3.3V is now widely used in electronic circuit projects (especially in digital electronics). These days several MCUs, CPUs and Digital interfaces (e.g: USB, Ethernet) uses 3.3V and in this project we developed suitable compact power supply unit for these projects. This project is mainly based on National Semiconductors LM1086-(3.3) power regulator.

With the suitable transformer this circuit may capable to deliver 3.3V (during the testing stages we get 3.29V) with 1.5A of maximum current. If you need more current please use LM1085 (3A) or LM1084 (5A) instead of LM1086 (U1).

Finalized version of 3.3V – 1.5A power supply unit
Finalized version of 3.3V – 1.5A power supply unit

To get the maximum performance, replace C2 and C3 with 10MFD/25V tantalum capacitors.

Please note that it is necessary to install good heatsink to the LM1086-3.3 (U1) regulator.

Project Related Downloads

Complete schematic and PCB diagrams of 3.3V – 1.5A Power Supply


LM1086 - 1.5A Low Dropout Positive Regulator