WM7120 Wolfson Microelectronics plc, WM7120 Datasheet - Page 7

• Manufacturer Part Number: WM7120
• Description: Analogue Silicon Microphone
• Manufacturer: Wolfson Microelectronics plc

Pre-Production
APPLICATIONS INFORMATION
RECOMMENDED EXTERNAL COMPONENTS
Figure 1 WM7120 Recommended External Components
Note:
1.
CONNECTION TO A WOLFSON AUDIO CODEC
Figure 2 Connection of WM7120 to WM8990
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The value of C2 should be selected with reference to the input impedance of the analogue input the microphone is
connected to. C2 and the input impedance create a high pass filter, the value of C2 should be selected to pass the
lowest frequency of audible interest.
Wolfson has a range of audio CODEC’s, DAC’s and ADC’s with microphone input interfaces which
support the direct connection of the WM7120. As an example, Figure 2 details the connection of the
WM7120 to the WM8990 audio CODEC. The same principles can be applied to Wolfson devices
which support microphone inputs. Further details on the WM8990 can be obtained form the Wolfson
website.
PP, Rev 3.0, May 2009
WM7120
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