Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: An audio host device has an electrical interface having a speaker contact, a microphone contact, and a reference contact. The reference contact is shared by a microphone and a speaker. The reference contact is also directly coupled to a power return plane of the audio host device. A difference amplifier is provided, having a cold input and a hot input. The hot input is coupled to the microphone contact. A switched attenuator circuit is also provided that has first and second states. In the first state, the attenuator circuit couples a sense point of the reference contact to the cold input, while in the second state the cold input is isolated from the reference sense point. Other embodiments are also described and claimed.

Abstract: Electronic devices and accessories such as headsets are provided. An accessory may include speakers and active noise cancellation circuitry. Microphones may be used to pick up ambient noise signals for implementing noise cancellation for the speakers. The accessory may also include a voice microphone and an ambient noise microphone that picks up ambient noise signals for implementing noise cancellation for the voice microphone. A user input interface may gather user input. Ultrasonic tone generators may transmit data between the device and accessory. The electronic device and accessory may be connected to each other by audio connectors. Hybrid circuits that each include a summer and a transconductance amplifier may be selectively switched into or out of use. When switched into use, paths between the device and accessory can support bidirectional communications such as communications involving the simultaneous flow of analog audio and microphone signals in opposite directions.

Abstract: An audio host device has an electrical interface having a speaker contact, a microphone contact, and a reference contact. The reference contact is shared by a microphone and a speaker. The reference contact is also directly coupled to a power return plane of the audio host device. A difference amplifier is provided, having a cold input and a hot input. The hot input is coupled to the microphone contact. A switched attenuator circuit is also provided that has first and second states. In the first state, the attenuator circuit couples a sense point of the reference contact to the cold input, while in the second state the cold input is isolated from the reference sense point. Other embodiments are also described and claimed.

Abstract: An audio host device has an electrical interface having a speaker contact, a microphone contact, and a reference contact. The reference contact is shared by a microphone and a speaker. The reference contact is also directly coupled to a power return plane of the audio host device. A difference amplifier is provided, having a cold input and a hot input. The hot input is coupled to the microphone contact. A switched attenuator circuit is also provided that has first and second states. In the first state, the attenuator circuit couples a sense point of the reference contact to the cold input, while in the second state the cold input is isolated from the reference sense point. Other embodiments are also described and claimed.

Abstract: An audio host device has an electrical interface having a speaker contact, a microphone contact, and a reference contact. The reference contact is shared by a microphone and a speaker. The reference contact is also directly coupled to a power return plane of the audio host device. A difference amplifier is provided, having a cold input and a hot input. The hot input is coupled to the microphone contact. A switched attenuator circuit is also provided that has first and second states. In the first state, the attenuator circuit couples a sense point of the reference contact to the cold input, while in the second state the cold input is isolated from the reference sense point. Other embodiments are also described and claimed.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: Electronic devices and accessories such as headsets are provided. An accessory may include speakers and active noise cancellation circuitry. Microphones may be used to pick up ambient noise signals for implementing noise cancellation for the speakers. The accessory may also include a voice microphone and an ambient noise microphone that picks up ambient noise signals for implementing noise cancellation for the voice microphone. A user input interface may gather user input. Ultrasonic tone generators may transmit data between the device and accessory. The electronic device and accessory may be connected to each other by audio connectors. Hybrid circuits that each include a summer and a transconductance amplifier may be selectively switched into or out of use. When switched into use, paths between the device and accessory can support bidirectional communications such as communications involving the simultaneous flow of analog audio and microphone signals in opposite directions.

Abstract: Hybrid circuits for electronic devices and accessories for electronic devices are provided. One or more pairs of hybrid circuits may convey audio signals, noise cancellation audio signals, microphone signals, control signals, and other signals between an electronic device and an accessory. The hybrid circuits may include a voltage controlled current source, a differential amplifier, separate signal and ground pins, multiple ground lines, an amplifier on a ground noise sense input line that can sense ground noise that may result from parasitic resistance, and other circuitry.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.