Neo_M680 GPRS Module Hardware User Guide
Copyright © Neoway Technology Co., Ltd
23
3.7
Audio Interface
Table 3-7
Audio interface
Signal
I/O
Function
Remarks
SPKP
AO
Positive electrode of speaker output
Class AB speaker
Maximum 0.8 W@8Ω
SPKN
AO
Negative electrode of speaker output
MICP0
AI
Positive electrode of MIC0 output
Vpp≤200 mV
MICN0
AI
Negative electrode of MIC0 output
EAR-L
AO
Left sound channel of the earphone output
16/32Ω earphone driving
output
EAR-R
AO
Right sound channel of the earphone output
MIC1
AI
Single-end MIC1 input
RECN
AO
Negative electrode of receiver output
32Ω receiver driving
output
RECP
AO
Negative electrode of receiver output
M680 supports multiple lines of audio interfaces to meet customers' requirements for audio. You can switch
the audio channels and adjust the volume via AT commands. For details, see
Neo_M680 GPRS Module AT
Command Set
.
Figure 3-21 shows a reference audio interface. The peak voltage routed to MICP/MICN should not exceed
200 mV AC. AGC circuit is integrated inside the module. Electret microphone is suited.
The module can meet the requirements of common handsets with AGC and volume control.
Figure 3-21
Reference design of single-end input MIC interface
GPRS
Module
MIC
33 pF
MIC
