SNVS555D January   2008  – December 2014 LM3881

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Handling Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Adjustable Timing
      2. 7.3.2 Enable Circuit
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power Up with EN Pin
      2. 7.4.2 Power Down with EN Pin
      3. 7.4.3 Noninverted Output Mode
      4. 7.4.4 Inverted Output Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Open-Drain Flags Pullup
      2. 8.1.2 Enable the Device
      3. 8.1.3 Timing Adjust
    2. 8.2 Typical Application
      1. 8.2.1 Simple Sequencing of Three Power Supplies
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Sequencing Using Independent Flag Supply
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

1 Features

  • 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.

Typical System Application

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