Basic Switch Mode PSU

This is a quick little project i have done which i find very useful.

This particular power supply uses the LM2576T-5.0 switch mode regulator to regulate a higher DC voltage down to 5v.

the circuit itself is nothing new and is straight from the manufactures datasheets, The circuit board is my work. The regulator itself is able to deliver upto 3A @ 5V and surprisingly you can still touch it, there is minimal heat produced by the regulator. The heatsink is there just incase but is not acutlly needed. (it does look cool aswell).

You may notice in the picture of the prototype that one of the capacitors is hanging slightly off of the board, this is a good example of forgetting how big some componets are before getting a prototype circuit board made. It all worked out well in the end and was not a waste. The updated PCB design has allowed for the capacitors to fit.

The circuit for this power supply can be seen below, as previousley stated this is straight from the manufacturers datasheet:

There is very little difference between this circuit and the one for the 1A model of the regulator also many of the other voltage ratings for this series of regulator use the same circuit, making this board suitable for many different regulators.

The PCB layout can be seen below:

The PCB layout took slightly longer than originally planned, this was due to not having footprints for the regulator and inductors. In the end i am very happy with out this has turned out.

Plans for updated versions include:

  • Varible Voltage SMPS
  • Extra filtering to reduce noise and ripple

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