WM8980 datasheet(17/81 Pages) WOLFSON

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WM8980

PP Rev 1.6 January 2005

Mono Digital still camera; Full control over device functionality, and power control is provided,

allowing for the case of mono DSC recording, when half of the ADC and mic and line functionality

may be disabled to save power. In the mono case, the single ADC channel of audio data is sent out

over both Left and Right channels of the audio interface when normal I2S type interface format is

used. In the case where DSP mode is used, and mono data is being sent, only the signal channel of

mono data is sent. The integrated video buffer allows direct connection to the TV for display of

moving and still images.

ANALOG FM TUNER SUPPORT

An analog stereo FM tuner might be connected to the Line inputs of WM8980, and the stereo signal

listened to via headphones, or recorded, simultaneously if required.

INPUT SIGNAL PATH

The WM8980 has a number of flexible analogue inputs. There are two input channels, Left and

Right, each of which consists of an input PGA stage followed by a boost/mix stage which drives into

the hi-fi ADC. Each input path has three input pins which can be configured in a variety of ways to

accommodate single-ended, differential or dual differential microphones.

There are two auxiliary

input pins which can be fed into to the input boost/mix stage as well as driving into the output path.

A bypass path exists from the output of the boost/mix stage into the output left/right mixers.

MICROPHONE INPUTS

The WM8980 can accommodate a variety of microphone configurations including single ended and

differential inputs. The inputs to the left differential input PGA are LIN, LIP and L2. The inputs to the

right differential input PGA are RIN, RIP and R2.

In single-ended microphone input configuration the microphone signal should be input to LIN or RIN

and the internal NOR gate configured to clamp the non-inverting input of the input PGA to VMID.

Figure 6 Microphone Input PGA Circuit

WM8980 데이터시트(PDF) 17 Page - Wolfson Microelectronics plc