Wolfson Microelectronics Limited

Cirrus Logic Inc.

David Sinai

Peter John Frith

A wireless cellular telephone with an audio codec for converting digital audio signals to analog audio signals. The audio codec comprises two digital audio bus interfaces for coupling to respective digital audio buses, and a digital-only signal path between the two digital audio bus interfaces, such that no analog processing of the audio signals occurs in the digital-only signal path.

Wireless cellular telephone with audio codec

The present invention provides an audio codec for converting digital audio signals to analogue audio signals, the audio codec comprising: two digital audio bus interfaces for coupling to respective digital audio buses; a digital-only signal path between the two digital audio bus interfaces, such that no analogue processing of the audio signals occurs in the digital-only signal path.

Cellular wireless telephone and audio codec therefor

The present invention provides a method of operating a digital audio device, the method comprising: receiving a voice call; receiving another digital audio signal which is not a voice call; mixing the two received signals; transmitting the mixed signal wirelessly to another device.

Audio device and method

Portable wireless telephony device

The present invention relates to battery power peripheral devices such as MP3 players which are also periodically connected to another power source such as a mains wall socket or USB cable power bus. In particular, but not exclusively, the present invention relates to regulation of these voltage sources. In general terms the present invention provides a multiple supply rail for the load regulators of a power supply circuit for a battery powered device. One supply rail is coupled to the battery, and another is coupled to a non-battery source such as an external mains regulated source and/or a bus power wire from a USB cable or similar. The regulators have multiple inputs, each for taking their input voltage from one of these supply rails.

Power supply circuit for portable battery powered device

The present invention provides a digital bus circuit comprising: a bus conductor having two sections each connected to a pass circuit, each bus section being connected to two bus interfaces for respective circuits; at least three of the bus interfaces comprising a tri-state output buffer having a tri-state mode and one or more logic output modes; wherein in a unitary bus mode the tri-state output buffers are arranged such that only one of said output buffers is not in a tri-state mode, and the pass circuit is arranged to substantially couple said bus sections; and wherein in a dual bus mode the tri-state output buffers are arranged such that only one of the output buffers connected to each bus section is not in a tri-state mode, and wherein the pass circuit is arranged to substantially isolate said bus sections.

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Edinburgh, United Kingdom

David Sinai