is supplied from a power supply means and the power converted by a DC / DC converter is supplied to a power storage means and a load circuit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A DC / DC converter that supplies power to a power storage means has a configuration suitable for precise voltage adjustment, and there is a possibility that the conversion efficiency may slightly decrease. Therefore, in a circuit configuration that supplies power from the DC / DC converter to a load circuit, there is room for improvement in terms of the conversion efficiency of voltage conversion.

[0005] One object of the present disclosure is to improve the conversion efficiency of voltage conversion in a power supply circuit that charges a battery and supplies power to a load circuit.

Means for Solving the Problems

[0006] According to one embodiment, a power supply circuit is provided for charging a battery and supplying power to a load circuit. The power supply circuit includes a DC / DC converter that converts power of a first DC voltage supplied from an external power source into power of a second DC voltage and supplies power of the second DC voltage to the load circuit; a charging control circuit connected in parallel with the DC / DC converter to the external power source, which converts power of the first DC voltage into power of a third DC voltage and supplies power of the third DC voltage to the battery; and a switch circuit that switches between a first mode in which power is supplied from the DC / DC converter to the load circuit and a second mode in which power is supplied from the battery to the load circuit.

[0007] In this configuration, in the first mode, power from a second DC voltage converted by a DC / DC converter is supplied to the load circuit, and in the second mode, power is supplied to the load circuit from the battery. The battery is charged by power from a third DC voltage converted by a charge control circuit. This mode switching enables voltage conversion suitable for both power supply from an external power source to the load circuit and power supply from an external power source to the battery. This improves the conversion efficiency of the voltage conversion in the power supply circuit that charges the battery and supplies power to the load circuit.

[0008] In a third mode, which is different from the first and second modes, the charging control circuit may supply at least a portion of the power of the third DC voltage to the load circuit. With this configuration, power supplied from an external power source can be supplied to the load circuit from either the DC / DC converter or the charging control circuit, allowing for the selection of an appropriate voltage conversion depending on the situation.

[0009] In a fourth mode, distinct from the first, second, and third modes, both the DC / DC converter and the charging control circuit may supply power to the load circuit. With this configuration, since both the DC / DC converter and the charging control circuit supply power to the load circuit, power can be supplied stably even when the load circuit requires more power.

[0010] The conversion efficiency of the DC / DC converter in converting power from a first DC voltage to power from a second DC voltage may be higher than the conversion efficiency of the charging control circuit in converting power from a first DC voltage to power from a third DC voltage. With this configuration, the power supply to the load circuit can be made more efficient by selecting the circuit responsible for voltage conversion depending on the situation.

[0011] The system may be configured such that if the first DC voltage is within a predetermined DC voltage range, the first mode is selected, and if the first DC voltage is outside the predetermined DC voltage range, the third mode is selected. With this configuration, the circuit responsible for voltage conversion can be appropriately selected from among the DC / DC converter and the charging control circuit depending on the voltage of the first DC voltage.

[0012] The load circuit may be capable of outputting images to an integrated monitor within the electronic device and to an external monitor located outside the electronic device. The switch circuit may switch to the first mode when the first DC voltage is within a predetermined DC voltage range and an image is output to the external monitor, and the switch circuit may switch to the third mode when the first DC voltage is within a predetermined DC voltage range and an image is output to the integrated monitor. With this configuration, when outputting an image to an external monitor, the processing load on the load circuit is expected to increase, so power can be appropriately provided to correspond to the increased processing load.

[0013] In the first mode, the charging control circuit may supply power of a third DC voltage to the battery. With this configuration, the battery can be charged in parallel with the DC / DC converter supplying power to the load circuit, so there is no need to set aside time for separate battery charging.

[0014] The power supply circuit may further include a first conductive path connecting the output side of the DC / DC converter to the first input of the switch circuit, a second conductive path connecting the output side of the charge control circuit to the second input of the switch circuit, and a third conductive path connecting the output of the switch circuit to the load circuit. With this configuration, the switch circuit can be controlled to select the circuit that supplies power to the load circuit from among the DC / DC converter and the charge control circuit.

[0015] The switch circuit may include a switch that connects either the first or second conductive path to the third conductive path, and a rectifier element positioned between the second and third conductive paths to allow current to pass from the second to the third conductive path. With this configuration, when the power required by the load circuit is greater than the power that can be supplied by the DC / DC converter, power can be supplied from the charging control circuit via the rectifier element in addition to the power supplied from the DC / DC converter.

[0016] The power supply circuit may further include a fourth conductive path connecting the battery and the charge control circuit. In the second mode, power from the battery may be supplied to the load circuit via the second conductive path, the switch circuit, and the third conductive path. With this configuration, power from the battery is supplied to the load circuit via the same path that the charge control circuit uses to supply voltage-converted power, thus simplifying the circuit configuration.

[0017] In another embodiment, a power supply system is provided for charging a battery and supplying power to a load circuit. The power supply system includes a DC / DC converter that converts power of a first DC voltage supplied from an external power source into power of a second DC voltage and supplies power of the second DC voltage to the load circuit; a charging control circuit connected in parallel with the DC / DC converter to the external power source, which converts power of the first DC voltage into power of a third DC voltage and supplies power of the third DC voltage to the battery; a switch circuit that switches between a first mode in which power is supplied from the DC / DC converter to the load circuit and a second mode in which power is supplied from the battery to the load circuit; and a power management unit that gives control commands to the switch circuit based on the power supplied from the external power source. With this configuration, the power management unit can appropriately select between the first mode and the second mode depending on the situation.

[0018] The power supply system may further include auxiliary equipment that supplies power of a first DC voltage. With this configuration, power of the first DC voltage can be supplied stably from the auxiliary equipment.

[0019] The power management unit may be located in the auxiliary equipment. With this configuration, it is not necessary to provide a power management unit in the electronic equipment including the power supply circuit, thus reducing the weight of the electronic equipment. [Effects of the Invention]

[0020] According to this disclosure, the conversion efficiency of voltage conversion can be improved in a power supply circuit that charges a battery and supplies power to a load circuit. [Brief explanation of the drawing]

[0021] [Figure 1] This is a schematic diagram showing an example of the overall configuration of an electronic device including a power supply circuit according to this embodiment. [Figure 2] This is a schematic diagram showing an example of using an electronic device including a power supply circuit according to this embodiment in portable mode. [Figure 3] This is a schematic diagram illustrating an example of using an electronic device including a power supply circuit according to this embodiment in an external power supply mode. [Figure 4] It is a schematic diagram showing an internal configuration example of an electronic device including a power supply circuit according to this embodiment. [Figure 5] It is a schematic diagram showing a configuration example of a power supply system including a power supply circuit according to this embodiment. [Figure 6] It is a schematic diagram showing a configuration example of a dock according to this embodiment. [Figure 7] It is a diagram for explaining the operation in the first mode of a power supply system including a power supply circuit according to this embodiment. [Figure 8] It is a diagram for explaining the operation in the second mode of a power supply system including a power supply circuit according to this embodiment. [Figure 9] It is a diagram for explaining the operation in the third mode of a power supply system including a power supply circuit according to this embodiment. [Figure 10] It is a diagram for explaining the operation in the fourth mode of a power supply system including a power supply circuit according to this embodiment. [Figure 11] It is a flowchart showing the processing procedure for selecting an operation mode in a power supply system including a power supply circuit according to this embodiment. [Figure 12] It is a flowchart showing a modified example of the processing procedure for selecting an operation mode in a power supply system including a power supply circuit according to this embodiment. [Figure 13] It is a schematic diagram showing a modified example of a power supply system including a power supply circuit according to this embodiment. [Figure 14] It is a schematic diagram showing another modified example of a power supply system including a power supply circuit according to this embodiment.

Embodiments for Carrying Out the Invention

[0022] This embodiment will be described in detail with reference to the drawings. For the same or corresponding parts in the drawings, the same reference numerals are given and their descriptions will not be repeated.

[0023] [A. Overall Configuration Example] First, an example of the overall configuration of an electronic device including a power supply circuit according to this embodiment will be described. The power supply circuit according to this embodiment can be applied to any electronic device such as a game console, smartphone, tablet, or personal computer. As an example, the power supply circuit according to this embodiment may be used in a game console as described later.

[0024] Figure 1 is a schematic diagram showing an example of the overall configuration of an electronic device 100 including a power supply circuit according to this embodiment. Referring to Figure 1, the game system 1 includes an electronic device 100, which is an example of an electronic device, and one or more controllers 200.

[0025] The electronic device 100 executes applications such as games according to data indicating user operations from each of the controllers 200. The electronic device 100 has an integrated monitor 106 that outputs arbitrary images.

[0026] Each of the controllers 200 accepts user input. The controllers 200 may be mounted on the electronic device 100. When the controllers 200 are separated from the electronic device 100, data is exchanged between the electronic device 100 and the controllers 200 via wireless communication. When the controllers 200 are mounted on the electronic device 100, data is exchanged between the electronic device 100 and the controllers 200 via wired communication and / or wireless communication.

[0027] [B. Usage of Electronic Device 100] Next, an example of how to use the electronic device 100, which includes a power supply circuit according to this embodiment, will be described.

[0028] In this specification, the mode of use in which the electronic device 100 operates solely on power supplied from the battery installed in the device is referred to as "portable mode," and the mode of use in which the device operates on power supplied from an external power source is referred to as "external power supply mode."

[0029] Figure 2 is a schematic diagram showing an example of using an electronic device 100, including a power supply circuit according to this embodiment, in portable mode. Referring to Figure 2, as an example of portable mode, a user can use the electronic device 100 by grasping the electronic device 100 with a pair of controllers 200 attached.

[0030] As another example of portable mode, the controller 200 may be removed, and the electronic device 100 may be mounted so that the user can view the monitor 106, allowing one or more users to operate the controller 200 while viewing the image output to the monitor 106.

[0031] Figure 3 is a schematic diagram showing an example of using an electronic device 100, including a power supply circuit according to this embodiment, in an external power supply mode. Referring to Figure 3, with the electronic device 100 placed on the dock 350, one or more users operate the controller 200 while viewing the image output to the external monitor 300.

[0032] As an example of an external power supply mode, the electronic device 100 is powered by an external power supply via the dock 350, and also supplies signals for outputting images to the external monitor 300 via the dock 350.

[0033] As shown in Figures 2 and 3, the electronic device 100 (processing circuit 50, described later) can output images to an integrated monitor 106 and an external monitor 300 located outside the electronic device 100.

[0034] In the external power supply mode, the electronic device 100 may receive power directly from any device (such as a power adapter) without going through the dock 350.

[0035] [C. Example of internal configuration of electronic device 100] Next, an example of the internal configuration of an electronic device 100 including a power supply circuit according to this embodiment will be described.

[0036] Figure 4 is a schematic diagram showing an example of the internal configuration of an electronic device 100 including a power supply circuit according to this embodiment. Referring to Figure 4, the electronic device 100 includes a power supply circuit 10, a battery 20, a connector 30, and a processing circuit 50.

[0037] The power supply circuit 10 charges the battery 20 and supplies power to the load circuit. More specifically, the power supply circuit 10 can supply some or all of the power supplied via the connector 30 to the processing circuit 50, which is the load circuit, and can also charge the battery 20 with some or all of the power supplied via the connector 30. A more detailed configuration of the power supply circuit 10 will be described later.

[0038] In the following explanation, the processing circuit 50 is given as an example of a load circuit to which the power supply circuit 10 supplies power. However, the load circuit may be a circuit other than the processing circuit 50, or the entire circuit including the processing circuit 50 may be considered the load circuit.

[0039] For example, each of the controllers 200 has a battery (not shown), and while the controllers 200 are attached to the electronic device 100, power may be supplied from the electronic device 100 to charge the batteries of the controllers 200. In this case, the batteries of the controllers 200 and the circuit for charging the batteries can become the load circuit.

[0040] Battery 20 is a secondary battery that stores power supplied from the power circuit 10 and discharges the stored power. Any secondary battery can be used as battery 20, such as a lithium-ion battery, nickel-metal hydride battery, or nickel-cadmium battery.

[0041] Connector 30 is connected to a dock 350 or a power adapter (not shown). For example, the power adapter performs AC / DC conversion, converting the AC power supplied from an external source into DC power, which is then supplied to the electronic device 100.

[0042] Figure 4 shows an example of connection to the connector 360 of the dock 350. Connector 30 is an interface for receiving power supplied from an external source, and also an interface for electronic device 100 to communicate with external devices. Connector 30 can be, for example, a USB Type-C connector that supports USB PD (USB Power Delivery).

[0043] Figure 4 illustrates a connector 30 that serves as both an interface for receiving power supplied from an external source and an interface for communicating with an external device; however, these interfaces may be provided separately. Furthermore, multiple interfaces for receiving power supplied from an external source may be provided.

[0044] The processing circuit 50 is powered by power supplied from the power supply circuit 10. The processing circuit 50 includes a processor 102, memory 104, storage 120, monitor 106, speaker 108, microphone 110, wireless communication module 112, wired communication module 114, communication controller 116, and power management unit 118.

[0045] The processor 102 is the processing unit for executing the processing provided by the electronic device 100. The memory 104 is a storage device accessible by the processor 102, and is a volatile storage device such as DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory). The storage 120 is a non-volatile storage device such as flash memory.

[0046] The processor 102 reads the program stored in the storage 120, expands it into the memory 104, and executes it, thereby performing the processing described later. The storage 120 stores, for example, a system program 122 that provides libraries necessary for program execution, an application program 124 consisting of instruction codes for realizing arbitrary information processing, and application data 126 that is referenced when the application program 124 is executed.

[0047] In this specification, the term "processor" encompasses not only the usual meaning of a processing circuit that executes processing according to instruction codes written in a program, such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), and GPU (Graphics Processing Unit), but also hardwired circuits such as ASICs (Application Specific Integrated Circuits) and FPGAs (Field Programmable Gate Arrays). Hardwired circuits such as ASICs and FPGAs have circuits pre-formed to correspond to the processing to be executed. Furthermore, the term "processor" in this specification also encompasses circuits that integrate multiple functions, such as SoCs (System on Chip), and also includes combinations of processors in the narrow sense and hardwired circuits.

[0048] The monitor 106 displays an image based on the processing results of the processor 102. The speaker 108 generates arbitrary sounds around the electronic device 100. The microphone 110 collects sounds occurring around the electronic device 100.

[0049] The wireless communication module 112 transmits and receives wireless signals to and from any device. For example, when transmitting and receiving wireless signals to and from a user-operated device 1 or controller 200, the wireless communication module 112 can employ any wireless method, such as Bluetooth®, ZigBee®, Wi-Fi (IEEE802.11), or infrared communication.

[0050] Furthermore, when transmitting and receiving wireless signals with a wireless repeater connected to the internet, the wireless communication module 112 can employ any wireless method, such as wireless LAN (IEEE802.11) or public wireless network (4G or 5G).

[0051] The communication controller 116 communicates with external devices such as the dock 350, which is connected via the connector 30.

[0052] The wired communication module 114 exchanges wired signals with one or more controllers 200 that are mounted on the electronic device 100 when the controllers 200 are mounted on the electronic device 100.

[0053] The power management unit 118 works in conjunction with the communication controller 116 to issue control commands to the power supply circuit 10. The communication controller 116 may also detect the voltage supplied via the connector 30 and provide the detected voltage information to the power management unit 118. Furthermore, the power management unit 118 may be configured to determine whether or not power is being supplied from an external power source. Mode selection and control command generation by the power management unit 118 will be described later.

[0054] [D. Example configuration of a power supply system including a power supply circuit] Next, an example configuration of a power supply system 2 including a power supply circuit 10 according to this embodiment will be described.

[0055] Figure 5 is a schematic diagram showing an example configuration of a power supply system 2 including a power supply circuit 10 according to this embodiment. Referring to Figure 5, the power supply circuit 10 includes a first DC / DC converter 17 connected to an external power supply via a conductive path 11, a charging control circuit 18 connected to an external power supply via a conductive path 13 branched from the conductive path 11, and a conductive path 12 on the output side of the first DC / DC converter 17 and a conductive path 14 on the output side of the charging control circuit 18, and a connected switch circuit 19.

[0056] The charging control circuit 18 is connected to the battery 20 via a conductive path 16. In other words, the power supply circuit 10 has a conductive path 16 that connects the battery 20 and the charging control circuit 18.

[0057] The output side of the switch circuit 19 is connected to the processing circuit 50 via the conductive path 15.

[0058] The first DC / DC converter 17 converts power (DC voltage V1) supplied from an external power source into power of a predetermined voltage (DC voltage V2), and supplies this predetermined voltage power to the processing circuit 50. Power from the external power source is supplied to the first DC / DC converter 17 via the conductive path 11.

[0059] The charging control circuit 18 is connected in parallel with the first DC / DC converter 17 to the external power supply, converts the power (DC voltage V1) supplied from the external power supply into power of a predetermined voltage (DC voltage V3), and supplies this power of the predetermined voltage to the battery 20.

[0060] More specifically, the charging control circuit 18 includes a second DC / DC converter 180 and a current regulator 182 connected to the output side of the second DC / DC converter 180 via a conductive path 184. The second DC / DC converter 180 converts the power supplied via the conductive path 13 into a predetermined voltage. The current regulator 182 adjusts the current values ​​of the power used to charge the battery 20 and the power used to discharge the battery 20.

[0061] The charging control circuit 18 uses sensors (not shown) to estimate the charging state of the battery 20 from its voltage, current, temperature, etc., and charges the battery 20 with a voltage and current appropriate to the estimated charging state.

[0062] The first DC / DC converter 17 has a relatively higher conversion efficiency compared to the second DC / DC converter 180 of the charging control circuit 18. In other words, the conversion efficiency of the first DC / DC converter 17 in converting power supplied from an external power source (DC voltage V1) to power of a predetermined voltage (DC voltage V2) is higher than the conversion efficiency of the charging control circuit 18 in converting power supplied from an external power source (DC voltage V1) to power of a predetermined voltage (DC voltage V3).

[0063] The conversion efficiency refers to the ratio of output power to input power to the first DC / DC converter 17 and the second DC / DC converter 180, respectively. Generally, the conversion efficiency η = output power [W] / input power [W] = (output current value × output voltage value) / (input current value × input voltage value).

[0064] In this embodiment, as an example, the operating voltage range permitted by the first DC / DC converter 17 (e.g., 8 to 12 [V]) is narrower than the operating voltage range permitted by the second DC / DC converter 180 (e.g., 3 to 12 [V]). However, the first DC / DC converter 17 is designed to have higher conversion efficiency within its permitted operating voltage range.

[0065] The first DC / DC converter 17 has a higher voltage conversion efficiency than the second DC / DC converter 180 within a predetermined DC voltage range. The voltage conversion efficiency of the first DC / DC converter 17 within a predetermined DC voltage range may be higher than the voltage conversion efficiency outside that predetermined DC voltage range.

[0066] The switch circuit 19 includes an input section 190 connected to the conductive path 12, an input section 192 connected to the conductive path 14, an output section 194 connected to the conductive path 15, and a switch 196 for connecting either the input section 190 or the input section 192 to the output section 194.

[0067] Thus, the power supply circuit 10 includes a conductive path 12 connecting the output side of the first DC / DC converter 17 to the input section 190 of the switch circuit 19, a conductive path 14 connecting the output side of the charging control circuit 18 to the input section 192 of the switch circuit 19, and a conductive path 15 connecting the output section 194 of the switch circuit 19 to the processing circuit 50. The switch circuit 19 also includes a switch 196 that connects either the conductive path 12 or the conductive path 14 to the conductive path 15.

[0068] The switch circuit 19 includes a diode 198, which is an example of a rectifier element placed between the conductive path 14 and the conductive path 15. The diode 198 allows current to pass from the conductive path 14 to the conductive path 15 and blocks current from the conductive path 15 to the conductive path 14. In other words, the switch circuit 19 includes a rectifier element (diode 198) placed between the conductive path 14 and the conductive path 15 that allows current to pass from the conductive path 14 to the conductive path 15.

[0069] The first DC / DC converter 17, the charging control circuit 18, and the switch circuit 19 operate according to control commands from the power management unit 118. For example, the power management unit 118 issues control commands to the switch circuit 19 based on the power supplied from an external power source.

[0070] [Example configuration of E. Dock] Next, an example configuration of the dock 350 according to this embodiment will be described.

[0071] Figure 6 is a schematic diagram showing an example configuration of a dock 350 according to this embodiment. The dock 350 is an example of an auxiliary device that supplies DC voltage V1 power. The auxiliary device holds the electronic device 100 and outputs video data from the electronic device 100 to external video display devices (especially stationary video display devices) such as television receivers, video monitors, and projectors via a video cable. The external video display device will be referred to as the external monitor 300 below. Furthermore, the auxiliary device according to this embodiment supplies power to the electronic device it holds via an external power cable connected to the auxiliary device.

[0072] Referring to Figure 6, the dock 350 includes a regulator 352, a communication controller 354, and an external monitor interface 356.

[0073] The regulator 352 supplies power to the electronic device 100 via the connector 360. The communication controller 354 communicates with the communication controller 116 of the electronic device 100 via the connector 360.

[0074] The external monitor interface 356 supplies signals for outputting an image to the external monitor 300 based on signals received via the communication controller 354.

[0075] The external power supplied to Dock 350 may be DC power or AC power.

[0076] Furthermore, the regulator 352 may be configured to adjust the voltage of the power supplied from an external power source. In this case, the voltage adjustment by the regulator 352 may be performed in conjunction with the communication controller 354. If AC power is supplied to the dock 350, the regulator 352 may include an AC / DC converter (or a rectifier circuit).

[0077] [F. Power System Operating Modes] Next, the operating modes of the power supply system 2, which includes the power supply circuit 10 according to this embodiment, will be described.

[0078] (f1: First mode) The first mode of the power supply system 2 is selected when power is supplied from an external power source. In the first mode, power is supplied to the processing circuit 50 from the first DC / DC converter 17.

[0079] Figure 7 is a diagram illustrating the operation of the power supply system 2 in a first mode, including the power supply circuit 10 according to this embodiment.

[0080] Referring to Figure 7, in the first mode, the first DC / DC converter 17 supplies power to the processing circuit 50. More specifically, the DC voltage V1 supplied from the external power supply is supplied to the first DC / DC converter 17 via the conductive path 11. The first DC / DC converter 17 converts (steps down) the DC voltage V1 to DC voltage V2. Also, the switch 196 of the switch circuit 19 is maintained in a state where the input section 190 and the output section 194 are connected. As a result, the DC voltage V2 is supplied to the processing circuit 50 via the conductive path 12, the switch circuit 19, and the conductive path 15.

[0081] Furthermore, depending on the charge state of the battery 20, the battery 20 may be charged using a portion of the power supplied from an external power source. That is, in the first mode, the power (DC voltage V3) converted by the charging control circuit 18 is supplied to the battery 20.

[0082] More specifically, the DC voltage V1 power supplied from the external power source is supplied to the second DC / DC converter 180 of the charging control circuit 18 via the conductive path 13. The second DC / DC converter 180 converts (steps down) the DC voltage V1 to DC voltage V3. As a result, the DC voltage V3 power is supplied to the battery 20 via the conductive path 184, the current regulator 182, and the conductive path 16.

[0083] For example, DC voltage V1 may be set to approximately 10[V]. DC voltage V2 may be set to approximately 6[V]. DC voltage V3 may be set to approximately 2.9[V] to 4.4[V].

[0084] (f2: second mode) The second mode of the power supply system 2 is selected when power is not supplied from an external power source. In the second mode, power is supplied to the processing circuit 50 from the battery 20.

[0085] Figure 8 is a diagram illustrating the operation of the power supply system 2 in a second mode, including the power supply circuit 10 according to this embodiment.

[0086] Referring to Figure 8, in the second mode, the battery 20 supplies power to the processing circuit 50. More specifically, the current regulator 182 of the charge control circuit 18 operates to discharge the battery 20. Also, the switch 196 of the switch circuit 19 is maintained in a state where the input section 192 and the output section 194 are connected. As a result, the DC voltage V4 power discharged by the battery 20 is supplied to the processing circuit 50 via the conductive path 12, the switch circuit 19, and the conductive path 15.

[0087] Note that the magnitude of the DC voltage V4 may vary depending on the charge state of the battery 20. For example, the DC voltage V4 will be approximately 3.0 to 4.5 [V].

[0088] (f3: Third mode) The third mode of the power supply system 2 is selected when power is supplied from an external power source. In the third mode, the charging control circuit 18 supplies at least a portion of the DC voltage V3 power to the processing circuit 50.

[0089] Figure 9 is a diagram illustrating the operation of the power supply system 2 in a third mode, including the power supply circuit 10 according to this embodiment.

[0090] Referring to Figure 9, in the third mode, the second DC / DC converter 180 of the charging control circuit 18 supplies power to the processing circuit 50. More specifically, the DC voltage V1 supplied from the external power supply is supplied to the second DC / DC converter 180 via the conductive path 13. The second DC / DC converter 180 converts (steps down) the DC voltage V1 to a DC voltage V3. Also, the switch 196 of the switch circuit 19 is maintained in a state where the input section 192 and the output section 194 are connected. As a result, the DC voltage V3 is supplied to the processing circuit 50 via the conductive path 14, the switch circuit 19, and the conductive path 15.

[0091] Furthermore, depending on the charge state of the battery 20, the battery 20 may be charged using a portion of the power supplied from an external power source. More specifically, a portion of the power of the DC voltage V3 output by the second DC / DC converter 180 is supplied to the battery 20 via the conductive path 184, the current regulator 182, and the conductive path 16.

[0092] (f4: 4th mode) The fourth mode of the power supply system 2 is selected when power is supplied from an external power source. In the fourth mode, both the first DC / DC converter 17 and the charging control circuit 18 supply power to the processing circuit 50.

[0093] Figure 10 is a diagram illustrating the operation of the power supply system 2 in a fourth mode, including the power supply circuit 10 according to this embodiment.

[0094] Referring to Figure 10, in the fourth mode, the first DC / DC converter 17 and the second DC / DC converter 180 of the charging control circuit 18 supply power to the processing circuit 50.

[0095] More specifically, a portion of the power from the DC voltage V1 supplied from the external power supply is supplied to the first DC / DC converter 17 via the conductive path 11. The first DC / DC converter 17 converts (steps down) the DC voltage V1 to DC voltage V2. Also, the switch 196 of the switch circuit 19 is maintained in a state where the input section 190 and the output section 194 are connected. As a result, the power from the DC voltage V2 is supplied to the processing circuit 50 via the conductive path 12, the switch circuit 19, and the conductive path 15.

[0096] In parallel with the power supply by the first DC / DC converter 17, the remaining power of the DC voltage V1 supplied from the external power supply is supplied to the second DC / DC converter 180 via the conductive path 13. The second DC / DC converter 180 converts (steps down) the DC voltage V1 to a DC voltage V3. The power of the DC voltage V3 is supplied to the processing circuit 50 via the conductive path 14, diode 198, and conductive path 15.

[0097] In the fourth mode, since the first DC / DC converter 17 and the second DC / DC converter 180 supply power to the processing circuit 50 in parallel, it is ideal that the DC voltages appearing on the output side of the switch circuit 19 are substantially the same. For this reason, the DC voltage V3 output by the second DC / DC converter 180 may be adjusted to be higher than the DC voltage V2 output by the first DC / DC converter 17 by the amount of the forward voltage of the diode 198.

[0098] [G. Selecting the operating mode of the power system] Next, the selection of an operating mode in the power supply system 2, which includes the power supply circuit 10 according to this embodiment, will be described.

[0099] (g1: Operation mode selection process part 1) Figure 11 is a flowchart showing the process for selecting an operating mode in a power supply system 2 including a power supply circuit 10 according to this embodiment.

[0100] Referring to Figure 11, the power management unit 118 of the electronic device 100 determines whether or not power is being supplied from an external power source (step S100).

[0101] For example, the voltage supplied via connector 30 may be detected to determine whether or not power is being supplied from an external power source. Alternatively, if a configuration is adopted in which power is supplied from dock 350 or power adapter according to USB PD, the communication controller 116 determines the DC voltage of the power to be supplied through negotiation. Therefore, the power management unit 118 can also determine whether or not power is being supplied from an external power source and the DC voltage of the supplied power based on information from the communication controller 116.

[0102] If power is not supplied from an external power source (NO in step S100), the power management unit 118 selects the second mode (step S102) and issues a control command to the charging control circuit 18 to supply power from the battery 20 to the processing circuit 50 (step S104).

[0103] Then, until power is supplied from an external power source (NO in step S106), the battery 20 continues to supply power to the processing circuit 50. When power is supplied from an external power source (YES in step S106), the process from step S100 onward is repeated.

[0104] If power is supplied from an external power source (YES in step S100), the power management unit 118 determines whether the DC voltage V1 of the power supplied from the external power source is within a predetermined DC voltage range (step S108). For example, the predetermined DC voltage range is set to correspond to the operating voltage range that the first DC / DC converter 17 allows. In this case, the power management unit 118 determines whether the power supplied from the external power source can be input to the first DC / DC converter 17.

[0105] If the DC voltage V1 of the power supplied from the external power source is within a predetermined DC voltage range (YES in step S108), the power management unit 118 selects the first mode (step S110) and issues a control command to the first DC / DC converter 17 to supply power from the first DC / DC converter 17 to the processing circuit 50 (step S112).

[0106] Furthermore, the charging control circuit 18 determines whether the conditions for charging the battery 20 are met (step S114). If the conditions for charging the battery 20 are met (YES in step S114), the charging control circuit 18 supplies power output by the second DC / DC converter 180 to the battery 20 (step S116).

[0107] If the conditions for charging the battery 20 are not met (NO in step S114), the process in step S116 is skipped.

[0108] Then, the state in which the second DC / DC converter 180 supplies power to the processing circuit 50 is maintained until the power supply from the external power source is stopped, or until the DC voltage V1 of the power supplied from the external power source falls outside the predetermined DC voltage range (NO in step S118). When the power supply from the external power source is stopped, or until the DC voltage V1 of the power supplied from the external power source falls outside the predetermined DC voltage range (YES in step S118), the process from step S100 onward is repeated.

[0109] On the other hand, if the DC voltage V1 of the power supplied from the external power source is not within a predetermined DC voltage range (NO in step S108), the power management unit 118 selects the third mode (step S120) and issues a control command to the charging control circuit 18 to supply power from the second DC / DC converter 180 to the processing circuit 50 (step S122).

[0110] The charging control circuit 18 determines whether the conditions for charging the battery 20 are met (step S124). If the conditions for charging the battery 20 are met (YES in step S124), the charging control circuit 18 supplies a portion of the power output by the second DC / DC converter 180 to the battery 20 (step S126).

[0111] If the condition for charging battery 20 is not met (NO in step S124), the process in step S126 is skipped.

[0112] Then, the state in which the second DC / DC converter 180 supplies power to the processing circuit 50 is maintained until the power supply from the external power source is stopped, or until the DC voltage V1 of the power supplied from the external power source falls within a predetermined DC voltage range (NO in step S128). When the power supply from the external power source is stopped, or until the DC voltage V1 of the power supplied from the external power source falls within a predetermined DC voltage range (YES in step S128), the process from step S100 onward is repeated.

[0113] As described above, when power is supplied from an external power source, the first mode may be selected if the DC voltage V1 of the power supplied from the external power source is within a predetermined DC voltage range, and the third mode may be selected if the DC voltage V1 is not within the predetermined DC voltage range.

[0114] (g2: Operation mode selection process part 2) Figure 12 is a flowchart showing a modified version of the procedure for selecting an operating mode in a power supply system 2 including a power supply circuit 10 according to this embodiment. The flowchart in Figure 12 has an additional step S130 compared to the flowchart in Figure 11. Steps similar to those in Figure 11 will not be explained again.

[0115] If the DC voltage V1 of the power supplied from the external power source is within a predetermined DC voltage range (YES in step S108), the power management unit 118 determines the output destination of the image (step S130).

[0116] If an image is output to the external monitor 300 (referred to as "external monitor" in step S130), the power management unit 118 selects the first mode (step S110) and executes the processes from step S112 onwards. If an image is output to the integrated monitor 106 (referred to as "integrated monitor" in step S130), the power management unit 118 selects the second mode (step S120) and executes the processes from step S122 onwards.

[0117] Thus, when the DC voltage V1 of the power supplied from the external power source is within a predetermined DC voltage range, the switch circuit 19 switches to the first mode when an image is output to the external monitor 300, and switches to the third mode when an image is output to the integrated monitor 106.

[0118] For example, if the number of display pixels of the external monitor 300 is higher than the number of display pixels of the integrated monitor 106, the process of generating (drawing) the image to be output to the external monitor 300 will require a higher processing load. Therefore, by supplying power from the first DC / DC converter 17, which has a high conversion efficiency (by selecting the first mode), power loss in the power supply circuit 10 can be reduced.

[0119] On the other hand, when the integrated monitor 106 outputs an image, the processing circuit 50 requires relatively less power, so by supplying power from the second DC / DC converter 180 of the more versatile charging control circuit 18 (by selecting the third mode), the constraints on devices that can be used as an external power source can be reduced. For example, the DC voltage of the power supplied by the dock 350 matches the operating voltage range allowed by the first DC / DC converter 17, but the operating voltage range of the first DC / DC converter 17 is narrower than the operating voltage range of the second DC / DC converter 180. Therefore, if power is supplied to the electronic device 100 from a power adapter other than the dock 350, it is conceivable that the DC voltage of the power supplied by that power adapter may not match the operating voltage range allowed by the first DC / DC converter 17.

[0120] Therefore, when power is supplied from a device other than the dock 350 (a power adapter), the versatility of the external power supply can be increased by using the second DC / DC converter 180 of the charging control circuit 18, which has a wider operating voltage range.

[0121] Furthermore, since the output of images to the external monitor 300 is based on the assumption that it is mounted on the dock 350, if an image is output to the integrated monitor 106 while power is supplied from an external power source, it can be inferred that power is being supplied from a device other than the dock 350.

[0122] (g3: Operation mode selection process part 3) For example, if more power needs to be supplied to the processing circuit 50 while the first mode is selected, the system may switch to the fourth mode. The fourth mode supplies power from the second DC / DC converter 180 to the processing circuit 50 in addition to the power from the first DC / DC converter 17, for example, when the power supply to the load circuit is insufficient with the first mode alone. By providing the fourth mode, even when the load on the processing circuit 50 is large, power can be stably supplied to the processing circuit 50, allowing processing to continue in the processing circuit 50.

[0123] Situations requiring even more power include, for example, when a computationally intensive application is running or when the controller 200's battery is being charged. The system may also determine whether or not to switch to the fourth mode based on the amount of power output by the first DC / DC converter 17 and information from the system program running in the processing circuit 50.

[0124] [H. Variant] The power supply circuit and power supply system including the power supply circuit according to this embodiment may be modified in any way as follows.

[0125] (h1: Obtaining the DC voltage of power supplied from an external power source) In the above-described embodiment, as an example, a configuration was shown in which the DC voltage of the power supplied is obtained by negotiation with the dock 350 or power adapter (according to USB PD), but the system is not limited to this, and any method can be adopted.

[0126] For example, the dock 350 or power adapter may notify the power supply circuit 10 of the DC voltage. Alternatively, the power supply circuit 10 may instruct the dock 350 or power supply adapter to provide the DC voltage.

[0127] Alternatively, the DC voltage of the power supplied from an external power source may be measured. Figure 13 is a schematic diagram showing a modified example of the power supply system 2, which includes a power supply circuit 10 according to this embodiment. Referring to Figure 13, the power supply circuit 10 includes a voltage divider resistor 40 connected between the conductive path 11 and ground. The power management unit 118 includes a measurement circuit 1180 for measuring the voltage generated across the voltage divider resistor 40. Based on the measurement results of the measurement circuit 1180, the DC voltage of the power supplied from an external power supply can be obtained. The measurement circuit 1180 may be located in any position.

[0128] (h2:Power management section) In the above-described embodiment, a configuration in which a power management unit 118 is provided separately from the power supply circuit 10 was illustrated, but the power management unit 118 may also be configured as part of the power supply circuit 10. In this case, the communication controller 116 may also be configured as part of the power supply circuit 10.

[0129] Furthermore, a function equivalent to the power management unit 118 may be placed in a dock 350, which is an example of auxiliary equipment. In this case, the communication controller 116 receives control commands from the power management unit 118 located in the dock 350, and the communication controller 116 provides control commands to the first DC / DC converter 17, the charging control circuit 18, and the switch circuit 19.

[0130] By placing the functions equivalent to the power management unit 118 in the dock 350, the number of components required for the electronic device 100, including the power supply circuit 10, can be reduced, thereby making the electronic device 100 smaller and lighter.

[0131] Thus, the power management unit 118 may be located outside the power supply circuit 10 or inside the power supply circuit 10. Regardless of the location of the power management unit 118, the power supply circuit 10 and the power management unit 118 can be collectively referred to as the power supply system 2.

[0132] (h3: Bypass switch) In the above-described embodiment, a configuration was illustrated in which the first DC / DC converter 17 and the charging control circuit 18 are each connected to an external power supply. However, power may also be supplied to the first DC / DC converter 17 from an external power supply via the charging control circuit 18.

[0133] Figure 14 is a schematic diagram showing another modification of the power supply system 2, which includes a power supply circuit 10 according to this embodiment. Referring to Figure 14, the charging control circuit 18 includes a switch 186 located in a conductive path 11 that connects an external power supply to the first DC / DC converter 17.

[0134] The charging control circuit 18 drives switch 186 to the ON position in the first mode and / or fourth mode. This supplies power from an external power source to the first DC / DC converter 17. By providing switch 186, the power supply to the first DC / DC converter 17 can be cut off in the third mode.

[0135] (h4: Processing when power is supplied from an external power source other than the Dock 350) In the above-described embodiment, as an example, a configuration was shown in which the DC voltage of the power supplied is obtained by negotiation (according to USB PD) with the dock 350 or a power adapter. During negotiation, identification information for identifying the external power source may be obtained. Therefore, it is possible to determine whether the dock 350 is connected as the external power source or whether another device (such as a power adapter) is connected.

[0136] Therefore, the power management unit 118 may select the first mode only when connected to the dock 350. In this case, if power is supplied from an external power source other than the dock 350, the third mode may be selected. In the third mode, the second DC / DC converter 180, which has a wide allowable operating voltage range, supplies power, so even if the DC voltage of the power supplied from the external power source fluctuates, the impact on the power supply to the processing circuit 50 can be suppressed.

[0137] (h5: Mode 1) In the above-described embodiment, an example of a process in which the first mode is selected if the DC voltage V1 of the power supplied from an external power source is within a predetermined DC voltage range was explained. However, in addition to the condition of the DC voltage V1 of the power supplied from an external power source, the condition that the electronic device 100 is mounted on the dock 350 may be added as a condition for selecting the first mode. That is, the first mode may be selected if the DC voltage V1 of the power supplied from an external power source is within a predetermined DC voltage range AND the electronic device 100 is mounted on the dock 350.

[0138] Any method may be used by the electronic device 100 to determine whether it is docked in the dock 350. For example, it may determine whether it is docked in the dock 350 based on whether or not it can receive predetermined identification information from the dock 350.

[0139] [I. Advantages] According to this embodiment, the conversion efficiency of voltage conversion can be improved in a power supply circuit that charges a battery and supplies power to a load circuit.

[0140] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope of the claims are intended to be included. [Explanation of Symbols]

[0141] 1 Game System, 2 Power System, 10 Power Circuit, 11, 12, 13, 14, 15, 16, 184 Conductive Path, 17 First DC / DC Converter, 18 Charging Control Circuit, 19 Switch Circuit, 20 Battery, 30, 360 Connector, 40 Voltage Divider Resistor, 50 Processing Circuit, 100 Electronic Devices, 102 Processor, 104 Memory, 106 Monitor, 108 Speaker, 110 Microphone, 112 Wireless Communication Module, 114 Wired Communication Module, 116, 354 Communication Controller, 118 Power Management Unit, 120 Storage, 122 System Program, 124 Application Program, 126 Application Data, 180 Second DC / DC Converter, 182 Current Regulator, 186, 196 Switch, 190, 192 Input Unit, 194 Output Unit, 198 Diode, 200 Controller, 300 External monitor, 350 dock, 352 regulator, 356 external monitor interface, 1180 measurement circuit, V1, V2, V3, V4 DC voltage.

Claims

1. A power supply circuit that charges a battery and supplies power to a load circuit, A DC / DC converter that converts power of a first DC voltage supplied from an external power source into power of a second DC voltage, and supplies the power of the second DC voltage to the load circuit, A charging control circuit is connected in parallel with the DC / DC converter to the external power supply, converts the power of the first DC voltage into power of the third DC voltage, and supplies the power of the third DC voltage to the battery. A power supply circuit comprising a switch circuit that switches between a first mode in which power is supplied to the load circuit from the DC / DC converter and a second mode in which power is supplied to the load circuit from the battery without going through the DC / DC converter.

2. The power supply circuit according to claim 1, wherein in a third mode different from the first and second modes, the charging control circuit supplies at least a portion of the power of the third DC voltage to the load circuit.

3. The power supply circuit according to claim 2, wherein in a fourth mode different from the first, second, and third modes, both the DC / DC converter and the charging control circuit supply power to the load circuit.

4. The power supply circuit according to claim 2 or 3, wherein the conversion efficiency of the DC / DC converter in converting the power of the first DC voltage to the power of the second DC voltage is higher than the conversion efficiency of the charging control circuit in converting the power of the first DC voltage to the power of the third DC voltage.

5. If the first DC voltage is within a predetermined DC voltage range, the first mode is selected. The power supply circuit according to any one of claims 2 to 4, wherein the third mode is selected if the first DC voltage is not within the range of the predetermined DC voltage.

6. The load circuit is capable of outputting images to an integrated monitor within the electronic device including the load circuit and to an external monitor located outside the electronic device. When the first DC voltage is within a predetermined DC voltage range and an image is output to the external monitor, the switch circuit switches to the first mode. The power supply circuit according to any one of claims 2 to 4, wherein the switch circuit switches to the third mode when the first DC voltage is within the range of the predetermined DC voltage and an image is output to the integrated monitor.

7. In the first mode, the charging control circuit supplies power of the third DC voltage to the battery, the power supply circuit according to any one of claims 1 to 6.

8. A first conductive path connects the output side of the DC / DC converter to the first input section of the switch circuit, A second conductive path connects the output side of the charging control circuit and the second input section of the switch circuit, The power supply circuit according to any one of claims 1 to 7, further comprising a third conductive path connecting the output section of the switch circuit and the load circuit.

9. The aforementioned switch circuit is A switch connecting either the first conductive path or the second conductive path to the third conductive path, The power supply circuit according to claim 8, further comprising a rectifier element disposed between the second conductive path and the third conductive path, which allows current to pass from the second conductive path to the third conductive path.

10. The system further comprises a fourth conductive path connecting the battery and the charging control circuit, The power supply circuit according to claim 8 or 9, wherein in the second mode, power from the battery is supplied to the load circuit via the second conductive path, the switch circuit, and the third conductive path.

11. A power supply system that charges a battery and supplies power to a load circuit, A DC / DC converter that converts power of a first DC voltage supplied from an external power source into power of a second DC voltage, and supplies the power of the second DC voltage to the load circuit, A charging control circuit is connected in parallel with the DC / DC converter to the external power supply, converts the power of the first DC voltage into power of the third DC voltage, and supplies the power of the third DC voltage to the battery. A switch circuit that switches between a first mode in which power is supplied to the load circuit from the DC / DC converter and a second mode in which power is supplied to the load circuit from the battery without going through the DC / DC converter, A power supply system comprising: a power management unit that gives control commands to the switch circuit based on the power supplied from the external power supply.

12. The power supply system according to claim 11, further comprising auxiliary equipment for supplying power of the first DC voltage.

13. The power supply system according to claim 12, wherein the power supply management unit is provided in the auxiliary equipment.

14. In a third mode different from the first and second modes, the charging control circuit supplies at least a portion of the power of the third DC voltage to the load circuit, the power supply system according to any one of claims 11 to 13.

15. The power supply system according to claim 14, wherein in a fourth mode different from the first, second, and third modes, both the DC / DC converter and the charging control circuit supply power to the load circuit.

16. The power supply system according to claim 14 or 15, wherein the conversion efficiency of the DC / DC converter in converting the power of the first DC voltage to the power of the second DC voltage is higher than the conversion efficiency of the charging control circuit in converting the power of the first DC voltage to the power of the third DC voltage.

17. If the first DC voltage is within a predetermined DC voltage range, the first mode is selected. The power supply system according to any one of claims 14 to 16, wherein the third mode is selected if the first DC voltage is not within a predetermined range of DC voltages.

18. The load circuit is capable of outputting images to an integrated monitor within the electronic device including the load circuit and to an external monitor located outside the electronic device. When the first DC voltage is within a predetermined DC voltage range and an image is output to the external monitor, the switch circuit switches to the first mode. The power supply system according to any one of claims 14 to 16, wherein the switch circuit switches to the third mode when the first DC voltage is within the range of the predetermined DC voltage and an image is output to the integrated monitor.

19. In the first mode, the charging control circuit supplies power of the third DC voltage to the battery, the power supply system according to any one of claims 11 to 18.

20. A first conductive path connects the output side of the DC / DC converter to the first input section of the switch circuit, A second conductive path connects the output side of the charging control circuit and the second input section of the switch circuit, The power supply system according to any one of claims 11 to 19, further comprising a third conductive path connecting the output section of the switch circuit and the load circuit.

21. The aforementioned switch circuit is A switch connecting either the first conductive path or the second conductive path to the third conductive path, The power supply system according to claim 20, further comprising a rectifier element disposed between the second conductive path and the third conductive path, which allows current to pass from the second conductive path to the third conductive path.

22. The system further comprises a fourth conductive path connecting the battery and the charging control circuit, The power supply system according to claim 20 or 21, wherein in the second mode, power from the battery is supplied to the load circuit via the second conductive path, the switch circuit, and the third conductive path.

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