LE940B6 HW User Guide
Rev. 2.02
Page 48 of 111
2020-01-10
Figure 4: LE940B6 Initialization and Activation
Initialization State
Activation State
Internal State
SW_RDY
VAUX/PWRMON
ON_OFF_N
VBATT
OFF State
25 sec
250ms
130ms
80ms < Hold Time < 120ms
AT Commands Available
Initialization
NOTE:
To check whether the LE940B6 has completely powered on, monitor the
SW_RDY hardware line. When SW_RDY goes high, the module has
completely powered on and is ready to accept AT commands.
NOTE:
Do not use any pull-up resistor on the ON_OFF_N line as it is internally
pulled up. Using a pull-up resistor may cause latch-up problems on the
LE940B6 power regulator and improper powering on/off of the module. The
ON_OFF_N line must be connected only in an open-collector configuration.
NOTE:
To avoid a back-powering effect, it is recommended to avoid having any
HIGH logic level signal applied to the digital pins of the module when it is
powered OFF or during an ON/OFF transition.
Provided
to
Dekra
under
NDA
Distribution
is
Prohibited
except
for
Dekra
employees
with
a Need
to
know
