Port Controllers, Electronic Devices

Abstract

To provide a port controller capable of executing initial negotiations in a dead battery state.SOLUTION: A port controller 300 is compatible with the USB (Universal Serial Bus) Type-C standard, and can be used for an apparatus that can operate as a sink device. An interface circuit 330 can communicate with an external main controller 210. A transceiver 320 can communicate with a source device 400 via a CC (Configuration Channel) pin of a receptacle. A control unit 340 can perform negotiations with the source device 400 via the transceiver 320. A pin control circuit 310 controls the state of the CC pin and monitors the state of the CC pin. A power supply circuit receives a bus voltage supplied from the source device 400 and generates a power supply voltage VDD2 for the main controller 210.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a technology for supplying power to electronic devices. [Background technology]

[0002] Battery-powered devices (electronic devices) such as mobile phones, smartphones, tablets, notebook computers, and portable audio players incorporate a charging circuit to charge the rechargeable secondary battery. The charging circuit uses a DC voltage (bus voltage V) supplied from an external device via a USB cable. BUS ) and those that charge secondary batteries based on DC voltage from an external AC adapter.

[0003] The USB Power Delivery standard (hereafter referred to as the USB PD standard) has been established for power supply devices and systems that use USB. The USB PD standard supports power supply up to 100W. The USB PD standard has also been adopted for the USB Type-C standard.

[0004] In USB Type-C, the side that supplies power is called the source, and the side that receives power is called the sink. A device with a source function (source role) is also called a provider or source device, and a device with a sink function (sink role) is also called a consumer or sink device.

[0005] To provide the USB PD and Type-C functions, a port controller integrated circuit (IC) is used to handle control related to USB PD and Type-C.

[0006] The port controller IC provides the physical and logical layer functions of USB-Type-C. The port controller IC has the function of detecting the source device based on the state of the CC (Configuration Channel) port and performing negotiation via the CC pins.

[0007] Port controller ICs are available in two types: those that operate under the control of the electronic device's main controller and those that operate completely standalone.

[0008] The port controller IC, which operates under the control of the main controller, obtains from the main controller information relating to the power required by the electronic device 200. Therefore, when the battery of the electronic device is discharged and the main controller is inoperable, the port controller IC cannot perform initial negotiation (power negotiation). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 6604863 Summary of the Invention [Problem to be solved by the invention]

[0010] In the USB PD standard, a device is considered a sink device by pulling down the CC pin with a pull-down resistor Rd. Therefore, when the battery is completely discharged (dead battery state), by waiting with the CC pin pulled down, it can receive power when a source device is connected and start up from the dead battery state.

[0011] Here, the sink device has a bus switch on the line from the VBUS pin to the internal circuit. While this bus switch is off, the bus voltage V BUS is not supplied to the internal circuit. In other words, the internal main controller does not start, and the port controller cannot obtain the initial information required for the initial negotiation.

[0012] The present disclosure has been made in this situation, and one exemplary purpose of an aspect thereof is to provide a port controller that can execute initial negotiation in a dead battery state. [Means for solving the problem]

[0013] An aspect of the present disclosure relates to a port controller that is compatible with the USB (Universal Serial Bus) Type-C standard and can be used in an apparatus that can operate as a sink device. The port controller includes an interface circuit that can communicate with an external main controller, a transceiver that can communicate with a source device via a CC (Configuration Channel) pin, a control unit that can negotiate with the source device via the transceiver, a pin control circuit that controls and monitors the state of the CC pin, and a power supply circuit that receives a bus voltage supplied from the source device and generates a power supply voltage for the main controller.

[0014] Any combination of the above components or conversion of the present disclosure into methods, devices, etc. are also valid aspects of the present invention. [Effects of the Invention]

[0015] Certain aspects of the present disclosure allow for dead battery operation. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a block diagram of an electronic device including a port controller according to an embodiment. [Figure 2] FIG. 2 is a block diagram of a port controller according to an embodiment. [Figure 3] 3 is a time chart showing the operation of the port controller of FIG. 2; [Figure 4] 10 is a time chart showing the operation of a port controller according to a comparative technique. DETAILED DESCRIPTION OF THE INVENTION

[0017] (Outline of the embodiment) A summary of some exemplary embodiments of the present disclosure is provided. This summary is intended to provide a simplified overview of some concepts of one or more embodiments in order to provide a basic understanding of the embodiments as a prelude to the more detailed description that follows. It is not intended to limit the scope of the invention or disclosure. This summary is not an exhaustive overview of all possible embodiments, and is not intended to identify key elements of all embodiments or to delineate the scope of some or all aspects. For convenience, the term "one embodiment" may refer to one embodiment (example or variant) or multiple embodiments (examples or variants) disclosed herein.

[0018] A port controller according to one embodiment is compatible with the USB Type-C standard and can be used in devices that can operate as sink devices. The port controller includes an interface circuit that can communicate with an external main controller, a transceiver that can communicate with a source device via a configuration channel (CC) pin, a pin control circuit that controls and monitors the state of the CC pin, and a power supply circuit that receives a bus voltage supplied from the source device and generates a power supply voltage for the main controller.

[0019] In the dead battery state, even if the bus switch is off, the main controller is supplied with the power supply voltage generated by the power supply circuit of the port controller, and the main controller can be started up. After the main controller is started up, the port controller can receive information necessary for negotiation from the main controller and perform initial negotiation with the other device (source device).

[0020] In one embodiment, the port controller may further include a switch driver that controls a bus switch connected to the VBUS pin of the receptacle. The switch driver may turn on the bus switch in response to an instruction from the main controller. The bus voltage V BUS After the power supply is supplied, the main controller instructs the port controller to turn on the bus switch, provided that the internal circuitry is normal, thereby enabling the system to operate safely.

[0021] In one embodiment, the port controller may further include a switch driver that controls a bus switch connected to a VBUS pin of the receptacle. After the initial negotiation is completed, the control unit may instruct the switch driver to turn on the bus switch. In this case, the system can be operated safely by having the main controller instruct the start of the initial negotiation, provided that the internal circuitry is normal.

[0022] (Embodiment) Preferred embodiments will be described below with reference to the drawings. The same or equivalent components, parts, and processes shown in each drawing will be given the same reference numerals, and redundant explanations will be omitted where appropriate. Furthermore, the embodiments are examples and do not limit the disclosure and invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the disclosure and invention.

[0023] In this specification, "a state in which component A is connected to component B" includes not only a case in which component A and component B are directly physically connected to each other, but also a case in which component A and component B are indirectly connected to each other via other components that do not substantially affect the electrical connection between them or that do not impair the function or effect achieved by their connection.

[0024] Similarly, "a state in which component C is connected (provided) between component A and component B" includes not only a case in which component A and component C, or component B and component C, are directly connected, but also a case in which they are indirectly connected via other components that do not substantially affect the electrical connection state between them or that do not impair the function or effect achieved by their combination.

[0025] 1 is a block diagram of electronic device 200 including port controller 300 according to an embodiment. Electronic device 200 includes port controller 300, receptacle 202, bus switch 204, main controller 210, main power supply 220, and battery 222. Note that electronic device 200 may include blocks in accordance with its specific functions in addition to the blocks shown here.

[0026] A source device (also referred to as a counterpart device) 400 can be connected to a receptacle 202 of the electronic device 200 via a USB cable 402. The electronic device 200 can be a consumer in the USB Type-C standard, and can be powered by the source device 400. The main power supply 220 can include a charging circuit that charges a battery 222 with power from the source device 400.

[0027] The receptacle 202 includes a VBUS pin, a CC1 pin, a CC2 pin, and a GND pin. A source device 400 is connected to the receptacle 202 via a USB cable 402.

[0028] The bus switch 204 is inserted between the VBUS pin and the main power supply 220. When the initial negotiation between the electronic device 200 and the counterpart device 400 is completed, the bus switch 204 is turned on, and the bus voltage V BUS For example, the port controller 300 responds to an instruction from the main controller 210 to switch the bus switch 204 on and off.

[0029] The main controller 210 includes a processor that controls the electronic device 200 in an integrated manner, and is configured, for example, by a microcontroller or a SoC (System on Chip).

[0030] The port controller 300 is a functional IC (Integrated Circuit) equipped with a power supply pin VDD, CC pins CC1 and CC2, a ground pin GND, a switch control pin SWCNT, and an interface pin IF. The power supply pin VDD, ground pin GND, CC1 pin, and CC2 pin are connected to corresponding pins of the receptacle. The interface pin IF is connected to the main controller 210. The SWCNT pin is connected to the control terminal of the bus switch 204.

[0031] The port controller 300 is equipped with a physical layer and a logical layer (protocol) required for communication with the counterpart device 400. The port controller 300 negotiates with the counterpart device 400 based on information received from the main controller 210. This information includes required power specific to the electronic device 200, etc.

[0032] The port controller 300 also has a power output pin VOUT. The power output pin VOUT outputs a power supply voltage V DD2 When the main power supply 220 is operating, the main controller 210 outputs the power supply voltage V DD1 When the main power supply 220 is not operating, the port controller 300 generates a power supply voltage V DD2 The power supply terminal of the main controller 210 can be connected to two power supply voltages V DD1 ,V DD2 can be supplied, or a selector (switch) can be used to select between two power supply voltages V DD1 ,V DD2 One of the above may be selected.

[0033] The above is the overall configuration of electronic device 200. Next, the configuration of port controller 300 will be described.

[0034] 2 is a block diagram of a port controller 300 according to an embodiment. The port controller 300 complies with the USB (Universal Serial Bus) Type-C standard. As shown in FIG. 1, the port controller 300 can be used in the electronic device 200 that can operate as a sink device, and is equipped with a physical layer and a logical layer.

[0035] The port controller 300 includes a pin control circuit 310 , a transceiver 320 , an interface circuit 330 , a control unit 340 , a switch driver 350 , an external power supply 360 , and an internal power supply 370 .

[0036] The pin control circuit 310 is a front-end block connected to the CC1 pin and the CC2 pin, and controls the states of the CC1 and CC2 pins, as well as monitors the states of the CC pins.

[0037] The role (source / sink) of electronic device 200 is determined according to the states (pull-up, pull-down) of the CC1 pin and CC2 pin. Pin control circuit 310 includes hardware (such as pull-down resistor Rd) for determining the role of electronic device 200 and hardware (such as a voltage comparator) for determining the role of the other device. The internal configuration of pin control circuit 310 can be achieved using known technology, so a description thereof will be omitted.

[0038] The transceiver 320 complies with SOP (Start Of Packet) communication and includes a transmitter 322, a receiver 324, an encoder 326, and a decoder 328. The encoder 326 and the decoder 328 support the BMC (Biphase Mark Coding) method. The encoder 326 encodes data generated by the control unit 340, and the transmitter (line driver) 122 transmits the encoded signal. The signal received by the receiver 324 is decoded by the decoder 328 and passed to the control unit 340.

[0039] The control unit 340 performs overall control of the port controller 300. The main function of the control unit 340 is to negotiate with the source device 400 using the transceiver 320. The control unit 340 is implemented, for example, as a combination of a software program and a processor. Of the information required for negotiation, the control unit 340 acquires information specific to the electronic device 200 from the main controller 210. The information acquired from the main controller 210 is called external information. From another perspective, the port controller 300 is initialized using the external information from the main controller 210 as its initial value.

[0040] Specifically, this external information may include power data required by the electronic device 200. The format of this power data is not particularly limited as long as it allows one to be selected from a plurality of PDOs described later. For example, the required bus voltage V BUS and a list of currents.

[0041] The interface circuit 330 is capable of communicating with the main controller 210. The interface circuit 330 provides data communication between the control unit 340 and the main controller 210.

[0042] The type of interface circuit 330 is not particularly limited, but for example, 2In Figure 2, one IF pin is shown, but this IF pin can be connected to the I 2 In the C interface, the clock terminal SCL and data terminal SDA are shown in simplified form, and in the SPI, the chip select terminal CS, clock terminal SCLK, data input terminal SDI, and data output terminal SDO are shown in simplified form.

[0043] The interface circuit 330 may include a register 332. The main controller 210 communicates with the interface circuit 330 and writes data such as external information to the register 332. The control unit 340 reads the data written by the main controller 210 to the register 332 and uses it for negotiation.

[0044] 2 shows the transceiver 320 and the control unit 340 as being directly connected, but this is for convenience's sake. Data exchange between the transceiver 320 and the control unit 340 may be performed using the interface circuit 330 (register 332). That is, the transceiver 320 can write received data to the register 332, and the control unit 340 can read the data from the register 332. Conversely, the control unit 340 can write data to be transmitted to the source device 400 to the register 332, and the transceiver 320 can transmit the data written in the register 332 to the source device 400.

[0045] The data written to the register 332 by the main controller 210 may include a control signal for turning on or off the bus switch 204. When the electronic device 200 is in a safe operable state, the main controller 210 instructs the port controller 300 to turn on the bus switch 204. In response to this instruction, the control unit 340 controls the switch driver 350 to cause the switch driver 350 to turn on the bus switch 204.

[0046] Furthermore, data received by the transceiver 320 from the source device is written to the register 332. The main controller 210 can read the data received by the transceiver 320 from the source device by accessing the register 332.

[0047] The port controller 300 may also store error information and the like in the register 332. The main controller 210 accesses the register 332 and acquires the error information.

[0048] The internal power supply 370 is connected to the VDD pin and supplies the bus voltage V BUS The internal power supply 370 receives a regulated power supply voltage V REG and supplies it to at least one block inside the port controller 300.

[0049] The external power supply 360 is also connected to the VDD pin and supplies the bus voltage V BUS The external power supply 360 receives a stabilized external power supply voltage V DD2 and output it from the power output pin VOUT. DD2 The voltage level is determined according to the specifications of the main controller 210.

[0050] The above is the configuration of the port controller 300.

[0051] The operation will now be described with reference to the timing chart of FIG.

[0052] 1. Initial state In an initial state (before t0), the battery 222 is completely discharged and the electronic device 200 is inoperable. In this state, a device having a source function is connected to the receptacle 202 via a USB cable.

[0053] 2. Establishing a Source-to-Sink Relationship The counterpart device that is to become the source device establishes a connection with the sink device based on the states of the CC1 and CC2 pins (t0 to t1). Specifically, the counterpart device determines whether the electronic device 200 is a sink device based on the presence or absence of a pull-down resistor Rd provided in the electronic device 200. When the counterpart device detects the pull-down resistor Rd and determines that the electronic device 200 is a sink device, it determines that the connection has been established and sets the default 5V bus voltage V BUS Output.

[0054] Bus voltage V output by the other device BUS is supplied to the power supply pin VDD of the port controller 300, enabling the port controller 300 to operate. The port controller 300 of the electronic device 200 determines that the other device is a source device based on the states of the CC1 and CC2 pins. Specifically, the pin control circuit 310 of the port controller 300 detects the pull-up resistor Rp of the other device based on the voltages of the CC1 and CC2 pins. The pin control circuit 310 detects the bus voltage V BUS A connection with the other device is established under the conditions that a current is supplied and that the pull-up resistor Rp of the other device is detected. The pull-up resistor Rp of the other device (source device) varies depending on the current value (3A, 1.5A, 500mA). Because the CC pin generates a voltage divided by Rp and Rd, the pin control circuit 310 can detect the resistance value of the pull-up resistor Rp, i.e., the current value, according to the voltage of the CC pin.

[0055] At this stage, the main controller 210 is not operating, and the port controller 300 cannot receive a command to turn on the bus switch 204, so the bus switch 204 is off. BUS is not supplied to the main power supply 220, and the power supply voltage V DD1 is not generated.

[0056] Bus voltage V BUS The port controller 300 receives the power supply voltage V DD2and supplies it to the main controller 210 (time t1). Specifically, the external power supply 360 of the port controller 300 generates a bus voltage V BUS In response to this, the power supply voltage V DD2 This power supply voltage V DD2 This starts up the main controller 210.

[0057] In an initialization sequence that may or may not be included in the startup sequence, main controller 210 writes external information required for negotiation to register 332 of port controller 300 and initializes the data stored in register 332 of port controller 300 .

[0058] No communication via the CC pins is used in the process up to this point.

[0059] 3. Initial Negotiation (Power Negotiation) Subsequently, initial negotiation is carried out (t2 to t3). At this stage, the main controller 210 has completed its startup, and the electronic device 200 has power data necessary for the initial negotiation.

[0060] The counterpart device determines whether the electronic device 200 is compatible with USB PD. The counterpart device transmits a packet (Source_Capabilities message) including a PDO (Power Data Object) that the counterpart device supports to the electronic device 200 via communication using the CC line. The PDO specifies the combination of voltage and current that the counterpart device can supply. If the electronic device 200 supports USB PD, the electronic device 200 returns a response to the PDO from the counterpart device. If the electronic device 200 does not support USB PD, no response is returned to the PDO, and the counterpart device can therefore determine that the electronic device 200 is not compatible with USB PD.

[0061] The transceiver 320 of the electronic device 200 receives a packet including the PDO. This packet is referenced by the control unit 340. The register 332 stores external information written by the main controller 210, i.e., power data that specifies the power (voltage, current) required by the electronic device 200.

[0062] The control unit 340 selects one of the multiple PDOs based on the power data stored in the register 332. Then, it returns an identifier (number) indicating the selected PDO to the transceiver 320. The transceiver 320 transmits a packet (Request message) including the PDO identifier to the source device 400, which is the counterpart device.

[0063] When the other device receives the Request message, it determines the voltage and current to be supplied based on the data contained in the message. Then, the bus voltage V BUS The voltage level of the VCC_VOLTAGE_VOLTAGE command is set to the voltage level determined by negotiation.

[0064] 4. Control of the bus switch 204 After the initial negotiation is complete, the bus voltage V BUS Once this is stabilized, the main controller 210 instructs the port controller 300 to turn on the bus switch 204 (time t3). In response, the port controller 300 turns on the bus switch 204 (time t4). As a result, the bus voltage V BUS is supplied to the main power supply 220. The main power supply 220 is connected to the bus voltage V BUS , charging the battery 222 and supplying the power supply voltage V DD1 and supplies it to the main controller 210 and other circuit blocks. This starts up the entire electronic device 200, completing the start-up from the dead battery state.

[0065] 5. Subsequent Negotiations Even after the main controller 210 has started up, some negotiations may occur, but these negotiations are also carried out by the port controller 300 based on information obtained from the main controller 210 .

[0066] For example, if the electronic device 200 has a dual role that can switch between sink and source, it needs to support a power role swap protocol. The function of negotiation regarding the power role swap is implemented in the control unit 340 of the port controller 300. When the port controller 300 receives a power role swap request from the source device 400, it notifies the main controller 210 of the request and leaves it to the main controller 210 to decide whether or not to permit the request. The main controller 210 writes a flag indicating whether or not to permit the request into the register 332. The port controller 300 negotiates with the source device 400 based on the flag written in the register 332.

[0067] Furthermore, an option of USB PD3.0 defines a standard called PPS (Programmable Power Supply). When the electronic device 200 is PPS compatible, a function related to communication associated with PPS is also implemented in the port controller 300. The main controller 210 determines the required bus voltage V BUS The main controller 210 changes the voltage level of the required bus voltage V BUS When the voltage level of the port controller 300 changes, the port controller 300 writes the required voltage information to the register 332. The port controller 300 negotiates with the source device 400 based on the voltage information written to the register 332.

[0068] The operations of the port controller 300 and the electronic device 200 have been described above.

[0069] The advantages of the port controller 300 become clear when compared with the comparative technology. Figure 4 is a time chart showing the operation of the port controller according to the comparative technology. The port controller according to the comparative technology does not have an external power supply 360, but instead uses the bus voltage V BUS When this power supply is supplied, the bus switch is turned on regardless of control from the main power supply 220.

[0070] 1. Initial state Before time t0, the state is an initial state, in which battery 222 is completely discharged and electronic device 200 is inoperable. In this state, a device having a source function is connected to receptacle 202 via a USB cable.

[0071] 2. Establishing a Source-to-Sink Relationship The counterpart device that is to become the source device establishes a connection with the sink device based on the states of the CC1 and CC2 pins (t0 to t1). Specifically, the counterpart device determines whether the electronic device 200 is a sink device based on the presence or absence of a pull-down resistor Rd provided in the electronic device 200. When the counterpart device detects the pull-down resistor Rd and determines that the electronic device 200 is a sink device, it determines that the connection has been established and sets the default 5V bus voltage V BUS Output.

[0072] Bus voltage V BUS The port controller receives the power supply pin VDD and automatically turns on the bus switch at time t1. This causes the main power supply 220 to supply the 5V bus voltage V BUS is supplied.

[0073] At time t2, the main power supply 220 generates the power supply voltage V DD1is generated and supplied to the main controller 210. This starts up the main controller 210. In an initialization sequence that may or may not be included in the startup sequence, the main controller 210 writes external information required for negotiation to the register 332 of the port controller 300 and initializes the data stored in the register 332 of the port controller 300.

[0074] 3. Initial Negotiation (Power Negotiation) Subsequently, initial negotiation is carried out (t2 to t3). At this stage, the main controller 210 has completed its startup, and the electronic device 200 has the power data necessary for the initial negotiation. The port controller negotiates with the source device 400 based on this power data. As a result, at time t4, the source device 400 sets the bus voltage V BUS will begin supplying.

[0075] In the comparative technology, the bus switch 204 is automatically turned on regardless of instructions from the main controller, that is, regardless of the state of the internal circuitry of the electronic device 200, which can be said to pose a problem in terms of reliability.

[0076] Also, before initial negotiation, the default 5V bus voltage V BUS This reduces efficiency by operating the internal systems, including the main controller 210, at a non-optimal 5V bus voltage V BUS When the bus switch 204 is turned on in this state, the main power supply 220 operates in a low-efficiency state, and the power consumption of the electronic device 200 increases. BUS The lower the value, the larger the current flowing through the bus line, resulting in increased heat generation and power loss due to the parasitic resistance of the bus switch 204 and the bus line.

[0077] In contrast, the port controller 300 according to the embodiment uses the optimum bus voltage V BUSSince the bus switch 204 is turned on when the power supply is supplied, more efficient operation is possible compared to the comparative technology. Furthermore, the bus switch 204 is turned on based on a command from the main controller 210. The main controller 210 issues a command to turn on the bus switch 204 on the condition that the internal circuitry of the electronic device 200 is in a safe state, thereby improving reliability compared to the comparative technology.

[0078] The above-described embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in the combination of the components and the processing steps. Such modifications will be described below.

[0079] (Variation 1) In the embodiment, the control unit 340 is implemented by a processor and a software program, but it may also be configured by hardware logic.

[0080] (Variation 2) In the embodiment, the port controller 300 has been described with a focus on the source function, but the port controller 300 can also support dual roles. In this case, mainly, sink-related elements (pull-up resistor Rp), a comparator, a VCONN voltage generation circuit, etc. are added to the pin control circuit 310.

[0081] (Variation 3) In the embodiment, the switch driver 350 turns on the bus switch 204 in response to an instruction from the main controller 210, but the present invention is not limited to this. The switch driver 350 may automatically turn on the bus switch 204 when the initial negotiation is complete. In this case, the main controller 210 may monitor the state of the internal circuitry of the electronic device 200 during the startup sequence, and instruct the port controller 300 to execute the initial negotiation only if no abnormality is detected. In this way, if an abnormality is detected, the initial negotiation is not performed, and therefore the bus switch 204 is not turned on, so reliability is not impaired.

[0082] The embodiments are merely examples, and it will be understood by those skilled in the art that there are various variations in the combination of each component and each treatment process, and that such variations are also included within the scope of this disclosure or the present invention. [Explanation of symbols]

[0083] 200 Electronic equipment 202 Receptacle 204 Bus Switch 210 Main Controller 220 Main Power Supply 222 Battery 300 port controller 310-pin control circuit 320 Transceiver 330 Interface Circuit 332 registers 340 Control Unit 350 Switch Driver 360 external power supply 370 internal power supply 400 source devices 402 USB cable

Claims

1. A port controller that complies with the USB (Universal Serial Bus) Type-C standard and can be used for devices that can operate as sink devices, The device comprises: In addition to the port controller: a receptacle including a CC (Configuration Channel) pin and a VBUS pin for receiving a bus voltage supplied from a source device; a main controller that controls the port controller; a bus switch connected to the VBUS pin; a main power supply that receives the bus voltage when the bus switch is in an on state and is capable of supplying a first power supply voltage to a power supply terminal of the main controller; and The port controller an interface circuit capable of communicating with the main controller; a transceiver capable of communicating with the source device via the CC pin; a control unit capable of negotiating with the source device via the transceiver; a pin control circuit that controls and monitors the state of the CC pin; a switch driver for controlling the bus switch; a power supply circuit that receives the bus voltage and generates a second power supply voltage that is supplied to the power supply terminal of the main controller via a path separate from the first power supply voltage; A port controller comprising:

2. 2. The port controller according to claim 1, wherein said switch driver turns on said bus switch in response to an instruction from said main controller.

3. 2. The port controller according to claim 1, wherein the control unit instructs the switch driver to turn on the bus switch after completion of initial negotiation.

4. An electronic device that complies with the USB (Universal Serial Bus) Type-C standard and can operate as a sink device, a receptacle including a CC (Configuration Channel) pin and a VBUS pin for receiving a bus voltage supplied from a source device; a main controller that controls the port controller; a bus switch connected to the VBUS pin; a main power supply that receives the bus voltage when the bus switch is in an on state and is capable of supplying a first power supply voltage to a power supply terminal of the main controller; a port controller according to any one of claims 1 to 3, connected to the receptacle and the main controller; An electronic device comprising:

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