Operational amplifier Jitter

Discussion in 'General Electronics Chat' started by Kaspars, Jun 20, 2011.

  1. Kaspars

    Thread Starter New Member

    Jun 9, 2011
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    Hi,

    Can someone suggest me real Operational amplifier with as small as possible Jitter?

    My OP works in comparator mode and I need low jitter Operational Amplifier so the edge deviation would be as small as possible.

    Thnaks :)
     
  2. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    Op amps make inferior comparators. You will get lower jitter from a real high speed comparator.
    What is your application?
     
  3. Jaguarjoe

    Active Member

    Apr 7, 2010
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    Are you saying you get jitter when the output switches from one state to the other? If so, you need a hysteresis resistor added between the output and the (+) input. Usually, it's a high value, like 100k.
    Because of their internal compensating capacitor op-amp comparators are very slow. An LM339 is a very common comparator chip. Beware that it has an open collector output requiring an external pull up resistor. Also note that its output current capacity is low.
     
  4. Kaspars

    Thread Starter New Member

    Jun 9, 2011
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    My application is Asynchronous Sigma Delta modulator with hysteresis:

    [​IMG]

    Where I use AD8056 operation amplifiers with slew rate 1400V/us.

    So I want jitter effect as small as it could be, becouse ASDM resolution depends on switch time accuracy.

    [​IMG]
     
  5. Jaguarjoe

    Active Member

    Apr 7, 2010
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  6. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    Last edited: Jun 21, 2011
  7. beenthere

    Retired Moderator

    Apr 20, 2004
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