Single supply op amp

Discussion in 'General Electronics Chat' started by sirch2, Feb 3, 2014.

  1. sirch2

    Thread Starter Well-Known Member

    Jan 21, 2013
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    I've never used a single supply Op Amp. Is there any reason I can't use a MCP6001 (datasheet - http://ww1.microchip.com/downloads/en/DeviceDoc/21733j.pdf) as a Schmitt trigger for a 40kHz signal?

    What I'm aiming to do is measure the phase difference between a transmitted and received ultrasonic signal. The output of the Schmitt trigger would be fed to a MCU which would time the difference between the two signals.
     
  2. Wendy

    Moderator

    Mar 24, 2008
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  3. ronv

    AAC Fanatic!

    Nov 12, 2008
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    It might be a little slow if you are trying to do what I think you are trying to do. A comparator with some hysteresis might be better.
     
  4. crutschow

    Expert

    Mar 14, 2008
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    At that frequency you definitely want to use a comparator as a Schmitt trigger, not an op amp which will give a slow response time.
     
  5. LvW

    Active Member

    Jun 13, 2013
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    Yes - I agree with Crutschow, mainly because of the rather slow slew rate of the amplifier (only 0.6V/µs).
     
  6. t06afre

    AAC Fanatic!

    May 11, 2009
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    If you drive an opamp into saturation, it will need some time to get out of that saturation mode. That is one of reasons you really do not want to use a opamp as a comparator
     
  7. sirch2

    Thread Starter Well-Known Member

    Jan 21, 2013
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    Thanks for the replies. I'll do some research on comparators, I'm looking to ideally drive the whole thing at 3.3V but 5 to 6V could be an option, hence the reason I was looking at that Op Amp.
     
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