Filter
Top Products
LZT 123 1836 49
5.9.1 Auxiliary Audio To Mobile Station (AUXIP, AUXIN)
AUXI is a differential auxiliary analogue audio input to the wireless modem.
Internally, the signal is routed to the CODEC (COder/DECoder), where it is converted
to digital audio and mapped to an internal bus.
All sources must be AC-coupled to avoid attenuation of low frequencies. Use a
capacitor greater than the value shown in the table below.
The AUXI input is a passive network followed by the transmit part of the CODEC.
Parameter Conditions Min Typ Max Unit
max input gain 142 158 178 mVrms
Input voltage full scale
min input gain 447 501 564 mVrms
Frequency response -3dB cut-off 300 3400 Hz
Output dc bias level 2.16 2.4 2.64 V
AC coupling capacitance 1
µF
5.9.2 Auxiliary Audio From Mobile Station (AUXOP, AUXON)
The auxiliary output is a differential analogue audio output from the wireless modem
and may be used to drive a speaker or an earpiece. The interface has an internal
100nF coupling capacitor; a load of 10kohm will provide a near full-scale output
capability between 300 to 4300 Hz.
The table below shows the audio signal levels for AUXO.
Parameter Conditions Min Typ Max Unit
Output voltage full scale RL =10k 670 750 840 mVrms
Frequency response -3dB cut-off (RL =10k) 225 Hz