LM3881 Power Sequencer
February 6, 2008
LM3881 Power Sequencer
General Description
The LM3881 Power Sequencer offers t...
LM3881 Power Sequencer
February 6, 2008
LM3881 Power Sequencer
General Description
The LM3881 Power Sequencer offers the easiest method to control power up and power down of multiple power supplies (switching or linear
regulators). 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 MSOP-8 package, the Power Sequencer contains a precision enable pin and three open drain output flags. Upon enabling the LM3881, the three output flags will sequentially release, after individual time delays, permitting the www.DataSheet4U.com connected power supplies to startup. 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.
Features
■ ■ ■ ■ ■ ■ ■
Easiest method to sequence rails Power up and power down control Input voltage range of 2.7V to 5.5V Small footprint MSOP-8 package Low quiescent current of 80 µA Output invert feature Timing controlled by small value external capacitor
Applications
■ Multiple Supply Sequencing ■ Microprocessor / Microcontroller Sequencing ■ FPGA Sequencing
Typical Application Circuit
30048401
© 2008 National Semiconductor Corporation
300484
www.national.com
LM3881
Connection Diagram
30048402
Top View MSOP-8 Package
Ordering Information
Order Number
www.DataSheet4U.com LM3881MM
Package Type MSOP...