Garmin GIA 63 Installation Manual page 109

4.6.2 Com/VOR/ILS/DIGITAL Audio Electrical Characteristics
4.6.2.1 Com Mic Key
Pin Name
COM MIC KEY*
INACTIVE: 10 ≤ Vin ≤ 33VDC or Rin ≥ 100kΩ
ACTIVE: Vin ≤ 1.9VDC with ≥ 75 uA sink current, or Rin ≤ 375Ω
Sink current is internally limited to 200 uA max for a grounded input
4.6.2.2 Com Mic Audio
Pin Name
COM MIC AUDIO IN HI
COM MIC AUDIO IN LO (GROUND)
COM MIC AUDIO has a 520 Ohm AC input impedance and supplies the microphone with a 9V bias
through 620 Ohms.
COM MIC AUDIO is set in the factory for 275 mV
microphone gain adjustment is accessible through the GDU PFD/MFD.
4.6.2.3 Com/VOR/ILS Audio
Pin Name
COM UNSQUELCHED AUDIO OUT (011-01105-4X ONLY)
COM 500Ω AUDIO OUT HI
COM 500Ω AUDIO OUT LO
VOR/LOC 500Ω AUDIO OUT HI
VOR/LOC 500Ω AUDIO OUT LO
VOICE ALERT 500Ω AUDIO OUT HI
VOICE ALERT 500Ω AUDIO OUT LO
COM UNSQUELCHED AUDIO OUT supplies at least 280 mVrms across a 500  load. This output is
referenced to ground.
500Ω COM AUDIO and 500Ω VOR/ILS AUDIO each supply 100 mW into a 500 Ω load. 500Ω VOICE
ALERT AUDIO supplies 50 mW into a 500Ω load. These are balanced outputs and the LO output must be
connected.
500Ω COM AUDIO is the summation of the COM receiver audio and COM sidetone audio.
190-00303-05
Rev. Y
Table 4-17. Com Mic Key
Table 4-18. Com Mic Audio
to modulate the transmitter at 80% nominally. The
RMS
Table 4-19. Com/VOR/ILS Audio
Connector Pin
P601 4
Connector Pin
P601 7
P601 8
Connector Pin
P601 1
P601 9
P601 10
P602 16
P602 17
P604 2
P604 3
GIA 63 Installation Manual
I/O
In
I/O
In
--
I/O
Out
Out
Out
Out
Out
Out
Out
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