Huawei Technologies Co. Ltd UM01-HW Manuel D’Utilisation
MC703 CDMA EV-DO Wireless Module V100R001
Product Description
Issue 1.00 (2009-9-10)
Huawei Proprietary and Confidential
Page 30 of 40
these four signals for ESD protection. The TVS diodes should be placed as close to the USIM
card seat as possible.
card seat as possible.
4.4 Audio Interfaces
The UM01-HW UMTS module provides two audio input/output (I/O) interfaces. Table 4-3
shows the signals of the audio interfaces.
shows the signals of the audio interfaces.
Table 4-3 Signals of the audio interfaces
Pin Number Signal Name
Description
51
MIC1_N
Negative pole of the input of the first audio interface
53
MIC1_P
Positive pole of the input of the first audio interface
47
EAR1_N
Negative pole of the output of the first audio interface
49
EAR1_P
Positive pole of the output of the first audio interface
58
MIC2_N
Negative pole of the input of the second audio interface
60
MIC2_P
Positive pole of the output of the second audio interface
54
SPKR_OUT_N
Negative pole of the output of the second audio
interface
interface
56
SPKR_OUT_P
Positive pole of the output of the second audio interface
The input and output signals on the first audio interface are fully differential and thus have
good performance of resisting RF interference. This audio interface can be used in handset
connection mode without any external audio frequency amplifier (AFA).
good performance of resisting RF interference. This audio interface can be used in handset
connection mode without any external audio frequency amplifier (AFA).
If audio signals are in differential pairs, the lines on the printed circuit board (PCB) should be
equidistantly laid in parallel with each other. The lines should be short, the filter circuits of the
two sides should be symmetric, the differential pair signals should be close to each other, and
the grounding is required. The differential pair signals of the audio output and the differential
pair signals of the audio output should be effectively separated through grounding. In addition,
the signals should be away from the circuits of the power supply, RF, and antenna.
equidistantly laid in parallel with each other. The lines should be short, the filter circuits of the
two sides should be symmetric, the differential pair signals should be close to each other, and
the grounding is required. The differential pair signals of the audio output and the differential
pair signals of the audio output should be effectively separated through grounding. In addition,
the signals should be away from the circuits of the power supply, RF, and antenna.
Differentiate and isolate functional modules during PCB design of the UM01-HW UMTS
module.
module.