I have built the L297/298 as per the reference design by ST and it is fully functional in all but one respect, the resistors that go from ground to pins 1 and 15 on the L298 and pins 13 and 14 on the L297 have blown up quite spectacularily a few times now (but have also worked fine on other times) and I can't seem to figure out why. The datasheet for both the 298 and the 297 doesn't seem to offer any explainations as to what the function of these resistors is and what kinds of loads they are expected to handle, nor does it explain why they get hot enough to pop sometimes but not others.
My setup on this is enable tied to high, reset tied high, half/full tied to high, Vref going to center on a 500k voltage divider, control tied to ground and I'm using the reference values for the RC network that runs the chopper. I'm running EMC2. Anything I haven't listed is set to whatever the reference design calls for.
The reference design I am refering to is the very first result when you search "L297"
on google.
Any explaination as to what these resistors do or how to determine what the peak amps they use would be appreciated. Electronics and computer jargon doesn't phase me either, so don't worry about it. I just can't seem to figure out this chopper thing.
Regards, Matt