Quectel M35 - PCM Interface

GSM/GPRS Module Series
M35 User Manual
M35_User_Manual Confidential / Released 48 / 85
3.8.5. Loud Speaker Interface Design
LOUDSPKN
0R
0R
LOUDSPKP
8 ohm
Module
GND
GND
GND
Close to Speaker
10pF
33pF
33pF
10pF
10pF
33pF
GND
GND
GND
Differential
layout
0603
0603
0603
0603
0603
0603
ESD
ESD
Figure 27: Loud Speaker Interface Design
3.8.6. Audio Characteristics
Table 11: Typical Electret Microphone Characteristics
Table 12: Typical Speaker Characteristics
Parameter
Min.
Typ.
Max.
Unit
Working Voltage
1.2
1.5
2.0
V
Working Current
200
500
uA
External Microphone Load Resistance
2.2
k Ohm
Parameter
Min.
Typ.
Max.
Unit
AOUT1
Output
Single-ended
Load resistance
32
Ohm
Ref level
0
2.4
Vpp
Differential
Load resistance
32
Ohm