User's Manual

LE940B6 Hardware User Guide

1VV0301331 Rev. 1.8 - 2017-03-15

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Figure 4: LE940B6 Initialization and Activation

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.