How to Build an Adjustable Switching Power Supply Using LM2576 [Buck Converter, CC-CV]

Switching power supplies are known for high efficiency. An adjustable voltage/current supply is an interesting tool, which can be used in many applications such as a Lithium-ion/Lead-acid/NiCD-NiMH battery charger or a standalone power supply. In this article, we will learn to build a variable step-down buck converter using the popular LM2576-Adj chip.


  • Cheap and easy to build and use
  • Constant current and constant voltage adjustment [CC, CV] capability
  • 1.2V to 25V and 25mA to 3A controlling range
  • Easy to adjust the parameters (optimum use of variable resistors to control the voltage and current)
  • The design follows the EMC rules
  • It is easy to mount a heatsink on the LM2576
  • It uses a real shunt resistor (not a PCB track) to sense the current

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Step 1: Schematic

Step 2: PCB Layout

Step 3: A 3D/Real View of the Asemblde PCB Board

Step 4: Component Libraries (SamacSys)

Step 5: References

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    4 Discussions


    6 weeks ago

    Please tell me where I can buy the bare PCB board

    1 reply

    Reply 6 weeks ago

    Just check the main article source (I provided the link in the reference), You can read the full article there.
    At the bottom of the article there is a link where you can order the PCB, Good luck


    6 weeks ago

    A practical project with a PCB! nice.


    6 weeks ago

    Those library links are magic.