WM620 Hardware User Guide
V1.1
All rights reserved by Shenzhen Neoway Technology Co., Ltd.
Page 13
2.7 Audio interface
Table 2-4, Audio interface
PIN
Signal Name
I/O
Function Description
Note
28
EAR_1P
AO
Earphone amplifier output
（
+
）
32Ω Earpiece;
typical:35mW
29
EAR_1N
AO
Earphone amplifier output
（
-
）
30
MIC_1N
AI
Microphone #1 input (-)
31
MIC_1P
AI
Microphone #1 input (+)
The WM620’s typical audio interfaces are shown in Figure 2-14. The earpiece output pins are connected
directly to the earpiece, each with its own bypass capacitor. The capacitor value is selected to optimize
performance in each design, but a value of
100pF
or less is expected (
100pF
is used in the example). The
output power for the differential ear output is typically 35mW for a full-scale +3dBm sine wave into a 32Ω
speaker.
Figure 2-14
