User's Manual

LE940B6 Hardware User Guide
1VV0301331 Rev. 1.8 - 2017-03-15
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5.3.3. Unconditional Hardware Reset (RESET_N)
To unconditionally restart the LE940B6 module, the RESET_N pad must be tied low in the range
1300 - 1800 milliseconds and then released.
Figure 9 shows a simple circuit for this action.
Figure 9: Circuit for Unconditional Hardware Reset
GND
R1
R2
Q1
Unconditional
Reset Impulse
1300ms < Hold Time < 1800ms
RESET_N
NOTE:
The Unconditional Hardware Reset must always be implemented on the boards, but the software
must use it only as an emergency exit procedure, and not as a normal power-off operation.
NOTE:
Do not use any pull-up resistor on the RESET_N line or any totem pole digital output. Using a pull-
up resistor may cause latch-up problems on the LE940B6 power regulator and improper
functioning of the module. The RESET_N line must be connected only in an open-collector
configuration.