Figure 22, Audio track design, Figure 23 – Sierra Wireless WISMO218 User Manual
Page 60: Differential audio connection
WA_DEV_W218_PTS_002
Rev 005
Page 60 of 109
Product Technical Specification &
Customer Design Guidelines
Figure 22. Audio Track Design
For differential connections, it is necessary to add a 2.2KΩ resistor from MICN to GND to have a
proper bias of the microphone. Refer to the following figure.
Figure 23. Differential Audio Connection
For single-ended connections, the negative pole of the microphone, MICN, should be connected to
GND. Refer to the following figure.
Differential Audio line is
always in parallel