Jumpering IC pins

  • I have a bit of an issue. I’d like to replace the voltage regulator on an 5v Arduino with a 3.3v regulator. Both are 5 pin and the input on both is the same pin (pin number 1). 2, 3 and 4 are also unused on the 5v with the output on pin 5. My problem is that on my regulators the output pin is 4 and 5 is unused. In this case can you just jumper pin 4 and 5 with a small wire on the new regulator since 5 is unused but on the PCB that is where the output needs to be?

  • Mod

    @thecricketer I’d say it depends on the layout of the pcb (does pin 4 go anywhere?), and the specifications of the regulator (does it allow to put 3.3V on pin 5?).

  • Well the replacement regulator datasheet says that pin 5 its not connected to anything so I'm assuming that it doesn't matter. With regard to the PCB, I don't know the answer to that and didn't really consider that. I don't have the actual schematic but my understanding is that all Arduino Mini Pro's are made from the same schematic so if so, pin 4 per the schematic is "bypass" and is not attached to anything on the PCB.