[sdiy] Those AS33xx chips again...

[Roman]

It is clipped at the bottom because of the opamp used to boost the triangle vave. It's R-R supplied between GND and +15, so it clips whenever input goes negative. Now when you look a bit further to the " triangle low corner at high frequency " - those pics are taken from BEFORE opamp and here's the reason for clip. You can see that AS3340 apart from this crazy ringing goes slightly negative (see the arrow on the left side showing channel's reference GND level). As for CEM3340G, it does not go negative, and channel arrow is at the very bottom, so triangle goes about 20mV above GND and my opamp does not clip. Besides the low corner is uncomparably cleaner here.   Roman  Dnia 29 listopada 2017 00:12 Roman <rsdio at audiobanshee.com> napisał(a):  Great work! Thanks for sharing.   It's particularly interesting how the triangle wave is clipped on the bottom at high frequencies. Is this perhaps due to the power supply rails in your test circuit? In other words, could there be something external to the AS3340 that causes the clipping?   On the other hand, I don't think I see the clipping in the zoomed-in images of the triangle.   Brian    On Tue, Nov 28, 2017 at 2:34 PM, Roman <modular at go2.pl> wrote:  During few last days I've spent wonderful time with AS3340 VCO, giving it a  closer look, and also a few measurements. Nothing spectacular, just  something that any geeky nerd would find interesting.   It's about vintage chips, so it seems appropriate to have it written in  ancient vintage static html, basicaly the 90's style.  www.sowa.synth.net www.sowa.synth.net   Roman
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