u-blox SARA-G3 Series, System Integration Manual

Page: 194 / 218

SARA-G3 series - System Integration Manual
UBX-13000995 - R06 Objective Specification Appendix
Page 194 of 218
A.4.2 System functions interfaces
Module power-on
SARA-G3 and LISA series power-on sequence is initiated in one of the ways summarized in Table
41Table 41 . For more details, refer to section 1.6.1 or to the relative System Integration Manual of the
module [6], [7].
SARA-G3 series LISA-C2 series LISA-U1 series LISA-U2 series
Rising edge on the VCC pins
to a valid voltage as module
supply
Rising edge on the VCC pins
to a valid voltage as module
supply with
PWR_ON pin
permanently low when VCC is
applied
Rising edge on the VCC pins
to a valid voltage as module
supply
Rising edge on the VCC pins
to a valid voltage as module
supply
Low level on the PWR_ON pin
for appropriate time period
Low pulse on the PWR_ON
pin for appropriate time period
Low pulse on the PWR_ON
pin for appropriate time period
Low pulse on the PWR_ON
pin for appropriate time period
Pre-programmed RTC alarm
(external 32 kHz at EXT32K
needed for SARA-
G300/G310) Pre-programmed RTC alarm Pre-programmed RTC alarm
RESET_N input pin released
from the low level
RESET_N input pin released
from the low level
Table 41: Summary of power on events among modules
The same compatible external power-on circuit can be implemented for SARA-G3 series and LISA series
even if there are minor differences in the
PWR_ON input voltage levels ranges and in the low level time
or low pulse time to switch-on the module, as reported in Table 42Table 42 or in the relative datasheet
of the module [1], [3], [4], [5]. PWR_ON falling edge (i.e. low pulse) is required for LISA series,
but it is not required for SARA-G3 series. External pull-up is not needed for LISA-C2 series since
internal pull-up is provided.
Module power-off
SARA-G3 and LISA modules can all be properly switched off by means of the AT+CPWROFF command.
Additionally, all LISA-U2 modules, except LISA-U200-00S, can be properly switched off by low pulse on
the
PWR_ON pin, as reported in Table 42Table 42 or in the relative datasheet of the module [5].
Module reset
SARA-G3 series and LISA series modules reset can be performed in one of the following ways:

Forcing a low level on the RESET_N pin, causing an “external” or “hardware” reset

By means of the AT+CFUN command, causing an “internal” or “software” reset
The same compatible external reset circuit can be implemented for SARA-G3 series and LISA series even
if there are minor differences in the
RESET_N input voltage levels ranges and in the low level time, as
reported in Table 42Table 42 or in the relative datasheet of the module [1], [3], [4], [5].
Additional precautions are suggested for the RESET_N line of LISA-U series modules, depending on the
application board handling, to satisfy ESD immunity test requirements as described in the
LISA-U Series
System Integration Manual [7].