Users Manual

GSM/GPRS Module Series
M66 Hardware Design
M66_Hardware_Design Confidential / Released 48 / 82
3.8.4. Earphone Interface Design
Figure 27: Earphone Interface Design
3.8.5. Audio Characteristics
Table 10: Typical Electret Microphone Characteristics
Table 11: 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