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  5. LT1129

Data Sheet
PDF
JP

Alternative Parts

LT3088
LT3088

800mA Single Resistor Rugged Linear Regulator

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LT1965

1.1A, Low Noise, Low Dropout Linear Regulator

Overview

Features and Benefits

  • 400mV Dropout Voltage
  • 700mA Output Current
  • 50μA Quiescent Current
  • No Protection Diodes Needed
  • Adjustable Output from 3.8V to 30V
  • 3.3V and 5V Fixed Output Voltages
  • Controlled Quiescent Current in Dropout
  • Shutdown
  • 16μA Quiescent Current in Shutdown
  • Stable with 3.3μF Output Capacitor
  • Reverse Battery Protection
  • No Reverse Output Current
  • Thermal Limiting
  • Surface Mount SOT-223 and DD-Pak Packages

Product Details

The LT1129/LT1129-3.3/LT1129-5 are micropower low dropout regulators with shutdown. The devices are capable of supplying 700mA of output current with a dropout voltage of 400mV at maximum output. Designed for use in battery-powered systems, the low quiescent current, 50μA operating and 16μA in shutdown, make them an ideal choice. The quiescent current does not rise in dropout as it does with many other low dropout PNP regulators.

Other features of the LT1129/LT1129-3.3/LT1129-5 include the ability to operate with small output capacitors. They are stable with only 3.3μF on the output while most older devices require between 10μF and 100μF for stability. Also the input may be connected to ground or a reverse voltage without reverse current flow from output to input. This makes the LT1129/LT1129-3.3/LT1129-5 ideal for backup power situations where the output is held high and the input is at ground or reversed. Under these conditions, only 16μA will flow from the output pin to ground. The devices are available in 5-lead TO-220, 5-lead DD-Pak and 3-lead SOT-223 packages.

Applications

  • Low Current Regulator
  • Regulator for Battery-Powered Systems
  • Post Regulator for Switching Supplies
  • 5V to 3.3V Logic Regulator

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Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Documentation & Resources

  • View All (9)
  • Data Sheets (1)
  • Reliability Data (1)
  • Application Notes (3)
  • Design Notes (3)
  • Solutions Bulletins & Brochures (1)
    • Document Type

    Tools & Simulations

    LTspice

    LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

    To launch ready-to-run LTspice demonstration circuits for this part:

    Step 1: Download and install LTspice on your computer.

    Step 2: Click on the link in the section below to download a demonstration circuit.

    Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.

    LTspice

    LTspice Simulations

    LT1129-5 Demo Circuit - Micropower Low Dropout Regulator with Shutdown (5.5-30V to 5V @ 500mA)

    Models for the following parts are available in LTspice:

    LT1129
    LT1129-3.3
    LT1129-5

    Product Recommendations

    LT1129 Companion Parts

    Recommended Related Parts

    Design Resources

    ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.

    Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
    LT1129CQ#PBF Material Declaration Reliability Data 5-Lead DD Pak
    LT1129CQ#TRPBF Material Declaration Reliability Data 5-Lead DD Pak
    LT1129CQ-3.3#PBF Material Declaration Reliability Data 5-Lead DD Pak
    LT1129CQ-3.3#TRPBF Material Declaration Reliability Data 5-Lead DD Pak
    LT1129CQ-5#PBF Material Declaration Reliability Data 5-Lead DD Pak
    LT1129CQ-5#TRPBF Material Declaration Reliability Data 5-Lead DD Pak
    LT1129CS8#PBF Material Declaration Reliability Data 8-Lead SOIC (Narrow 0.15 Inch)
    LT1129CS8#TRPBF Material Declaration Reliability Data 8-Lead SOIC (Narrow 0.15 Inch)
    LT1129CS8-3.3#PBF Material Declaration Reliability Data 8-Lead SOIC (Narrow 0.15 Inch)
    LT1129CS8-3.3#TRPBF Material Declaration Reliability Data 8-Lead SOIC (Narrow 0.15 Inch)
    LT1129CS8-5#PBF Material Declaration Reliability Data 8-Lead SOIC (Narrow 0.15 Inch)
    LT1129CS8-5#TRPBF Material Declaration Reliability Data 8-Lead SOIC (Narrow 0.15 Inch)
    LT1129CST-3.3#PBF Material Declaration Reliability Data 3-Lead SOT-223
    LT1129CST-3.3#TRPBF Material Declaration Reliability Data 3-Lead SOT-223
    LT1129CST-5#PBF Material Declaration Reliability Data 3-Lead SOT-223
    LT1129CST-5#TRPBF Material Declaration Reliability Data 3-Lead SOT-223
    LT1129CT#PBF Material Declaration Reliability Data 5-Lead TO-220
    LT1129CT-3.3#06PBF Material Declaration Reliability Data 5-Lead TO-220 (Flow 06)
    LT1129CT-3.3#PBF Material Declaration Reliability Data 5-Lead TO-220
    LT1129CT-5#06PBF Material Declaration Reliability Data 5-Lead TO-220 (Flow 06)
    LT1129CT-5#PBF Material Declaration Reliability Data 5-Lead TO-220
    LT1129IQ#PBF Material Declaration Reliability Data 5-Lead DD Pak
    LT1129IQ#TRPBF Material Declaration Reliability Data 5-Lead DD Pak
    LT1129IQ-3.3#PBF Material Declaration Reliability Data 5-Lead DD Pak
    LT1129IQ-3.3#TRPBF Material Declaration Reliability Data 5-Lead DD Pak
    LT1129IQ-5#PBF Material Declaration Reliability Data 5-Lead DD Pak
    LT1129IQ-5#TRPBF Material Declaration Reliability Data 5-Lead DD Pak
    LT1129IS8#PBF Material Declaration Reliability Data 8-Lead SOIC (Narrow 0.15 Inch)
    LT1129IS8#TRPBF Material Declaration Reliability Data 8-Lead SOIC (Narrow 0.15 Inch)
    LT1129IS8-3.3#PBF Material Declaration Reliability Data 8-Lead SOIC (Narrow 0.15 Inch)
    LT1129IS8-3.3#TRPBF Material Declaration Reliability Data 8-Lead SOIC (Narrow 0.15 Inch)
    LT1129IS8-5#PBF Material Declaration Reliability Data 8-Lead SOIC (Narrow 0.15 Inch)
    LT1129IS8-5#TRPBF Material Declaration Reliability Data 8-Lead SOIC (Narrow 0.15 Inch)
    LT1129IST-3.3#PBF Material Declaration Reliability Data 3-Lead SOT-223
    LT1129IST-3.3#TRPBF Material Declaration Reliability Data 3-Lead SOT-223
    LT1129IST-5#PBF Material Declaration Reliability Data 3-Lead SOT-223
    LT1129IST-5#TRPBF Material Declaration Reliability Data 3-Lead SOT-223
    LT1129IT#06PBF Material Declaration Reliability Data 5-Lead TO-220 (Flow 06)
    LT1129IT#PBF Material Declaration Reliability Data 5-Lead TO-220
    LT1129IT-3.3#PBF Material Declaration Reliability Data 5-Lead TO-220
    LT1129IT-5#06PBF Material Declaration Reliability Data 5-Lead TO-220 (Flow 06)
    LT1129IT-5#PBF Material Declaration Reliability Data 5-Lead TO-220
    LT1129MPST-3.3#PBF Material Declaration Reliability Data 3-Lead SOT-223
    LT1129MPST-3.3#TRPBF Material Declaration Reliability Data 3-Lead SOT-223
    Wafer Fabrication Data R086 Reliability Data

    PCN-PDN Information

    Select a model from the dropdown below to subscribe to PCN/PDN notifications and view past notifications as well.

    Select Model for PCN Information
    • LT1129CQ#PBF Production
    • LT1129CQ#TRPBF Production
    • LT1129CQ-3.3#PBF Production
    • LT1129CQ-3.3#TRPBF Production
    • LT1129CQ-5#PBF Production
    • LT1129CQ-5#TRPBF Production
    • LT1129CS8#PBF Production
    • LT1129CS8#TRPBF Production
    • LT1129CS8-3.3#PBF Production
    • LT1129CS8-3.3#TRPBF Production
    • LT1129CS8-5#PBF Production
    • LT1129CS8-5#TRPBF Production
    • LT1129CT#PBF Production
    • LT1129CT-3.3#06PBF Production
    • LT1129CT-3.3#PBF Production
    • LT1129CT-5#06PBF Production
    • LT1129CT-5#PBF Production
    • LT1129IQ#PBF Production
    • LT1129IQ#TRPBF Production
    • LT1129IQ-3.3#PBF Production
    • LT1129IQ-3.3#TRPBF Production
    • LT1129IQ-5#PBF Production
    • LT1129IQ-5#TRPBF Production
    • LT1129IS8#PBF Production
    • LT1129IS8#TRPBF Production
    • LT1129IS8-3.3#PBF Production
    • LT1129IS8-3.3#TRPBF Production
    • LT1129IS8-5#PBF Production
    • LT1129IS8-5#TRPBF Production
    • LT1129IT#06PBF Production
    • LT1129IT#PBF Production
    • LT1129IT-3.3#PBF Production
    • LT1129IT-5#06PBF Production
    • LT1129IT-5#PBF Production

    Support & Discussions

    LT1129 Discussions

    RE: Will the LT1129-5 output be stable with ceramic output capacitors?
    RE: Thermal Resistance for LT1129 Junction to Case for DDPak package.
    All LT1129 Discussions
    LT1129 Contact ADI Technical Support »
    LT1129 Ask your question »
    LT1129 Contact ADI Technical Support » LT1129 Ask your question »

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