User's Manual

WM620 Hardware User Guide V1.1

2.7 Audio interface

Table 2-4, Audio interface

Signal Name

I/O

Function Description

Note

EAR_1P

Earphone amplifier output（+）

32Ω Earpiece;

typical:35mW

EAR_1N

Earphone amplifier output（-）

MIC_1N

Microphone #1 input (-)

MIC_1P

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