User's Manual

GE910 Hardware User Guide
GE910 Hardware User GuideGE910 Hardware User Guide
GE910 Hardware User Guide
1vv0300962 Rev.9-bis3 2013-05-20
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 64 of 87
Mod. 0805 2011-07 Rev.2
11.2.4.2. Output Lines
EAR/Line-out Output
Differential line coupling
Direct connection
(V
DC
=1.3÷1.6V)
output load resistance ≥ 8 Ω
signal bandwidth 250÷3400Hz
(@ -3dB with default filter)
max. differential output voltage 1120mV
pp
@3.14dBm0 (*)
differential output voltage 550mV
rms
@0dBm0 (*)
volume -20÷0 dB step 2dB
(*) in default condition: AT+CLVL=10, AT#HFRECG=0
TIP:
We suggest driving the load differentially; this kills all the common mode noises (click and pop,
for example), the output swing will double (+6dB) and the big output coupling capacitor will be
avoided.
However if particular OEM application needs, also a Single Ended (S.E) circuitry can be
implemented. The OEM circuitry shall be designed to reduce the common mode noise typically
generated by the return path of the big currents.
In order to get the maximum power output from the device, the resistance of the tracks has to be
negligible in comparison to the load.
NOTES:
For more information refer to Telit document: "80000NT10007a Audio Settings Application
Note".