Pin description, Application, Microphone – Sierra Wireless AIRPRIME WISMO218 User Manual
Page 49: Figure 14, Equivalent circuit for spk, Table 18, Electrical characteristics of spk, Table 19, Analog audio interface pin descriptions
WA_DEV_W218_PTS_002
Rev 006
April 29, 2010
49
Product Technical Specification &
Customer Design Guidelines
Interfaces
SPKP
WISMO218
SPKN
Figure 14.
Equivalent Circuit for SPK
Table 18: Electrical Characteristics of SPK
Parameters
Min
Typ
Max
Unit
Biasing voltage
SPKP and SPKN
-
1.4
-
V
Output swing
voltage
RL=8
: AT+VGR=6*; single ended
-
-
1
Vpp
RL=8
: AT+VGR=6*; differential
-
-
2
Vpp
RL=16
or 32: AT+VGR=6*; single ended
-
-
1.1
Vpp
RL=16
or 32: AT+VGR=6*; differential
-
-
2.2
Vpp
RL
Load resistance
6
8
-
IOUT
Output current; peak value; RL=8
-
-
90
mA
POUT
RL=8
; AT+VGR=10*;
-
-
65
mW
*
The output voltage depends on the output speaker gain set by the AT command. Please refer to document [2]
AirPrime WISMO218 AT Commands Manual.
If a single-ended connection is used, only SPKP has to be connected. The result is a maximal output
power divided by 2.
3.10.3. Pin Description
Table 19: Analog Audio Interface Pin Descriptions
Signal
Pin
Number
I/O
I/O Type
Description
MICP
3
I
Analog
Microphone positive input
MICN
4
I
Analog
Microphone negative input
SPKP
1
O
Analog
Speaker positive output
SPKN
2
O
Analog
Speaker negative output
3.10.4. Application
3.10.4.1. Microphone
The following subsections define different microphone configuration examples.
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