| Patent application number | Description | Published |
|---|
| 20080309313 | Systems and methods for providing device-to-device handshaking through a power supply signal - Handshaking circuits are provided in a communications cable and in a device operable to be mated with the communications cable. Before a device can utilize the power supply signal of such a communications channel, the two handshaking circuits must sufficiently identify one another over a power supply signal with a decreased voltage. The decreased voltage allows for a cable plug to be provided with a safe, protected power that cannot cause harm to a human. The decreased voltage also reduces the chance that a device can receive a primary power supply signal from the cable before the device sufficiently identifies itself. Accordingly, a laptop may be connected to a portable music player, but the voltage of the power supply signal provided by the laptop to the cable may be decreased on-cable until the handshaking circuit of the portable music player sufficiently performs a handshaking operation with a on-cable handshaking circuit. | 12-18-2008 |
| 20090108891 | BANDWIDTH CONTROL IN A MOSTLY-DIGITAL PLL/FLL - Methods and apparatus for controlling a controlled oscillator using a phase-locked loop (PLL) or frequency-locked loop (FLL) having a digital loop filter with programmable filter parameters. An exemplary PLL (or FLL) includes a digital loop filter having one or more of the programmable filter parameters, which are changed by increments during operation in order to minimize disturbances (e.g., settling transients) as the loop bandwidth of the PLL is varied from a narrow loop bandwidth to a wide loop bandwidth, or vice versa. By changing the loop filter parameters in increments the loop bandwidth can be varied with substantially no perturbation. The end result is a much faster frequency switching time, improved settling dynamics, and predictable and stable loop operating performance. According to another aspect of the invention, one or more of the programmable filter parameters are changed in order to oppose a change in tuning sensitivity of the controlled oscillator (e.g., in order to maintain a constant loop bandwidth). By holding the loop bandwidth constant, switching time is maintained substantially constant under all conditions. This allows design and production margins to be reduced in a frequency agile system, and also relaxes the tuning sensitivity linearity requirements of the controlled oscillator. | 04-30-2009 |
| 20090180353 | METHODS FOR USING AN ACCESSORY TO COMMUNICATE WITH AN ELECTRONIC DEVICE - 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. | 07-16-2009 |
| 20090180354 | METHODS FOR COMMUNICATING WITH ELECTRONIC DEVICE ACCESSORIES - 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. | 07-16-2009 |
| 20090180630 | ELECTRONIC DEVICE CIRCUITRY FOR COMMUNICATING WITH ACCESSORIES - 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. | 07-16-2009 |
| 20100260362 | ELECTRONIC DEVICE AND EXTERNAL EQUIPMENT WITH CONFIGURABLE AUDIO PATH CIRCUITRY - 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. | 10-14-2010 |
| 20110116646 | ELECTRONIC DEVICE AND EXTERNAL EQUIPMENT WITH DIGITAL NOISE CANCELLATION AND DIGITAL AUDIO PATH - Electronic devices and accessories are provided that may communicate over wired communications paths. The electronic devices may be portable electronic devices such as cellular telephones or media players and may have audio connectors such as 3.5 mm audio jacks. The accessories may be headsets or other equipment having mating 3.5 mm audio plugs and speakers for playing audio. Microphones may be included in an accessory to gather voice signals and noise cancellation signals. Analog-to-digital converter circuitry in the accessory may digitize the microphone signals. Digital voice signals and voice noise cancellation signals can be transmitted over the communications path and processed by audio digital signal processor circuitry in an electronic device. Digital-to-analog converter circuitry in the accessory may convert digital audio signals to analog speaker signals. Digital noise cancellation signals may use digital noise signals to cancel noise from digital audio signals that have been received from an electronic device. | 05-19-2011 |
