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
µ
F
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
Ω
670
750
840
mVrms
Frequency response
-3dB cut-off (RL =10k
Ω
) 225
Hz
Содержание GS64
Страница 1: ...GS64 GSM GPRS Modem Integrators Manual...
Страница 8: ...LZT 123 1836 8 Overview...
Страница 22: ...LZT 123 1836 22 Integrating the Wireless Modem...
Страница 64: ...LZT 123 1836 64 Figure 5 15 1 Typical circuit for LEDs...
Страница 91: ...LZT 123 1836 91 Developers Kit...