SIM5218E Hardware Design
Table 9:
Audio interface signal
Audio channel
SIM5218E_HD_V1.03
11.06.2009
30
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
Figure 15: 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).
Pin name
Pin No
Function
MIC_P
43
MIC anode input
MIC_N
44
MIC cathode input
EAR_P
25
Receiver output anode
NORMAL
( default )
EAR_N
26
Receiver output cathode
HP_MICP
42
Headset MIC anode input
HPR
27
Headset right speaker
HEADSET
HPL
28
Headset left speaker
MIC_P
43
MIC anode input
MIC_N
44
MIC cathode input
SPK_P
23
Loudspeaker anode
Hand free
SPK_N
24
Loudspeaker cathode
