THREE-RAIL SIMPLE POWER SEQUENCER

DESCRIPTION

The UTC UPSS3880 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-26 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 UTC UPSS3880 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.

FEATURES

* Qualified for Automotive Applications
* Simple Solution for Sequencing 3 Voltage Rails from a Single Input Signal
* Power-Up and Power-Down Control
* Low Quiescent Current of 25µA
* Input Voltage Range of 3.3V to 5.5V
* Standard Timing Options Available