User's Manual

TECHNICAL MANUAL
Telit GM862-GPS
Quad Band GPS Data Terminal Module
Pag.14 of 79
Rev. 0
“Mic_MT” 1
st
differential microphone path
• line coupling AC
• line type balanced
• coupling capacitor ≥ 100nF
• differential input resistance 50kΩ
• differential input voltage ≤ 1,03V
pp
(365mV
rms
)
• microphone nominal sensitivity -45 dBV
rms
/Pa
• analog gain suggested + 20dB
• echo canceller type handset
“Mic_HF” 2
nd
differential microphone path
• line coupling AC
• line type balanced
• coupling capacitor ≥ 100nF
• differential input resistance 50kΩ
• differential input voltage ≤ 65mV
pp
(23mV
rms
)
• microphone nominal sensitivity -45 dBV
rms
/Pa
• analog gain suggested +10dB
• echo canceller type car kit hands-free
Speaker characteristics
“Ear_MT” Differential Line-out Drivers Path
• line coupling: DC
• line type: bridged
• output load resistance : ≥ 14 Ω
• internal output resistance: 4 Ω (typical)
• signal bandwidth: 150 - 4000 Hz @ -3 dB
• max. differential output voltage 1310 mV
rms
(typ, open circuit)
• differential output voltage 328mVrms /16 Ω @ -12dBFS
• SW volume level step - 2 dB
• number of SW volume steps 10
“Ear_HF” Power Buffers
path
• line coupling: DC
• line type: bridged
• output load resistance : ≥ 14 Ω
• internal output resistance: 4 Ω ( >1,7 Ω )
• signal bandwidth: 150 - 4000 Hz @ -3 dB
• max. differential output voltage 1310 mV
rms
(typ, open circuit)
• max. single ended output voltage 656 mV
rms
(typ, open circuit)
• SW volume level step - 2 dB
• number of SW volume steps 10