Regulator chip ground pin cut off why?

Discussion in 'General Electronics Chat' started by harrison2015, Apr 22, 2015.

  1. harrison2015

    Thread Starter Member

    Apr 22, 2015
    80
    0
    Some circuit I have come across cut off the ground pin of regulators, why would a circuit not want a regulator ground pin to be used? any reasons why
     
  2. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
    5,699
    905
    The center pin is often connected to the tab:
    upload_2015-4-22_23-0-23.png upload_2015-4-22_23-3-42.png

    Is that what you are calling the "ground" pin? What regulator are you using?

    Cutting the center pin off and using the tab is just an alternative way to connect.

    John
     
  3. harrison2015

    Thread Starter Member

    Apr 22, 2015
    80
    0
    Regulator chips
    AMS1117
    LD33
    FA22
    LD1117A
    D113EE
    D112FB
    AME1084

    Why would they want to use the tab instead of the center pin?
     
  4. harrison2015

    Thread Starter Member

    Apr 22, 2015
    80
    0
    Some regulators center pin is V out and other regulators center pin is Ground

    How can you use the same circuit and just change regulator that has a center pin as V out and use a regulator that has a center pin as ground?

    It won't work, but what would you have to do to the circuit to so you can use either types of regulator pin configurations?
     
  5. gerty

    AAC Fanatic!

    Aug 30, 2007
    1,153
    304
    Another reason is to make more room around the now 2 pin connection, less cluttered.
     
  6. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    because the regulator would fit in a to3 socket that way.
     
  7. harrison2015

    Thread Starter Member

    Apr 22, 2015
    80
    0
    Yes the regulator will fit in a 3 pin socket but the center pin is either a V out or Ground pin

    I can't take a regulator that has a center pin V out and replace it with a regulator with a center pin that is a ground pin
    Is there a way to use either types of regulators without modifying the PCB board?

    The Tab is either ground or V out
     
  8. #12

    Expert

    Nov 30, 2010
    16,316
    6,818
    You answered your own question, then typed the question.
    You can't replace a regulator with a different pinout without changing the circuit board it connects to.
     
  9. ian field

    Distinguished Member

    Oct 27, 2012
    4,415
    784
    Use a TO220 insulating kit and hand wire any pins that don't match the pad layout.
     
Loading...