[sdiy] need an op-amp that can clip without phase reversal

Jason Proctor jason at redfish.net
Thu Aug 14 09:43:35 CEST 2008


i'm late to this thread, a newbie, and drunk into the bargain, but 
for railsafe operation, the LT1013 seems to be the opamp of choice 
IIRC.



>  > I did try the the TL072 which supposedly does not latch up... 
>well it did, and a whole lot.
>
>The TL072 doesn't latch up. However, if the circuit uses negative 
>feedback it may appear to do so. Since the TL072 undergoes phase 
>reversal when the input gets too close to the negative rail, 
>negative feedback becomes positive feedback and the whole circuit 
>slams to the rail.
>
>For example, an SVF built with the TL072 as voltage followers can 
>show this effect on power up.
>
>If you use two inverting gain stages you will avoid this problem. 
>But this may not an option for you. Reducing the input voltage range 
>is usually the best in this case.
>
>Tony
>
>www.oakleysound.com
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