Datasheet

Input Supply
(2.7 V ± 5.5V)
VCC
LM3881
FLAG1
GND
C
ADJ
EN
FLAG3
FLAG2
INV
TADJ
Flag 1
Flag 2
Flag 3
VCC
LM3881
FLAG2
GND
EN
TADJ
FLAG1
FLAG3
INV
1
2
4
3
6
7
8
5
LM3881
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SNVS555C JANUARY 2008REVISED APRIL 2013
LM3881 Power Sequencer
Check for Samples: LM3881
1
FEATURES
DESCRIPTION
The LM3881 Power Sequencer offers the easiest
2
Easiest Method to Sequence Rails
method to control power up and power down of
Power Up and Power Down Control
multiple power supplies (switching or linear
Input Voltage Range of 2.7V to 5.5V
regulators). By staggering the startup sequence, it is
possible to avoid latch conditions or large in-rush
Small Footprint VSSOP-8 Package
currents that can affect the reliability of the system.
Low Quiescent Current of 80 µA
Available in VSSOP-8 package, the Power
Output Invert Feature
Sequencer contains a precision enable pin and three
Timing Controlled by Small Value External
open drain output flags. Upon enabling the LM3881,
Capacitor
the three output flags will sequentially release, after
individual time delays, permitting the connected
APPLICATIONS
power supplies to startup. The output flags will follow
a reverse sequence during power down to avoid latch
Multiple Supply Sequencing
conditions. Time delays are defined using an external
Microprocessor / Microcontroller Sequencing
capacitor and the output flag states can be inverted
FPGA Sequencing
by the user.
Typical Application Circuit Connection Diagram
Figure 1. Top View
VSSOP-8 Package
PIN DESCRIPTIONS
Pin # Name Function
1 VCC Input Supply
2 EN Precision Enable
3 GND Ground
4 INV Output Logic Invert
5 TADJ Timer Adjust
6 FLAG3 Open Drain Output #3
7 FLAG2 Open Drain Output #2
8 FLAG1 Open Drain Output #1
1
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
2All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Copyright © 2008–2013, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.

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