Neoway N715-EA - External Power Amplifier Connection

N715-EA Hardware User Guide
Chapter 5 Application Interfaces
Copyright © Neoway Technology Co., Ltd. All rights reserved.
55
Reference Design with External Power Amplifier
Figure 5-28 Reference design of the external power amplifier connection
L1
L2
INP
INN
SHDN
VDD
PVDD
VOP
VON
GND
GND
D1
D2
R1
100Ω
C3
C4C5
100nF
VBAT
C6
2.2µF
N715-EA Module
GPIO
SPK_P/EAR_P
SPK_N/EAR_N
Audio Amplifier
4.7uF
68nF
68nF
C2
C7
2.2µF
VDD
C1P
C1N
C2P
C2N
C8
4.7µF
C9
C10
C11
100pF
100pF
100pF
R2
100kΩ
R3
R4
3kΩ
220pF
3kΩ
C1
Schematic Design Guidelines
⚫
Connect the SPK/EAR output of the module to the power amplifier with differential connection
and select a power amplifier that can support differential input for the audio connection.
⚫
Note that the over-current capability of L1 and L2 must meet the current demand at the
maximum power. DCR is recommended to be less than 100 mΩ.
PCB Design Guidelines
⚫
Ensure that the width of audio input/output traces be no less than 0.5 mm.
⚫
The analog audio traces should be surrounded with ground and comply with the differential
routing rules. Isolate the traces from digital signals and clocks as well as other analog signal
traces. No signal trace crossing is allowed. Reserve enough grounding holes and ground
protection.
5.4.3 Headset Interface
N715-EA headset interface pinouts:
Table 5-2 Headset audio pin description
Signal
Pin
I/O
Function description
Remarks
AMP_VCOMP
94
-
Headset-dedicated ground
Route traces between the
left and right sound
channels of the headset,
connect to the GND of the