Turn Off - Quectel RM520N-GL Hardware Design

Table 9: Trun-on Timing of the Module
Symbol Min.
T 100ms -
VCC-FCPO#
T -
FCPO#-CLKREQ#
T 100 ms
FCPO#-PERST#
100 μs -
T
REFCLK-PERST#
T -
PERST#-RST#

3.5. Turn off

For the design that turns on the module with a host GPIO, when the power is supplied to VCC, driving
FULL_CARD_POWER_OFF# pin LOW (≤ 0.2 V) or tri-stating the pin will turn off the module. Sending the
command AT+CFUN=0 is necessary before shutting down the module.
Following is the proper shutdown handshaking process for FULL_CARD_POWER_OFF#, which complies
with the M.2 specification. Only after this process is completed, can the module successfully shutdown.
1. The host sends AT+CFUN=0 to the module.
2. The module responds OK to the host after finishing all the essential shutdown tasks.
3. If the host receives ERROR, it should try again for AT+CFUN=0 until OK is received to carry on the
power off sequence.
For details about the command, see document [3].
RM520N-GL_Hardware_Design
Typ. Max. Comment
- System turn-on time depending on the host.
The time when the module requests the PCIe clock from
100 ms -
the host.
The time when the host GPIO controls the module to exit
-
the PERST# state.
The time period during which REFCLK_P/M is stable
-
before PCIE_RST_N is inactive.
The time when the host GPIO controls the module to exit
the reset state in advance. For the host GPIO, the time is
- 390 ms the maximum time that is allowed, while for the module's
RESET# pin, it is the minimum time that is allowed. The
time will continue to be updated.
5G Module Series
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