LEXI-R422 - System integration manual
UBX-23007449 - R02
Design-in
Page 32 of 108
C1-Public
2
Design-in
2.1
Overview
For an optimal integration of the LEXI-R422 modules in the final application board, follow the design
guidelines stated in this section.
Every application circuit must be suitably designed to ensure the correct functionality of the relative
interface, but a number of points require greater attention during the design of the application device.
The following list provides a rank of importance in the application design, starting from the highest
relevance:
1.
Module antenna connection:
ANT
and
ANT_DET
pins.
Cellular antenna circuit directly affects the RF compliance of the device integrating a LEXI-R422
module with applicable certification schemes. Follow the suggestions provided in the relative
section
for the schematic and layout design.
2.
Module supply:
VCC
and
GND
pins.
The supply circuit affects the RF compliance of the device integrating a LEXI-R422 module with
the applicable required certification schemes as well as the antenna circuit design. Very carefully
follow the suggestions provided in the relative section
for the schematic and layout design.
3.
SIM interface:
VSIM
,
SIM_CLK
,
SIM_IO
,
SIM_RST
pins.
Accurate design is required to ensure SIM card functionality reducing the risk of RF coupling.
Carefully follow the suggestions provided in relative section
for schematic and layout design.
4.
System functions:
PWR_CTRL
pin.
Accurate design is required to ensure that the voltage level is well defined during operation.
Carefully follow the suggestions provided in relative section
for schematic and layout design.
5.
Other digital interfaces: UART, USB, I2C, GPIOs, and reserved pins.
Accurate design is required to ensure correct functionality and reduce the risk of digital data
frequency harmonics coupling. Follow the suggestions provided in sections
for the schematic and layout design.
6.
Other supplies:
V_INT
generic digital interfaces supply.
Accurate design is required to ensure correct functionality. Follow the suggestions provided in
the corresponding section
for the schematic and layout design.
☞
It is recommended to follow the specific design guidelines provided by each manufacturer of any
external part selected for the application board integrating the u-blox cellular modules.
