Abstract: A method for using driver circuitry to drive a load having an unknown impedance magnitude includes (a) in a configuration mode of the driver circuitry, determining a required power supply voltage for a driver stage to drive the load, and (b) in a driving mode of the driver circuitry, (1) driving the load via the driver stage in response to an input signal, and (2) controlling a power supply to provide the required power supply voltage to the driver stage as a static voltage, while driving the load via the driver stage in response to the input signal.

Abstract: A method for using driver circuitry to drive a load having an unknown impedance magnitude includes (a) in a configuration mode of the driver circuitry, determining a required power supply voltage for a driver stage to drive the load, and (b) in a driving mode of the driver circuitry, (1) driving the load via the driver stage in response to an input signal, and (2) controlling a power supply to provide the required power supply voltage to the driver stage as a static voltage, while driving the load via the driver stage in response to the input signal.

Abstract: A method for accessory management and data communication between a portable electronic device and an accessory via audio port is disclosed. The method involves using a microphone line of the accessory in different communication modes including a MIC data mode and a power mode. In the MIC data mode, the MIC line disconnects from a microphone load to operate on a voltage above a predetermined threshold whenever the accessory needs to communicate with the host electronic device. In the MIC power mode, the MIC line connects with the microphone load for the normal operation of the microphone.

Abstract: A universal serial bus (USB) hub includes a USB AFE circuit module, a hub core and an isolator circuit module interposed between the USB AFE circuit module and the hub core. Data communications between the hub core and the first USB AFE circuit module pass through the isolator circuit module. A method for communicating through a universal serial bus hub includes providing a USB AFE circuit module, providing a hub core, providing an isolator circuit module interposed between the USB AFE circuit module and the hub core, and directing communication from the USB AFE circuit module to the hub core through the isolator circuit module.

Abstract: In an example embodiment a headset includes a phone jack, a speaker connected to the phone jack, a microphone coupled to the phone jack and a resistive switch string coupled to the phone jack to the same ring of the phone jack as the microphone. In another example an integrated circuit device includes a charge pump, a multi-voltage LDO having an input which is capable of being coupled to an output of the charge pump, an ADC; and a pull-up resistor coupled between an output of the LDO and an input of the ADC. In another example embodiment, a method for headset signal multiplexing includes providing a headset with a plurality of signal sources and voltage division multiplexing the plurality of signal sources on a common wire.

Abstract: A universal serial bus (USB) hub includes a USB AFE circuit module, a hub core and an isolator circuit module interposed between the USB AFE circuit module and the hub core. Data communications between the hub core and the first USB AFE circuit module pass through the isolator circuit module. A method for communicating through a universal serial bus hub includes providing a USB AFE circuit module, providing a hub core, providing an isolator circuit module interposed between the USB AFE circuit module and the hub core, and directing communication from the USB AFE circuit module to the hub core through the isolator circuit module.

Abstract: A method for accessory management and data communication between a portable electronic device and an accessory via audio port is disclosed. The method involves using a microphone line of the accessory in different communication modes including a MIC data mode and a power mode. In the MIC data mode, the MIC line disconnects from a microphone load to operate on a voltage above a predetermined threshold whenever the accessory needs to communicate with the host electronic device. In the MIC power mode, the MIC line connects with the microphone load for the normal operation of the microphone.

Abstract: A universal serial bus (USB) hub includes a USB AFE circuit module, a hub core and an isolator circuit module interposed between the USB AFE circuit module and the hub core. Data communications between the hub core and the first USB AFE circuit module pass through the isolator circuit module. A method for communicating through a universal serial bus hub includes providing a USB AFE circuit module, providing a hub core, providing an isolator circuit module interposed between the USB AFE circuit module and the hub core, and directing communication from the USB AFE circuit module to the hub core through the isolator circuit module.

Abstract: A communication interface hub includes multiple ports, where one of the ports is an upstream port operative to be in direct and/or indirect communication with a host and at least one other of the ports is a downstream port operative to be in direct and/or indirect communication with at least one device. At least one hub core is coupled to the ports and implements at least one physical hub, and at least one virtual hub core is coupled to the ports and implements at least one virtual hub. The virtual hub is detectable as at least one physical hub by the host to cause the host to allocate an additional time delay in waiting for responses to signals output by the host.

Abstract: In an embodiment, an analog front end (AFE) bridge for a SLPI PHY includes: an AFE LINK-side circuit having at least one pair of differential LINK-side nodes which does not conform to SLPI PHY specifications; an AFE PHY-side circuit having a pair of differential PHY-side nodes conforming to SLPI PHY specifications, wherein the AFE PHY-side circuit is coupled to the AFE LINK-side circuit; and a termination control circuit coupled to the AFE PHY-side circuit. A method of bridging a legacy LINK circuit to a SLPI PHY circuit includes: communicating with a legacy LINK circuit with a legacy LINK protocol; communicating with a SLPI PHY circuit with a SLPY PHY protocol over a differential pair; converting outputs of the legacy LINK circuit into inputs of the SLPI PHY circuit; converting outputs of the SLPI PHY circuit into inputs of the legacy LINK circuit; controlling a termination of the differential pair.

Abstract: A cable detection circuit for a device, set forth by way of example and not limitation, includes a generator circuit operative to provide currents on a line of a communication interface. A controller is coupled to the generator circuit and operative to detect an amount of capacitance on the line based on the provided currents. The controller is operative provide an output based on the detected amount of capacitance, the output indicating whether a cable is connected to the device via the communication interface.

Abstract: A universal serial bus (USB) hub includes a USB AFE circuit module, a hub core and an isolator circuit module interposed between the USB AFE circuit module and the hub core. Data communications between the hub core and the first USB AFE circuit module pass through the isolator circuit module. A method for communicating through a universal serial bus hub includes providing a USB AFE circuit module, providing a hub core, providing an isolator circuit module interposed between the USB AFE circuit module and the hub core, and directing communication from the USB AFE circuit module to the hub core through the isolator circuit module.

Abstract: In an example embodiment a headset includes a phone jack, a speaker connected to the phone jack, a microphone coupled to the phone jack and a resistive switch string coupled to the phone jack to the same ring of the phone jack as the microphone. In another example an integrated circuit device includes a charge pump, a multi-voltage LDO having an input which is capable of being coupled to an output of the charge pump, an ADC; and a pull-up resistor coupled between an output of the LDO and an input of the ADC. In another example embodiment, a method for headset signal multiplexing includes providing a headset with a plurality of signal sources and voltage division multiplexing the plurality of signal sources on a common wire.

Abstract: In an embodiment, an analog front end (AFE) bridge for a SLPI PHY includes: an AFE LINK-side circuit having at least one pair of differential LINK-side nodes which does not conform to SLPI PHY specifications; an AFE PHY-side circuit having a pair of differential PHY-side nodes conforming to SLPI PHY specifications, wherein the AFE PHY-side circuit is coupled to the AFE LINK-side circuit; and a termination control circuit coupled to the AFE PHY-side circuit. A method of bridging a legacy LINK circuit to a SLPI PHY circuit includes: communicating with a legacy LINK circuit with a legacy LINK protocol; communicating with a SLPI PHY circuit with a SLPY PHY protocol over a differential pair; converting outputs of the legacy LINK circuit into inputs of the SLPI PHY circuit; converting outputs of the SLPI PHY circuit into inputs of the legacy LINK circuit; controlling a termination of the differential pair.

Abstract: The coupling of an electret microphone is detected and identifying whether there is monaural or stereo speakers coupled to the USB connector is accomplished by coupling a current source to the USB ID terminal and detecting the voltage on the ID terminal. If the voltage on the ID line is substantially below the voltage associated with any other accessory when an electret microphone is coupled between the ID terminal and the ground terminal, and a microphone bias resistor is coupled to the ID line. On detection of an electret microphone being coupled between the ID terminal and the ground terminal, whether there is a monaural or stereo speakers coupled to the USB connector is determined by detecting the impedance on the one of the D+ and D? terminals to which a monaural speaker would not be coupled. An open circuit indicates a monaural speaker, otherwise stereo speakers are connected. An alternate embodiment is disclosed.

Abstract: Methods and apparatus for adding an autonomous controller to an existing architecture such as by way of example, portable devices such as cell phones, MP3 players, and digital cameras. A circuit interposed between the memory card and the system controller of the device is controllable to couple the memory card to the system controller, or to couple the memory card to a high speed I/O controller on the circuit. When the memory card is coupled to the high speed I/O controller on the circuit, the circuit provides signals to the system controller indicative of a memory card removal event. In systems having an I/O connection such as a USB connection, the circuit also disconnects that connection from the system controller, provides signals to the system control indicative of a USB disconnect and connects the I/O connection to the memory card through a high speed data transfer unit to provide a higher speed I/O capability. Various features and capabilities are disclosed.

Abstract: A switching circuit for a television set is coupled to the television microprocessor and associated power supply on one end, and to the standby power supply portion of a T-chip on the other end. The T-chip is not powered during the "off" times of the television thus reducing the power consumption of the circuit. The switching circuit operates to enable the standby power supply of the T-chip upon receipt by the microprocessor of an "on" command after which the T-chip will enable the horizontal drive circuits upon the receipt of a further "on" command.

Abstract: A method and apparatus for apportioning standby power implements a first transition mode between standby and run modes of operation in which a control circuit is energized by a standby power supply in a fully active state and generates an on/off command signal responsive to detection of an input signal and a second transition mode between the standby and run modes of operation in which the control circuit is energized by the standby power supply in a partially active state and generates the on/off command signal and a drive signal generator is fully energized by the standby supply. An intermediate transition mode may also be implemented between the first and second transition modes, in which the control circuit and the generator are both energized in a fully active state for a brief interval by the standby power supply and an auxiliary energy source.

Abstract: An automatic degaussing circuit provides a video display apparatus with a degaussing capability over a wide range of ac mains sources. An ac mains source is coupled to a degaussing coil by a series interconnection of first and second temperature-sensitive resistances. The temperature-sensitive resistances have oppositely-tending temperature coefficients, so that a total dc impedance of the automatic degaussing circuit initially decreases after power is applied to the circuit.