Ripple measurement

[gireesh]

I am having a high freq DC-DC converter. I need to measure ac ripple (peak to peak) using an oscilloscope of any make. How to program it. Having tktds & hioki drivers. Spike measurement I programmed it.

[Dennis_Knutson]

What have you tried? This is generally a basic measurement. AC couple the signal and measure peak to peak.

"Spike measurement I programmed it." does not mean anything to me.

[gireesh]

In DC-DC converter main issue is ripples only. It makes so many problems, when the load is an inductive. So we should measure the ripple. For spike measurement, we can easily findout the pk-pk. In the oscilloscope there is a function : pk-pk. It gives the pk-pk. But for the ripple is not any function. So we have to seperate the ac component first. Then take the pk-pk of that. Normally we can see the ripple at 10micro-sec time/div. Spike at 1micro-sec. My question was how to seperate/measure it?

[Dennis_Knutson]

What don't you understand about ac coupling the signal?

[gireesh]

Beg your pardon

[gireesh]

Beg your pardon

[Dennis_Knutson]

Perhaps you need to study some of the oscilloscope basics if you don't know how to dc or ac couple the scope's inputs. Read your manual.

Your statement "we have to seperate the ac component" means you need to remove the dc component and that is what the ac coupling switch/knob on the scope does.

[gireesh]

That I am not specifically told. normally ripples measured in ac coupling mode only, that everyone know. Even ac coupling mode also it will show some spikes over the ripple. If I am take pk-pk function, it will measure that spikes pk-pk. I need the exact ripple, then only pk-pk function will measure the exact ripple. I used cursor for that, but o/p to o/p it will vary. So that also not a better solution.

[Dennis_Knutson]

I think I understand now what you are saying. You have some additional high values that you don't think should be considered as ripple?

[gireesh]

yes it is

how to measure the ripple in its actual form.

I think it is very difficult to measure. But nothing is impossible. have to try a lot. based on frequency or filter can we measure?