POP from my new L 298n chip... uh oh

Hello- first post! Great to be here.

I have a little card with an L 298n on it. I was feeding it a clock pulse from my arduino clone and it was working pretty well. But, I thought, maybe a bit slow with a 7.5 volt power supply. So I hooked up a laptop supply at 19.5 volts. The motor began to stutter and spin back and forth, because like a tool I had the interval between steps set to only 1 millisecond. It was working very smooth at 7 volts. But the higher voltage seemed to be too much. I should have dropped the interval when I upped the volts, clearly.

I did not let the magic smoke out, but I heard a POP and then no motion. So, my question is, did I fry my new L 298n chip, or might it be something else on the card?

Thanks

You should probably post a link or schematic of the device you were using. It is tough to say if "someone else on the card" was potentially destroyed without knowing what else is on the card.

Also, are you certain you connected the 19.5V power supply with the proper polarity?

Were you measuring the current and limiting it? Overcurrent could well have damaged the L298. Current limiting is important for motor control because a stalled motor can pull large currents.