Fairchild Semiconductor Corporation

Peter Chadbourne

Gregory A Maher

James A Siulinski

Myron J Miske

John R Turner

Christian Klein

Greg Maher

This document discusses, among other things, circuits and methods for providing an indication of an impedance between a detecting pin and a first signal pin of an audio socket using first and second comparators to, among other things, determine if moisture is present in the audio socket. If moisture is present in the audio socket, communication between an audio processing unit and the audio socket can be disabled.

Audio jack insertion/removal fault detection

A detection circuit can be configured to receive a digital value from an identification register and to determine a resistance at a conducting terminal of an audio or video jack plug using the digital value. The detection circuit can include a current source that outputs a current according to the digital value from the identification register and a comparator that compares a reference voltage to a voltage created by the current source across the resistance at the conducting terminal of the audio or video jack plug. A control logic circuit can be configured to store the digital value in the identification register, generate an interrupt signal to cause a processor to read the digital value, and identify a function of an accessory device including the audio or video jack plug, when the detection circuit determines the resistance at the conducting terminal of the audio or video jack plug.

Detecting accessories on an audio or video jack

This document discusses, among other things, a charging emulator configured to be coupled to an electrical interface, the charging emulator including a control circuit configured to receive information about a peripheral device coupled to the electrical interface and a charger circuit configured to provide power to the electrical interface using the received peripheral device information. In an example, the charging emulator can include a component of a host device including a low-power state, and the charger circuit can be configured to provide power to the electrical interface when the host device is in the low-power state.

Peripheral device host charging

An apparatus comprises an audio or video jack connector configured to receive an audio or video jack plug of a separate device, a detection circuit in electrical communication with the connector, and a processor communicatively coupled to the detection circuit. The connector includes an electrical contact for connection to a conducting terminal of the plug. The detection circuit is configured to determine a resistance at the conducting terminal. The resistance is a resistive load of the separate device at the conducting terminal of the plug. The processor is configured to identify a function of the separate device according to the determined resistance, and configure an operation of the apparatus according to the determined function.

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Portland, ME, United States of America

Peter Chadbourne