Measure 100% Rise Time

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Zalgo
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Joined: Mon Nov 25, 2019 9:29 am

Measure 100% Rise Time

Post by Zalgo »

Hello, is there any way to measure 100% rise time, instead of the 90/10 or 80/20 currently available?

Gerry
PICO STAFF
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Posts: 1145
Joined: Mon Aug 11, 2014 11:14 am

Re: Measure 100% Rise Time

Post by Gerry »

Hi Zalgo,

Not automatically using our measurement tools, which provide you with the 2 standard values of Rise Time measurement. There isn't a 0/100% Rise Time standard because it can take a disproportionately long time to converge on the 100% value of the input waveform (in some cases you may not actually get to the true 100% value if for example the sample rate is too small for the width of the pulse, and in other cases you may not be able to tell if you actually have the true 100% value).

However, you can measure it manually, as shown in the example image and, as you can see, the 100% point is so far removed from the rising edge of the signal, that it almost seems unrelated (and in this case the waveform is hugely oversampled, i.e. 1GS/s for a 1kHz waveform, so the 100% maximum value has been correctly captured and displayed).
0-100 Rise Time.png
Regards,

Gerry
Gerry
Technical Specialist

Zalgo
Newbie
Posts: 0
Joined: Mon Nov 25, 2019 9:29 am

Re: Measure 100% Rise Time

Post by Zalgo »

Gerry wrote:
Tue Nov 26, 2019 11:35 am
Hi Zalgo,

Not automatically using our measurement tools, which provide you with the 2 standard values of Rise Time measurement. There isn't a 0/100% Rise Time standard because it can take a disproportionately long time to converge on the 100% value of the input waveform (in some cases you may not actually get to the true 100% value if for example the sample rate is too small for the width of the pulse, and in other cases you may not be able to tell if you actually have the true 100% value).

However, you can measure it manually, as shown in the example image and, as you can see, the 100% point is so far removed from the rising edge of the signal, that it almost seems unrelated (and in this case the waveform is hugely oversampled, i.e. 1GS/s for a 1kHz waveform, so the 100% maximum value has been correctly captured and displayed).

0-100 Rise Time.png
Regards,

Gerry
Thanks. Yes I can already measure it manually, but was hoping there was a way to do it automatically. I need to take hundreds of samples for the project I'm working on so manually is not really an option.

Gerry
PICO STAFF
PICO STAFF
Posts: 1145
Joined: Mon Aug 11, 2014 11:14 am

Re: Measure 100% Rise Time

Post by Gerry »

Hi Zalgo,

Can I ask why you need a 0 to 100% Rise Time measurement, as opposed to, say, a 1% to 99% Rise Time measurement (especially as a 0% to 100% rise time for an over-damped 2nd order system is infinite)?

Regards,

Gerry
Gerry
Technical Specialist

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