1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

Zener,Diode,what Dif?

Discussion in 'General Electronics Chat' started by Muhammad89, Aug 30, 2008.

  1. Muhammad89

    Muhammad89 New Member

    Joined:
    Aug 19, 2008
    Messages:
    82
    Likes:
    0
    a zener-diode is typically used as a regulator where a simple diode is used as a rectifier, what makes that difference?what is the sth in both junctions that creates this difference? can azener be used as a rectifier? and why cant a diode be used as a regulator?


    Muhammad89:D
     
  2. audioguru

    audioguru Well-Known Member Most Helpful Member

    Joined:
    Mar 16, 2004
    Messages:
    32,435
    Likes:
    933
    Location:
    Canada, of course!
    ONLINE
    A zener diode is designed to break down at its rated reverse voltage.
    A rectifier diode has a high rated reverse voltage.

    Both are diodes so both can be forward biased rectifiers if the voltage is low for the zener diode.
     
  3. Diver300

    Diver300 Well-Known Member

    Joined:
    Oct 19, 2007
    Messages:
    3,062
    Likes:
    101
    Location:
    England
    In the forward direction a diode behaves just like a zener diode.

    In the reverse direction a zener diode will conduct at the zener voltage. The zener voltage is known and within certain limits. The zener voltage does not change much with current and making the zener diode conduct like that won't damage it as long as it doesn't get to hot.

    In the reverse direction and ordinary diode will not conduct up to its breakdown voltage. The breakdown voltage may vary a lot within one type of diode. It will also vary a lot with current, and making the diode break down may damage it.

    In short, use diodes in the way that they were meant to be used.

    I don't know what is inside a zener that makes it work the way it does.
     
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. Willbe

    Willbe New Member

    Joined:
    Aug 16, 2008
    Messages:
    1,236
    Likes:
    7
    Location:
    MD

    http://en.wikipedia.org/wiki/Zener_diode

    "In a 5.6 V [Zener] diode, the two effects occur together and their temperature coefficients neatly cancel each other out, thus the 5.6 V diode is the component of choice in temperature-critical applications."

    http://en.wikipedia.org/wiki/Avalanche_breakdown
     
    Last edited: Aug 30, 2008
  6. crutschow

    crutschow Well-Known Member Most Helpful Member

    Joined:
    Mar 14, 2008
    Messages:
    10,592
    Likes:
    477
    Location:
    L.A., USA Zulu -8
    ONLINE
    A rectifier diode junction is doped in a manner to give a high breakdown voltage, and they are designed to break down above their rated value. A zener diode junction is doped to provide a controlled and lower voltage breakdown at a specified voltage. It's related to the doping profiles and magnitude of doping at the PN junction.
     
  7. Muhammad89

    Muhammad89 New Member

    Joined:
    Aug 19, 2008
    Messages:
    82
    Likes:
    0
    Ooooh, I can tel!:D
     
  8. architmh

    architmh New Member

    Joined:
    Sep 2, 2008
    Messages:
    8
    Likes:
    0
    crutschow is right.the diff in characteristics are totally dependent on doping level... zener diode is a reverse biased heavily-doped PN junction diode operated in the breakdown region only...tats y it is not used as a regulator...:)
     

Share This Page