Sierra Wireless WISMO218 - Manual (Page 55)

WA_DEV_W218_PTS_002 Rev 005 Page 55 of 109
Product Technical Specification &
Customer Design Guidelines
Figure 18. Example of MIC Input Single-Ended Connection without LC Filter
*Z2 is from 200Hz to 4kHz. For more characteristics refer to the Electrical Characteristics section.
The capacitor C1 is highly recommended to eliminate TDMA noise. Note that C1 must be close to the
microphone.
Recommended Components
Component Description/Details Notes
C1 12pF to 33pF needs to be tuned depending on the design
C2 needs to be tuned depending on the design
L1 needs to be tuned depending on the design