User's Manual

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5.8. AUDIO CIRCUIT CONSIDERATIONS
IO200 supports both voice calls and data calls.
IO200 module supports 3 modes of operation for voice communication:
- Speakerphone
- Headset
- Raw
For both received audio (speaker) and transmit audio (microphone), the module will utilize standard iDEN audio signal
conditioning and processing.
5.9. Audio Interface
The following figure shows the expected electrical interface for audio input and output signals:
Figure 2. Electrical interface for audio input and output signals
Note that it is the integrator’s responsibility to properly interface a High Audio speaker or a Headset earpiece to the module’s
differential Audio Out terminals.
Notes:
• 15pf and 39pF capacitor should be place on audio out/ in lines to avoid chopper noise.
• Audio In/Out are differential lines, they need to be routed close to each other and need to be parallel.
5.10. Nominal Audio Signal
100Ω
0.1uF
10KΩ0.1uF
10KΩ
0.1uF
100Ω
0.1uF
100Ω
1.0uF
100Ω
1.0uF
0.1uF
18KΩ
0.1uF
18KΩ
Audio
Out
Audio
In
IO200 Module
Host Terminal
Amp
Amp
Amp
Amp