PIC18F87K22 voltage regulator

Discussion in 'Embedded Systems and Microcontrollers' started by ahgan84, Apr 5, 2012.

  1. ahgan84

    Thread Starter Member

    Dec 19, 2011
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    Hi guys, I've been studying the datasheet of the PIC18F87K22 regarding its ENVREG pin which is the voltage regulator pin. I have some confusion here and I hope you guys can clarify for me. I'm migrating a PIC18F8722 design to this PIC18F87K22. The PIC18F8722 is using 5V voltage right? If I want to use 5V to power up the PIC18F87K22 too, does that means I have to enable the ENVREG pin?
     
  2. be80be

    Senior Member

    Jul 5, 2008
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  3. ahgan84

    Thread Starter Member

    Dec 19, 2011
    55
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    I'm using 5V. I don't use 3.3V.
    So, does this means I have to enable the ENVREG pin?
     
  4. be80be

    Senior Member

    Jul 5, 2008
    431
    57
    That chip runs on 3.3 volts it just has a built in regulator that has to be used if you board

    5 volt power read the page I posted if you looked you'll see the Circuit showing how to use this pin

    You hook it to Vdd if your powering from 5 volts
     
    Last edited: Apr 6, 2012
    ahgan84 likes this.
  5. ahgan84

    Thread Starter Member

    Dec 19, 2011
    55
    0
    Thanks.
    Another thing, there's regions on my PCB where 5V will be used and there are regions where 3.6V will be use. The input power supply I'm using is 24V. So, I'm planning to use LM2596-5.0 to produce the 5V and LM2596-ADJ to produce the 3.6V.
    The question is, should I use 5V(from LM2596-5.0) or 24V(from power supply) on the input voltage for LM2596-ADJ to produce 3.6V? Which voltage do you guys think is better?
     
    Last edited: Apr 9, 2012
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