WM7220

Preliminary Technical Data

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PTD, Rev 2.3, December 2011

8

APPLICATIONS INFORMATION

RECOMMENDED EXTERNAL COMPONENTS

It is recommended to connect a 0.1µF decoupling capacitor between the VDD and GND pins of the

WM7220. A ceramic 0.1µF capacitor with X7R dielectric or better is suitable. The capacitor should be

placed as close to the WM7220 as possible.

CONNECTION TO A WOLFSON AUDIO CODEC

Wolfson provides a range of audio CODECs incorporating a digital microphone input interface; these

support direct connection to digital microphones such as the WM7220.

Stereo connection of two WM7220 digital microphones to the WM8994 CODEC is illustrated in Figure

2.

A 0.1µF decoupling capacitor is recommended; this should be positioned close to the VDD pin of the

WM7220. A ceramic 0.1µF capacitor with X7R dielectric or better is suitable.

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 supporting a

digital microphone interface.

WM7220

VDD

WM7220

VDD

CLK

DAT

LRSEL

CLK

DAT

LRSEL

0.1 F

0.1 F

VDD

VDD

GND

GND

GND

GND

WM8994

DMICCLK

DMICDAT1

Figure 2 Stereo WM7220 Digital Microphone Connection to WM8994