getting error on negative clipping

Discussion in 'General Electronics Chat' started by bhuvanesh, Jul 4, 2014.

  1. bhuvanesh

    Thread Starter Member

    Aug 10, 2013
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    i am getting 0.7 error on negative clipping.Is there any possible modification that we can make to the below circuit to eliminate that error 0.7v.
     
  2. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    You could use a shottky diode, which should have only 0.3V drop.
     
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  3. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Or you could connect the diode cathode (not the input signal) to -0.7V instead of ground.
     
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  4. bhuvanesh

    Thread Starter Member

    Aug 10, 2013
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    Any other idea to minimize the lose still more.i mean to reduce the loss less than 0.3
     
  5. bhuvanesh

    Thread Starter Member

    Aug 10, 2013
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    Super Alec_t.This is what i want.does adding the negative 0.7v volt make any bad things to circuits.
     
  6. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Which circuits?
     
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  7. bhuvanesh

    Thread Starter Member

    Aug 10, 2013
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    i mean to the whole clipper circuit
     
  8. crutschow

    Expert

    Mar 14, 2008
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    How much offset from 0V can you tolerate since no circuit can do the clipping perfectly?
     
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  9. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    If "the whole clipper circuit" is the one in post #1 then the answer is "no".
     
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  10. crutschow

    Expert

    Mar 14, 2008
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    If you want the clamp voltage down to a few mV of zero than you can use a half-wave precision rectifier circuit using an opamp and a diode, as long as the highest frequency is withing the bandwidth of the opamp. With that the negative clamp voltage will be basically within the input offset voltage of the selected opamp.

    Below is a simulation of two circuits, one a compensated diode and the other a precision rectifier clamp. The compensated circuit shows a rounded clamp with a peak offset of about 108mV. The precision rectifier circuit has a flat clamp with about 2mV offset (the opamp input offset).

    Clamp.gif
     
    Last edited: Jul 4, 2014
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