User's Manual

UE910 V2 Hardware User Guide

1VV0301065 Rev.1 – 2013-12-12

During the Initialization state, any kind of AT-command is not available. DTE must wait for the

Activation state to communicate with UE910 V2.

To check if the UE910 V2 has powered on, the hardware line VAUX/PWRMON must be monitored.

When VAUX/PWRMON goes high, the module has powered on.

NOTE:

Do not use any pull up resistor on the ON_OFF* line. It is pulled up with 250kΩ internally. Using a

pull up resistor may bring latch up problems on the UE910 V2 power regulator and improper power

on/off of the module. The line ON_OFF* must be connected only in open collector configuration.

NOTE:

In this document all the lines are inverted. Active low signals are labeled with a name that ends with

"*" or with a bar over the name.

NOTE:

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

signal applied to the digital pins of the UE910 V2 module when the module is powered OFF or during

an ON/OFF transition.

For example:

1. To drive the ON_OFF* pad with a totem pole output of a +3/5 V microcontroller (uP_OUT1):

2. To drive the ON_OFF* pad directly with an ON/OFF button: