User's Manual

CL865-DUAL Hardware User Guide

1vv0301104 Rev.1 – 2014-03-07

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Reserved. Page 19 of 70

Mod. 0805 2011-07 Rev.2

NOTE:

The power supply must be applied either at the same time on pins VBATT and VBATT_PA,

or first applied on VBATT_PA and then on VBATT. The opposite sequence shall be avoided.

The reverse procedure applies for powering down the module: first disconnect VBATT, then

VBATT_PA, or both at once.

NOTE:

In order to prevent a back powering effect it is recommended to avoid having any HIGH logic

level signal applied to the digital pins of the CL865 when the module is powered OFF or

during an ON/OFF transition.

A flow chart showing the AT commands managing procedure is displayed below:

Modem ON Proc.

Disconnect PWR

supply

AT init sequence.

Delay 300mS

Enter AT<CR>

AT answer in

1second?

Start AT CMD.