Neoway N21 Series User Manual

N21
Hardware User Guide
Copyright © Neoway Technology Co., Ltd. All rights reserved.
8
Figure 3-1 Recommended circuit design 1
Power Supply N21 Module
D1
C1 C2 C3 C4
Close to the pin of the module
VBAT
Test point
I_max
C5

The maximum input voltage is 4.3 V and the typical value is 3.6V.

The protection voltage across D1 should not exceed the maximum input voltage the module can
bear.
Place TVS diode close to the input interface of the power supply to clamp the surge voltage
before it enters back-end circuits. Therefore, the back-end components and the module are
protected.

A large bypass tantalum capacitor (220 μF or 100 μF) or aluminum capacitor (470 μF or 1000 μF)
is expected at C1 to reduce voltage drops during bursts. Its maximum safe operating voltage
should be higher than 1.5 times the voltage across the power supply.

Place a bypass capacitor of low-ESR close to the module to filter out high-frequency noise from
the power supply.
A controllable power supply is preferable if the module is used in harsh conditions. Figure 3-2 shows
the recommended schematic design.

Neoway N21 Series Specifications

General

Brand	Neoway
Model	N21 Series
Category	Control Unit
Language	English