1. spinnaker

    Thread Starter AAC Fanatic!

    Oct 29, 2009
    I have a Pic18F47J53. It has a pin called VDDCORE

    The PIC18F47J53 family of devices provides an on-chip voltage regulator to supply the correct voltage levels to the core. Parts designated with an “F” part number (such as PIC18F47J53) have the voltage regulator enabled. These parts can run from 2.15V-3.6V on VDD, but should have the VDDCORE pin connected to VSS through alow-ESR capacitor.

    It looks like this is a regulator output. Why would I need that? Shouldn't I be supplying a regulated voltage already? Or do I misunderstand.

    What is "the core".

    It calls for a cap on that pin. Do I need it if I am not using that ourput?
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    A relatively lower supply voltage lets things run faster while not running as hot as they might with a higher supply voltage.

    The "core" is the middle where all the interesting things happen. It's where the "w" register lives, among other wonderful things. With a split supply the "guts" run on a lower voltage (<2.7V) while the I/O pins run on up to 3.6V.

    Put that cap on that pin, you *are* using that output to filter the core voltage.
  3. takao21203

    AAC Fanatic!

    Apr 28, 2012
    You need to connect a cap. It also works with regular capacitors.
    But for best results, use a 1uF ceramic cap.
  4. spinnaker

    Thread Starter AAC Fanatic!

    Oct 29, 2009
    So just a cap from that pin to ground?
  5. JohnInTX


    Jun 26, 2012
    Should be everything you need to get it going.