Re: L298 goes boom on my camtronics :(

Hi all,
Firstly, great list! this is my first message after many months of
silent participation.
I played around with l297 / l298 combination a few years back and
after much smoke and lots of research became very suspicious of the
role the l297 plays in these failures. One of the members here
mentioned main power supply glitches while running were enough to
ping his drives. I can confirm I experienced similar behaviour in a
prototype situation, if the L297 was handling pulse and direction
signals and power removed from it the next power up would smoke the
L298 even with no load attached! I found a number of notes at the
time which mentioned there was an inherent latch-up problem with the
l297 / L298 combination if they were not left in a certain state
prior to power down, which caused problems on next power up. I knew
this didn't make good electrical sense at all, the L297 is simply the
driver but it most certainly did seem to happen.
I then reverted to running my l298's directly from an embedded
microprocessor with L298 signals controlled in software and well, as
long as I disabled all drives to the l298 prior to power down no
problems. But if I did not, next power up, smoke. So maybe it was
really the l298 that had the latch problem?
I never conclusively solved this, but it motivated me to start
building my own discrete drives with a good degree of success.
In concluding I think there are two issues which seem to be
affecting the reliability of this combination, both snubber problems
and some type of latch up issue in the 298. Cause or effect? I still
do not know!
Kind Regards, John Kooloos