Audio switch with turn-off helper for digital interface
AssigneeQUALCOMM Incorporated
InventorsDongyang TANG, Ramkumar SIVAKUMAR, Khaled Mahmoud ABDELFATTAH ALY
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Abstract
An integrated circuit is provided with a terminal that functions to pass a data signal during a high-speed data mode of operation and to pass an audio signal during an audio mode of operation. The integrated circuit includes an audio source that couples to the terminal through an audio pass transistor during the audio mode of operation. To maintain the audio pass transistor off during the high-speed data mode of operation, the integrated circuit includes a first transistor coupled between the terminal and a gate of the audio pass transistor. The first transistor conducts negative charge from the terminal to the gate of the audio pass transistor.
Claims20
An integrated circuit, comprising:
- an integrated circuit terminal;
- an audio pass transistor having a first drain/source terminal coupled to the integrated circuit terminal;
- and
- a first transistor having a first drain/source terminal coupled to a gate of the audio pass transistor and having a second drain/source terminal coupled to the integrated circuit terminal.
A method of controlling an audio pass transistor, comprising:
- during a high-speed data mode of operation:
- coupling a gate of the audio pass transistor through a resistor to ground;
- driving a high-speed data signal through an integrated circuit terminal coupled to the audio pass transistor to charge the integrated circuit terminal with a negative voltage;
- and
- coupling the negative voltage through a first transistor coupled between the integrated circuit terminal and the gate of the audio pass transistor to maintain the audio pass transistor off during the high-speed data mode of operation.
An integrated circuit, comprising:
- an integrated circuit terminal;
- an audio source for an audio signal;
- an audio pass transistor coupled between the audio source and the integrated circuit terminal;
- a resistor coupled to ground;
- a first switch configured to couple a gate of the audio pass transistor to ground through the resistor during a high-speed data mode of operation for the integrated circuit;
- and
- means for coupling a negative charge on the integrated circuit terminal to a gate of the audio pass transistor during the high-speed data mode of operation.
Dependencies are inferred from the claim text.