RE: [CAD_CAM_EDM_DRO] L298 smoking

It could be the L297 but I would suspect a few other things first.
Check that you have about 20Khz on pin 1 if not then either the L297 is
bad, the oscillator is grounded or not connected properly. Check that
your oscillator uses a 3300 pf ceramic cap and a 22k resistor connected
to the proper pins of the L298
Or:
You may have Vref set incorrectly in that you have everything connected
properly but your Vref is set to high not causing a short circuit but an
overload.
Dan