User's Manual
HC864-AUTO Hardware User Guide
1vv0300946 Rev.4 – 2012-12-27
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Reserved. Page 21 of 77
NOTE:
To check if the HC864-AUTO has powered on, the hardware line PWRMON must be
monitored. When PWRMON goes high, the module has powered on.
NOTE:
Do not use any pull up resistor on the ON# line, it is internally pulled up. Using pull up
resistor may bring to latch up problems on the HC864-AUTO power regulator and improper
power on/off of the module. The line ON# 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 a "#" 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 module when is powered OFF or during an
ON/OFF transition.
For example:
1- Let us assume you need to drive the ON# pad with a totem pole output of a +1.8/5 V
microcontroller (uP_OUT1):