Getting Started with LTE Modem Cards
3.2 Digital Audio Interface (mPLSx3 only)
20
t
mPLS62_mPLS8_mPLAS9_mPLSx3_ug_startup_v03
2021-03-15
Public / Released
Page 19 of 21
3.2.1
Wideband Audio Codec Adapter
For using the Wideband Audio Codec Adapter together with LTE Modem Card, the Wideband
Audio Codec Adapter must be configured by switches (see
) and the
PCM or I
2
S Interface must be enabled by AT command AT^SAIC on the LTE Modem Card (see
and
).
Figure 11:
DIP Switches on Wideband Audio Codec Adapter
Legend:
1: Switch set to up position
0: Switch set to the down position
"LEDs": The colors
,
, and
indicate the color of the LEDs that light up at the Wideband Audio Codec Adapter.
The Wideband Audio Codec A5V0 and +2V9 power supply pins are connected to 3.3V
with the following limitations:
- +2V9 powers all ICs. They all are 3.3V capable. LEDs may light a little bit brighter.
- The codec's sensitivity may decrease by around 1dB.
- +5V0 feeds the handset microphone. If the Votronic handset is used with 3.3V instead of
5V feeding, its microphone sensitivity may be decreased by up to 3dB. Other handsets
or accessory may not be affected.
- +5V0 also supplies the speaker driver in the codec. With 3.3V the reference voltage is
not centered any more within 5V and positive signals may be clipped earlier than the neg-
ative signals.The corresponding codec register may be set for 3.3V operation via serial
interface to correct this behavior (Register 49, bit2 = 0).
For more details about the Wideband Audio Codec Adapter, refer to
Table 2:
DIP switch and AT command settings
Product AT^SAIC setting
Wideband Audio Codec Adapter DIP switch settings
Up
Ext.
Ext.
TC65i
(1.8V)
WB/
16kHz
LONGFS
I
2
S
Master
Down
Int.
I
2
C
Int.
MCLK
NORM
(3V)
NB/
8kHz
SHORTFS PCM
Slave
mPLSx3 AT^SAIC=4,1,1,3,0,0,1,1
0
0
1
1
0
0
0
AT^SAIC=4,1,1,3,0,0,1,0
0
0
1
0
0
0
0
AT^SAIC=5,1,1,1,0,0,1,1
0
0
1
1
0
1
0
AT^SAIC=5,1,1,1,0,0,1,0
0
0
1
0
0
1
0
up
down
