Sierra Wireless WISMO218 SPKP, WISMO218 SPKN

WA_DEV_W218_PTS_002 Rev 005 Page 51 of 109
Product Technical Specification &
Customer Design Guidelines
SPK Outputs
The SPK interface allows for both differential and single ended speaker connections.
SPKP
WISMO218
SPKN
Figure 14. Equivalent Circuit for SPK
Table 18. Electrical Characteristics of SPK
Param eters
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*; differ ential
-
-
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]
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.
Pin Description
Table 19. Analog Audio Interface Pin Descriptions
Signa l
Pin
Numbe r
I/O
I/O Type
Descr iption
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
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