[bb88]

> All you have to do is read the datasheet and multiply a few numbers to calculate worst-case power.

True story: When I was in college the lab mate I had reversed unknowingly reversed power and ground on a chip on a breadboard. I turned off the circuit and reached for the chip and got a blister on my finger.

Maximum power is infinite in that case (well not infinite, but pretty damn high!) I don't recall seeing a data sheet on power consumption when power and ground is reversed...

No offense, but this comes across as "This was the way I was forced to learn it, and dang it everyone else should do the same." But my experience says, I wouldn't have got a blister on my finger if I had that.

[mindslight]

Current was flowing through the "body diode" which is intrinsic to the construction of ICs (it's normally reverse biased). The forward voltage was likely around 0.6v, maybe a little higher with a lot of current flowing through it. So roughly that times however many amps the power supply could supply with the resistance of the leads/rails. It doesn't actually take that much power to make a DIP package extremely hot though, lacking any sort of heat sink.

[nunuvit]

I can't edit the comment now, but I worded it wrong. The quote only applies to exceeding maximum values. The visualization is much more useful if you've calculated worst-case. I use a thermal camera all the time.