WM7121

Preliminary Technical Data

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PTD, Rev 2.0, October 2012

8

CONNECTION TO A WOLFSON AUDIO CODEC

Wolfson provides a range of audio CODECs incorporating an analogue microphone input interface;

these support connection to silicon microphones such as the WM7121.

The recommended connection of a WM7121 silicon microphone to the WM8994 is illustrated in

Figure 2 (for single-ended mode) and Figure 3 (for pseudo-differential mode).

A DC blocking capacitor is required, as described in the previous section. A 1µF decoupling capacitor

is also recommended; this should be positioned close to the VDD pin of the WM7121.

Further information on the WM8994 is provided in the product datasheet, which is available from the

Wolfson website. The equivalent connections can be made to other Wolfson devices in a similar

manner.

Figure 2 WM7121 Silicon Microphone Single-ended Connection to WM8994

Figure 3 WM7121 Silicon Microphone Pseudo-differential Connection to WM8994