1. Field of the Invention
The invention relates to audio interface, and in particular to an audio interface device and method acquiring audio signals from either an analog or digital microphone through a common connector.
2. Description of the Related Art
An analog microphone has a 3-wire audio plug, requiring a 3-contact audio jack connector, and a digital microphone generally has a 4-wire audio plug, requiring a 4-contact audio jack connector. Conventionally, both the 3-contact audio jack connector and the 4-contact audio jack connector are simultaneously provided to an electronic system to satisfy different users who may use the analog microphone or the digital microphone. Such configuration of audio jack connectors inevitably increases dimensions and production costs of the electronic system.
Accordingly, it is desirable to propose an audio interface for an electronic system to reduce dimensions and production costs of the electronic system, the audio interface acquiring an analog or digital audio signal of an analog or digital microphone through a single common connector.
One exemplary embodiment of the invention is directed to an audio interface which comprises a connector, electrically connected with a microphone plugged therein; an analog readout circuit, acquiring an analog audio signal from an analog microphone; a digital readout circuit, acquiring a digital audio signal from a digital microphone; and a decision circuit, selectively connecting the analog or digital readout circuit to the connector to acquire the analog or digital audio signal respectively according to whether the microphone plugged into the connector is analog or digital.
The decision circuit may comprise a detection unit, detecting if a microphone plugged into the connector is analog or digital; and a switching unit, connecting either the analog readout circuit or the digital readout circuit to the connector according to the detection unit. In this exemplary embodiment, the connector is an audio jack connector with a tip contact, a ring contact, and first and second sleeve contacts, corresponding to a plug configuration of the digital microphone; wherein one of the first and second sleeve contacts is connected to a reference ground, and the other one receives the digital audio signal from the digital microphone plugged into the connector.
In addition, the detection unit controls the switching unit to connect the digital readout circuit to the connector such that the digital readout circuit sends an active voltage and a clock signal to the digital microphone through the tip and ring contacts of the connector, whereby the detection unit detects that the microphone plugged into the connector is digital when a data signal from the microphone plugged into the connector appears at the first or second sleeve contact not connected to the reference ground, otherwise determining that the microphone plugged into the connector is analog.
Another exemplary embodiment is directed to an audio interface method comprising the steps of providing a common connector electrically connected with a microphone plugged therein, providing a digital readout circuit to acquire a digital audio signal from a digital microphone, providing an analog readout circuit to acquire an analog audio signal from an analog microphone, detecting the type of microphone plugged into the common connector, and connecting either the analog or digital readout circuit to the common connector to acquire either the analog or digital audio signal according to the microphone type of the microphone plugged in the connector. Therefore, the digital or analog signal from the digital or analog microphone can be acquired merely through the common connector.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
The connector 201 electrically connects to a microphone (not shown in
The analog readout circuit 202 operates to acquire an analog audio signal if when an analog microphone is plugged into the connector 201. The digital readout circuit 203 operates to acquire a digital audio signal if a digital microphone is plugged into the connector 201.
The decision circuit 204 selectively connects the analog or digital readout circuit (202 or 203) to the connector 201 to acquire the analog or digital audio signal respectively according to whether the microphone plugged in the connector is the analog or digital microphone.
In
The detection unit 204 controls the switching unit 204b to connect VDD output and CLK output of the digital readout circuit 203 to the tip contact 201a and the ring contact 201b of the connector 201, for example controlling the two switches (SW1, SW2) in their positions 1, as depicted in
The detection unit 204a may comprise a microcontroller and a GPIO (general purpose input/output) device, both not shown in
If the analog microphone, with only one sleeve portion 11c as depicted in
Also, the decision circuit can detect the type of the microphone plugged into the connector by directly identifying the number of sleeves configured on a plug of the microphone.
The electronic system 20 further comprises an audio processing unit 220 to process the analog audio signal output by the analog readout circuit 202 or the digital audio signal output by the digital readout circuit 203. The audio processing unit 220 may comprise an audio codec to process the analog audio signal, and a conversion device to convert format of the digital audio signal for further processing.
While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
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Number | Date | Country | |
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20080285776 A1 | Nov 2008 | US |