Headset Microphone Input (Pin 55); Headset Microphone Bias Output (Pin 53) - Enfora Enabler III-G Integration Manual

Enfora Enabler III-G
Modem Integration Guide

6.6.24. Headset Microphone Input (Pin 55)

The headset differential inputs
HSMIC and AUXI can be
amplified by the differential
handset microphone amplifier.
This amplifier has two different
gains 4.9 dB or 25.6 dB and a
bias generator HSMICBIAS
provides an external voltage of
2 V or 2.5 V to bias the
microphone.Headset Mic
Input
Maximum Input Range
Nominal Ref. Level
Microphone Pre-
Amplifier Gain
Input resistance at
HSMIC

6.6.25. Headset Microphone Bias Output (Pin 53)

Mic Bias Output
Bias Voltage on Mic(+)
Mic Bias Current
Capability
GSM0308PB001
Parameter/Conditions
Inputs 3 dBm0 (Maximum
digital sample amplitude with
PGA gain set to 0 dB),
AUXAMP gain = 18 dB, Single
HSMIC
HSMIC single input, AUXAMP
gain = 18 dB
(INMODE = 0101)
Parameter/Conditions
Set to 2.0 V
Set to 2.5 V
52
Min Typ Max
78
-10
18
40.5
Min Typ Max
1.9 2.1
2.4 2.6
2.0
Version DRAFT – 2/9/2007
Units
mV
RMS
dBm0
dB
kΩ
Units
Vdc
Vdc
mA