Now a days 3.3V PSU is essential for microcontroller, programmable logic devices and for some analog components also (especially with some new ADCs). This is ultra-simple 3.3V power supply unit, which is suitable for above mentioned experiments. This power supply is based on, ON semiconductor’s MC33269T-3.3 LDO regulator and it is capable to deliver 3.3V output with maximum of 800mA current.

The PCB design supplied with this article is also compatible with LD1117#33 (also known as LD33V) LDO regulator and it can use with this PCB without any changes. Dimension of the given PCB is 70mm × 35mm and it is design with all through-hole components.

Maximum input voltage for this module is 20V (DC) for MC33269T-3.3 and 15V (DC) for LD1117#33 (or LD33V). In our unit we use 230V - 9V (1A) step down transformer as AC input for this unit.

Project Related Downloads

Schematic and PCB design for 3.3V Power Supply Unit.


MC33269 - 800 mA Low Dropout Voltage Regulator
LD1117 - Low Drop Fixed Positive Voltage Regulator

See Also

3.3V - 1.5A Compact Power Supply Unit