N58 Hardware User Guide
Chapter 5 Application Interfaces
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5 Application Interfaces
N58 provides the control, communications, peripheral, audio, display, and RF interfaces to meet the
product functional requirements in different application scenarios.
This chapter describes how to design each interface and provides reference designs and guidelines.
5.1 Power Interface
The schematic design and PCB layout of power supply are very important in the full product design,
and they strongly reflect on the product overall performance. Read the design guidelines of power
supply and comply with the correct design principles to obtain the optimal circuit performance.
Pin Name Pin No.
I/O
Function
Remarks
VBAT
27, 28, 29
PI
Power
input
of
the
module
3.4 V to 4.2 V (typical value: 3.8 V)
VDD_1P8 45
PO
1.8 V power output
V
norm
= 1.8 V
I
max
= 50 mA
GND
1, 14, 17, 20, 26, 30, 31, 44, 49, 74, 75, 77, 91,
93, 95, 97-102, 104, 106, 112, 114, 115, 121-123,
128, 129, 137, 142, 143, 146, 147, 155-192
All GND pins must be grounded.
5.1.1 VBAT
The power supply design covers two parts: schematic design and PCB layout.
Schematic Design
In GSM/GPRS mode, RF data transmission is not continuous, each burst frequency is about 217 Hz, and the
instantaneous peak current is higher than 2.5 A. Therefore, ensure that the driving capability of the power supply
is sufficient, that the power trace width is sufficient to reduce the impedance, and that there is a large capacitance
capacitor to improve the freewheeling capability. This is to ensure that the voltage does not drop below the
minimum operating voltage of the module during the instantaneous peak current.
