Example-Mic Differential Connection Without An Lc Filter (Tbd); Recommended Components For A Mic Differential Connection - Sierra Wireless AirPrime SL808 Series Product Technical Specification & Customer Design Manuallines

MIC
Rev 1 Dec.10 Proprietary and Confidential - Specifications subject to change
• If no filter is used, capacitors must be removed and the coil replaced by 0
resistors as shown in
C1
Figure 4-5: Example—MIC differential connection without an LC filter (TBD)
Capacitor C1 is highly recommended to eliminate TDMA noise and it must be
connected close to the microphone.
Table 4-23 lists the recommended components to use in creating the LC filter.
Table 4-23: Recommended components for a MIC differential
connection
Component
C1
C2, C3, C4
L1, L2
Figure 4-5 on page 55.
1.2V typ
S3
MIC1_P
MIC1_N
S4
Value
12–33 pF
47 pF
100 nH
AirPrime SL module
1350 Ohm typ
Audio
ADC
100nF
100nF
1350 Ohm typ
Notes
Must be tuned depending on
the design.
Must be tuned depending on
the design.
Must be tuned depending on
the design.
55