
xE922-3GR Hardware User Guide
1VV0301272
Rev.0.8 2017-01-05
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights
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Page 83 of 112
The following figure shows a top level view of the analog Audio frontend (AFE) of xE92-3GR ABB/PMU.
The IDI connects the ABB to the Audio DSP/DBB.
Note:
All measurements done like described in AES-17 standard method for digital audio engineering. The values
included in the below tables are extracted from to the chipset datasheet.
15.1.1.
Analog IN
The audio-in path consists of an input selector, low noise amplifier LNA and following pre-filter with gain
control, second order S-D ADC and finally followed by digital decimator filter. It supports both standard
GSM (BW 4 kHz) and wideband (BW 8 kHz) speech bands as well as full BW for audio recording (16 kHz
and 24 kHz). Overall gain range of the input path goes from -6 dB to +39dB.
As indicated on below block diagram, two mono microphones inputs are available of which one can be
selected at the time, either single ended or differential mode.