LT323A - 5 Volt, 3 Amp Voltage Regulator


  • Guaranteed 1% Initial Tolerance of Output Voltage
  • 3 Amp Output Current
  • 30 Watt
  • Full Internal Overload Protection
  • 100% Burn-in in Thermal Limit

Typical Application

LT323A Typical Application
LT323A Typical Application


The "K" Package has been Obsoleted

The LT123A/LT323A is an improved version of the popular LM123/LM323 5 Volt, 3 Amp Regulator. These new devices offer maximum initial output voltage tolerance of 1% and maintain a maximum tolerance of 3% over worst case operating conditions. Line and load regulation are also improved by a factor of 2. These tightened specifications ease design and application problems since safety margins are improved. Also, error budgets in other parts of the system can be expanded, and output voltages at the end of long supply runs can be more accurately maintained.The LT123A/LT323A incorporates Linear Technology's advanced design, process and test techniques for improved quality and reliability over similar device types. Specifically, all devices are burned in by shorting the output, thereby forcing the regulator into its current limit and eventually, thermal limit. This ensures that all device protection features are functional. A graph of the worst case output voltage, taking into account temperature, load and line variations, and power dissipation is shown below. For higher output current requirements, see the LT1003, 5V, 5A regulator data sheet.


CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LT323AT#PBF TO-220 T C 05-08-1420 Yes

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LT323AT#PBF TO-220 C $2.67 $2.35 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Click here to view our complete list of demo boards


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Design Tools

Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:

  • LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
  • LTpowerCAD - A complete power supply selection, synthesis and design tool
  • LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
  • PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
  • Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
  • LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
  • And More!

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