By: David W. Hess (dwhess.delete@this.banishedsouls.org), September 27, 2007 3:21 am
Room: Moderated Discussions
Jonathan Kang (johnbk@gmail.com) on 9/26/07 wrote:
---------------------------
>Transistors in non-saturation switch a lot faster than going back and forth between
>active and inactive regions. This is especially true for current-steering logic.
>The problem is you open yourself up to be much more sensitive to noise and latch-up problems.
I completely agree. At the time I ran across this, ECL was not that common (if it ever could be considered such) and the comparator in question was not a latching comparator making it unusual given its speed.
Why would latch-up be an additional problem? Isn't that just an aspect of circuit design and process? I have only had to deal with it in old op-amp and comparator designs as well as CMOS processes that suffer from their parasitic SCR structure.
Testing fast devices is actually more difficult from one perspective because parts like tunnel diodes which can be used in fast pulse generators have gotten much more difficult to find. The replacement in these applications is naturally the emitter coupled multivibrator.
---------------------------
>Transistors in non-saturation switch a lot faster than going back and forth between
>active and inactive regions. This is especially true for current-steering logic.
>The problem is you open yourself up to be much more sensitive to noise and latch-up problems.
I completely agree. At the time I ran across this, ECL was not that common (if it ever could be considered such) and the comparator in question was not a latching comparator making it unusual given its speed.
Why would latch-up be an additional problem? Isn't that just an aspect of circuit design and process? I have only had to deal with it in old op-amp and comparator designs as well as CMOS processes that suffer from their parasitic SCR structure.
Testing fast devices is actually more difficult from one perspective because parts like tunnel diodes which can be used in fast pulse generators have gotten much more difficult to find. The replacement in these applications is naturally the emitter coupled multivibrator.
