The LM3880 simple power supply sequencer offers the easiest method
to control power up sequencing and power down sequencing of multiple Independent voltage rails. By
staggering the startup sequence, it is possible to avoid latch conditions or large in-rush currents
that can affect the reliability of the system.
Available in a 6-pin SOT-23-6 package, the Simple Sequencer contains a precision enable
pin and three open-drain output flags. The open-drain output flags permit that they can be pulled
up to distinct voltage supplies separate from the sequencer VDD (so long as
they do not exceed the recommended maximum voltage of 0.3V greater than
VDD), so as to interface with ICs requiring a range of different enable
signals. When the LM3880 is enabled, the three output flags will sequentially
release, after individual time delays, thus permitting the connected power supplies to start up.
The output flags will follow a reverse sequence during power down to avoid latch conditions.
EPROM capability allows every delay and sequence to be fully adjustable. Contact Texas
Instruments if a nonstandard configuration is required.