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Homework Help: Op-amp as a comparator

  1. Jan 17, 2009 #1
    Hi, I'm sorry I can't follow the recommended structure for this, as it's not a problem as such, more of a 'what should I have got?'

    I have to write up a lab report in which we were using Op-Amps as summing amplifiers, comparators and integrators. We used an open loop 741 as the comparator, referenced to ground. A sine wave input signal was passed through the non-inverting input, and the output resembled a square wave. Now, we were meant to increase the frequency of the input signal to see what would happen to the output, but we didn't get this far in the experiment. I know a little about slew rate limiting, and I'm assuming this is where the answer lies. Am I right in saying that at a certain frequency the output would resemble a triangle wave, as there is not enough time for the output to saturate before the input crosses the reference again?

    Thank you for your help.
  2. jcsd
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