); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] Dr Bruce Griffiths wrote: > ); SAEximRunCond expanded to false > Errors-To: [EMAIL PROTECTED] > > Pete wrote: >> ); SAEximRunCond expanded to false >> Errors-To: [EMAIL PROTECTED] >> >> Magnus, >> >> This discussion is why I have allowed the ADA4899-1 to saturate in the ZCD >> posted earlier. The transition times up & down in the second stage are 350 >> to >> 400 ns; thus I believe the <50ns overload recovery doesn't degrade the >> measured jitter. With 500MHz 'scope bandwidth, the 1KHz squarewave >> output has <1% over/under shoot & appears noise free at the zero crossing. >> >> The output transitions are fast enough for my HP 5370A to show < 1ns >> jitter over 1K or 10K samples. >> >> Regards, >> >> Pete Rawson >> > Pete > > What about the power supply noise that appears at the amplifier output > during saturation? > Power supply noise is almost always much larger than the opamp input noise. > A simple resistor + diode clamp in addition to the feedback clamp will > easily attenuate the output noise of an opamp with diode clamps across > its feedback resistor.
The output of an opamp is always referenced to its power supply, regardless of the configuration. If the power supply is noisy, the output is noisy. -Chuck Harris _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
