Controller pin protection

Discussion in 'General Electronics Chat' started by alphi, Nov 12, 2009.

  1. alphi

    Thread Starter New Member

    Jan 28, 2008
    9
    0
    What is the use of clamping diode at the pin of a controller

    regards,
    A
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
    Are you talking about adding an external discrete diode, or are you asking about the internal clamping diodes that are intrinsic in every CMOS input pin structure?
     
  3. alphi

    Thread Starter New Member

    Jan 28, 2008
    9
    0
    I am asking about the external diode
     
  4. Papabravo

    Expert

    Feb 24, 2006
    10,154
    1,795
    The purpose of a clamp is to restrict the voltage, that can be applied to a pin, to a convenient range. It does this by presenting a lower imepdance to voltage at an input pin than the impedance of the pin itself. As we know from Ohms law if current has two paths it can choose from then most of the current will pick the path with the lowest impedance.
     
Loading...