Speaker Interface Configuration - SimCom SIM5218E Hardware Design

SIM5218E Hardware Design
Table 9: Audio interface signal
Audio channel Pin name
MIC_P
MIC_N
NORMAL
( default )
EAR_P
EAR_N
HP_MICP
HEADSET
HPR
HPL
MIC_P
MIC_N
Hand free
SPK_P
SPK_N
It is suggested that you adopt one of two following reference circuits in order to get well speaker
effect. The differential audio signals have to be layout according to differential signal layout rules.
As following figures:

3.8.1 Speaker interface configuration

Because SPK_P and SPK_N are outputs of Class-D audio amplifier, optional EMI filtering is
shown at Figure 9; these components (two ferrite beads and two capacitors) can be added to
reduce electromagnetic interference. If used, they should be located near the SPK_P and SPK_N.
Considerable current flows between the audio output pins and the speaker, so wide PCB traces are
recommended (~ 20 mils).
SIM5218E_HD_V1.03
Pin No
43
44
25
26
42
27
28
43
44
23
24
Figure 15: Speaker interface configuration
30
Function
MIC anode input
MIC cathode input
Receiver output anode
Receiver output cathode
Headset MIC anode input
Headset right speaker
Headset left speaker
MIC anode input
MIC cathode input
Loudspeaker anode
Loudspeaker cathode
11.06.2009