WM8980CGEFL/RV WOLFSON [Wolfson Microelectronics plc], WM8980CGEFL/RV Datasheet - Page 23

• Manufacturer Part Number: WM8980CGEFL/RV
• Description: Stereo CODEC with Speaker Driver and Video Buffer
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

Pre-Production
INPUT SIGNAL PATH
Figure 9 Microphone Input PGA Circuit
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Stereo Camcorder; The provision of two stereo microphone preamplifiers, allows support for both
internal and external microphones. All drivers for speaker, headphone and line output connections are
integrated. The selectable ‘application filters’ after the ADC provide for features such as ‘wind noise’
reduction, or mechanical noise reducing filters. The integrated video buffer allows direct connection
to a TV or VCR for both video and audio (via line outputs).
Stereo Digital still camera recording; Support for digital stereo video with audio recording is similar to
the camcorder case. But additionally if the DSC supports MP3 playback, and perhaps recording, the
ability of the ADCs to support full 48ks/s high quality stereo recording increases device flexibility. The
integrated video buffer allows direct connection to the TV for display of moving and still images.
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 the Left channel of the audio interface. 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.
AUXILIARY ANALOGUE INPUTS
An analogue stereo FM tuner or other auxiliary analogue input can be connected to the Line inputs of
WM8980, and the stereo signal listened to via headphones, or recorded, simultaneously if required.
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.
In differential mode the larger signal should be input to LIP or RIP and the smaller (e.g. noisy ground
connection) should be input to LIN or RIN.
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.
PP, Rev 3.8, May 2012
WM8980
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