User Manual

Table Of Contents
G610 GPRS Module Hardware User Manual Page 28 of 47
16 EAR-
1st Audio channel
Output is balanced and can directly operate an head set
15 EAR+
18 AUXO+
2nd Audio channel
Output is balanced and can directly operate an hand
free speaker
17 AUXO-
3.9.1 1
st
Audio Channel: Microphone
This channel is the G610 power-up default active audio channel.
The microphone input includes all the necessary circuitry to support a direct connection to an
external microphone device. It incorporates an internal bias voltage which can be adjusted by AT
command. It has an impedance of 2 k.
The bias voltage would be supplied after a voice call establish.
Parameter Conditions Min Typ Max Unit
Bias Voltage
No load
1.8 2.0 2.2 V
Gain Programmable
in 3 dB steps
0 45 dB
AC Input
Impedance
2 k
3.9.2 1
st
Audio Channel: Speaker
This channel is the G610 power-up default active output for voice calls and DTMF tones. It is
designed as a differential output with 32Ω impedance.
Parameter Conditions Min Typ Max Unit
Output Voltage
No load Single
ended
200 mVPP
AC Output
Impedance
32
DC Voltage 1.38 V
3.9.3 2
nd
Audio Channel: Microphone
This channel is switched on by AT Command.
The microphone input includes all the necessary circuitry to support a direct connection to an
external microphone device. It incorporates an internal bias voltage which can be adjusted by AT