WM7132PE

8

Rev 4.0

CONNECTION TO A CIRRUS AUDIO CODEC

Cirrus provides a range of audio CODECs incorporating an analog microphone input interface; these

support connection to silicon microphones such as the WM7132P.

The recommended connection of a WM7132P silicon microphone 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 2.2µF decoupling

capacitor is also recommended; this should be positioned close to the VDD pin of the WM7132P.

Further information on Cirrus audio CODECs is provided in the respective product datasheet, which is

available from the Cirrus website.

Audio CODEC

OUTPUT

MICBIAS

Analogue Input pin

(eg. IN1xP)

VDD

GND

1

F

WM7132P

2.2

F

Figure 2 WM7132P Silicon Microphone Single-ended Connection

1

F

Audio CODEC

OUTPUT

MICBIAS

Non-Inverting Input pin

(eg. IN1xP)

VDD

GND

1

F

Inverting Input pin

(eg. IN1xN)

WM7132P

2.2

F

Figure 3 WM7132P Silicon Microphone Pseudo-differential Connection

MATCHED MICROPHONE PAIRS

The WM7132P Bottom Port microphone offers matched performance to the WM7121P Top Port

microphone.

Matched microphone pairs are ideal for accurate sound pick-up from opposite directions in slim, low-

profile applications. For best acoustic matching, the Top Port and Bottom Port microphones should be

positioned close together, on the same side of the PCB.

The WM7132P and WM7121P microphones offer matched sensitivity, low-frequency roll-off, and

phase response characteristics, enabling simplified system design when using these complementary

devices.