The Different Ways To Look at Negative Resistance

[lcamtuf] has an in-depth look at the concept of negative resistance that goes somewhat further than one might expect. Normally, as voltage across a resistance increases so too does the …. The Different Ways To Look at Negative Resistance.

Negative resistance is the concept of current decreasing as voltage increases. But beyond the raw concept, there are a few other ways to look at this idea. The usual way to think about it is negative differential resistance (NDR).

Not everything has a linear relationship between voltage and current, and for a device to exhibit NDR means that in certain ranges the I–V curve actually slopes downward; increasing one of voltage or current decreases the other. Once they are glowing, increasing current can result in decreasing voltage. True negative resistance, that of a literal -100 Ω resistor, does not exist.