SimCom T5320, Руководство пользователя

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T5320_User Guide_V1.02
17
2012-08-10
7 Gray GPIO2 I/O by AT
commands
8 Red ADC I
9 Purple SPK- O
10 Blue MIC- I
6.3.1 Audio interface
T5320 has one pair of audio input and audio output; it can be connected to a speakerphone directly.
Figure 15: Speaker reference circuit
Customer can set the terminal MIC gain level to make the sounds louder so that the listener can hear more clearly.
And if the sound a little lower on the terminal side, customer can use the “AT +CLVL” to make the sound higher
so that customer can hear clearly.
The AT commands should be send to the terminal by RS232 or USB interface, and the following table shows the
detail commands.
Table 5: MIC input characteristics
Parameter Min Typ Max Unit
Working Voltage - 1.8 - V
Working Current 0.07 0.4 1 mA
External Microphone Load Resistance 1.2 2.2 k Ohms
Table 6: Speaker output characteristics
Parameter Min Typ Max Unit
Quiescent Current - 2.5 4 mA
Load resistance - 8 - Ohm
Output power(1KHz) - 500 - mW
Table 7: Audio parameter
Parameter Influence to Range Gain range Calculation AT command
micAmp1
MICP/MICN
analogue amplifier
0…1 0…24dB 2 steps AT+CMICAMP1