Garmin GMA 342 Installation Manual page 10

1.3.2 Electrical Specifications
Characteristic
Environmental
Compliance
Software
Compliance
Maximum Absolute
Audio Delay
Altitude
Maximum Days of
Continuous
Operation
Audio Panel
Functions
Intercom Functions
Headphone
Outputs
190-01878-02
Rev. 5
Table 1-3 Electrical Characteristics
RTCA DO-160F
RTCA DO-178B Level D
The Input to Output delay is less than 1.1 ms for all audio I/O excluding
entertainment audio (Music, Telephone, and Bluetooth)
55,000 Feet
Overpressure - 15,000 Feet
49
Dedicated Transceiver inputs: 3 (including TEL) for GMA 342 and 345,
4 (including TEL) for GMA 345 3-COM unit
Dedicated Receiver inputs: 5 (per notes in
inputs are uniquely selectable)
Alert (unswitched) inputs: 4 (each with configurable volume)
Input impedance: 600 Ω
Input isolation: 60 dB minimum
Alert/Receiver/Transceiver bandwidth: 100 Hz to 6.5 kHz
Special functions: Fail-safe operation
All inputs use MASQ™ processing (Master Avionics Squelch)
Max input 5 Vrms
Positions: 6 - Pilot, Copilot, 4 Passengers
Volume controls: 4 (Pilot ICS, Pilot Music, Copilot/Passenger ICS,
Copilot/Passenger Music)
Microphone input impedance: 150 Ω (compatible with 150 to 600 Ω mics)
Microphone bias voltage: 11 Vdc delivered through 470 Ω
Intercom isolation modes: 3 - Pilot, Crew, and All
Telephone interfaces: 1 full-duplex (use rear LRU pins or Bluetooth transceiver)
ICS Auto-Squelch/VOX: Independent DSP (digital signal processing) determined
thresholds for each mic.
Note that keyed intercom is optional. Auto-squelch not available when using
keyed ICS.
Output amplifiers: 3 Stereo - Pilot, Copilot, Passengers
Power, Load, and Distortion: 65 mW into 150 Ohms with <10%
THD+N @ 10% output <3% THD+N
Typical Operating Distortion: <1% THD+N
3dB Frequency Response Bandwidth: 20 Hz to 20 kHz for Music
350 Hz to 6.5 kHz for Other Audio (MICs, Radios, Alerts)
Specification
Table 1-1 regarding which AUX
GMA 342/345 Installation Manual
Page 1-4