Pre-Production WM7230
w
PP, Rev 3.1, January 2014
9
APPLICATIONS INFORMATION
RECOMMENDED EXTERNAL COMPONENTS
It is recommended to connect a 0.1µF decoupling capacitor between the VDD and GND pins of the
WM7230. A ceramic 0.1µF capacitor with X7R dielectric or better is suitable. The capacitor should be
placed as close to the WM7230 as possible.
OPTIMISED SYSTEM RF DESIGN
For optimised RF design please refer to document WAN0278 (Recommended PCB Layout for
Microphone RF Immunity in Mobile Cell Phone Applications) for further information.
CONNECTION TO A WOLFSON AUDIO CODEC
Wolfson provides a range of audio CODECs incorporating a digital microphone input interface; these
support direction connection to digital microphones such as the WM7230.
Stereo connection of two WM7230 digital microphones to the WM8280 CODEC is illustrated in Figure
2.
A 0.1µF decoupling capacitor is recommended; this should be positioned close to the VDD pin of the
WM7230. A ceramic 0.1µF capacitor with X7R dielectric or better is suitable.
Further information on the WM8280 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.
Figure 2 Stereo WM7230 Digital Microphone Connection to WM8280
