Mac book pro ringing?

[stratus46]

Sorry, I should have been clearer and put in a quote. I was referring to Tom's suggestion that Trondareo's square wave ring looked like an impedance mismatch and that he could try testing it by using properly terminated co-ax. I was interested to know if Trondareo tried it and what the results were.

It's not a bad DAC or bad filters or impedance mismatch. You can't make squarewaves in severely band limited sampled systems. As the sample rate goes up, the number of 'components' of your square wave increases and the ring duration shortens and the ring amplitude reduces but it never goes away. What interested me is the asymmetry of the ringing. It should be the same at both transitions. Looks like some group delay.

G²

 

[tomchr]

I'm starting to appreciate the $100 I spent on my HP 3312A function generator.... 🙂
DC~13 MHz square, sine, triangle. The sine generator is the usually triangle generator followed by a sine shaper circuit, but the THD is still below 1 %. Fine for basic testing, but of course not for THD measurements.

~Tom