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LM3880 Power Sequencer
September 2006
LM3880 Power Sequencer
General Description
The LM3880 Power...
www.DataSheet4U.com
LM3880 Power Sequencer
September 2006
LM3880 Power Sequencer
General Description
The LM3880 Power Sequencer offers the easiest method to control power up and power down of multiple power supplies (switchers 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 a SOT23-6 package, the Power Sequencer contains a precision enable pin and three open drain output flags. Upon enabling the LM3880 the three output flags will sequentially release, after individual time delays, permitting the connected power supplies to startup. The output flags will follow a reverse sequence during power down to avoid latch conditions. Standard timing option of 30ms is available. EPROM capability allows every delay and sequence to be fully adjustable. Contact National Semiconductor if a nonstandard configuration is required.
Features
n n n n n n n Easiest method to sequence rails Power up and power down control Input voltage range of 2.7V to 5.5V Small footprint SOT23-6 Low quiescent current of 20 µA Standard timing options available Customization of timing and sequence available through factory programmability
Applications
n Multiple supply sequencing n Microprocessor / Microcontroller sequencing n FPGA sequencing
Typical Application Circuit
20192601
© 2006 National Semiconductor Corporation
DS201926
www.national.com
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