Neoway N715-EA - Analog Audio Input (MIC)

N715-EA Hardware User Guide
Chapter 5 Application Interfaces
Copyright © Neoway Technology Co., Ltd. All rights reserved.
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5.4 Audio Interfaces
N715-EA provides many audio input/output interfaces to meet your demands for the audio function in
different environments.
5.4.1 Analog Audio Input
Signal
Pin
I/O
Function description
Remarks
MIC_N
23
AI
MIC input channel -
-
MIC_P
24
AI
MIC input channel +
-
MIC_BIAS
25
PO
Microphone bias power
supply
V
O
=2.2 V - 3 V, V
norm
=2.2 V
N715-EA supports one MIC differential input. The reference design is as follows:
Figure 5-26 Reference design of the MIC differential input
MIC_BIAS
B1
B2
510Ω
1.5kΩ
33pF
33pF
33pF
MIC_P
MIC_N
R1
R3
C1
C2
C3
C5
1μF
D1
D2
MIC
1.5kΩ
R2
2.2uF
C7
510Ω
R4
10pF
C4
10pF
C5
10pF
C6
Schematic Design Guidelines
⚫
D1 and D2 are TVS diodes to prevent MIC from introducing ESD and damaging the module.
⚫
C1 to C6 are filter capacitors to filter out undesirable frequencies. Adjust the parameters
according to the actual debugging situation.