LN920 HW Design Guide
1VV0301730 Rev. 1
Page 37 of 81
2021-08-11
Not Subject to NDA
Power On
To turn on the LN920, the FULL_CARD_POWER_OFF# pin must be asserted to high.
Note/Tip: To turn on the LN920 module, the RESET# pin must not be
asserted to low.
6.2.1.
Initialization and Activation State
After turning on the LN920, the module is not instantly activated because the SW initialization
process takes some time to complete.
For this reason, it is recommended not to
communicate with the LN920 during this initialization phase.
When the AT command interface is accessible via USB port, the device might not be yet fully
operational.
In general, as shown in below figure, the LN920 becomes fully operational (in
the Activation State) at least
50
seconds after the FULL_CARD_POWER_OFF# line is
asserted.
As shown in the diagram above, Boot OK
*
pin will indicate when the module is activated.
When the line status transitions to high, the module has completed boot up.
Output high level
2.28V
2.85V
Output low level
0V
0.4V
Low-level input leakage current
1000 uA
High-level input leakage current
-20 uA
20 uA
