Introduction: Variable 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.
Features
- 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
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
Article source: http://bit.ly/2YshM5t
LM2576 Datasheet: https://www.onsemi.com/pub/Collateral/LM2576-D.PDF
LM358 Datasheet: https://www.onsemi.com/pub/Collateral/LM358-D.PDF
LM2576 Library: https://componentsearchengine.com/part-view/LM2576TV-ADJG/ON%20Semiconductor
LM358 Library: https://componentsearchengine.com/part.php?partID=671517
Altium Plugin: https://www.samacsys.com/altium-designer-library-instructions