LM3881 Datasheet, PDF (1/27 Pages) National Semiconductor (TI) – Power Sequencer

Product
Folder
Sample &
Buy
Technical
Documents
Tools &
Software
Support &
Community
LM3881
SNVS555D – JANUARY 2008 – REVISED DECEMBER 2014
LM3881 Simple Power Sequencer With Adjustable Timing
1 Features
•1 Easiest Method to Sequence Rails
• Power-Up and Power-Down Control
• Tiny Footprint
• Low Quiescent Current of 80 µA
• Input Voltage Range of 2.7 V to 5.5 V
• Output Invert Feature
• Timing Controlled by Small Value External
Capacitor
2 Applications
• Security Cameras
• Servers
• Networking Elements
• FPGA Sequencing
• Microprocessor and Microcontroller Sequencing
• Multiple Supply Sequencing
3 Description
The LM3881 Simple Power Sequencer offers the
easiest method to control power up and power down
of multiple power supplies (switching or linear
regulators). By staggering the start-up sequence, it is
possible to avoid latch conditions or large inrush
currents that can affect the reliability of the system.
Available in VSSOP-8 package, the Simple
Sequencer contains a precision enable pin and three
open-drain output flags. When the LM3881 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. Time delays are
defined using an external capacitor and the output
flag states can be inverted by the user.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
LM3881
VSSOP (8)
3.00 mm x 3.00 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
Input
Supply
Enable
Invert
Typical System Application
DEVICE 1
LM3881
VCC
EN
FLAG1
FLAG2
INV
FLAG3
GND
EN
DEVICE 2
EN
DEVICE 3
EN
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.