So I'm a hobbyist mostly working with micro-controllers and simple low voltage digital circuits and I always thought the TIP120 transistor is a useless one for me because it has a Vce(sat) of around 2V. But yesterday I was testing it in a circuit and I realized that the Vce is actually way below that. So I got curious and read the datasheet again thinking maybe I had made a mistake and then I realized that Vce values are contradictory in it.
In the Electrical Characteristics table it states that Vce(sat) @ Ic=3A, Ib=12mA is 2 Volts (in the Max. column):
But further down in the Typical Performance Characteristics section you are presented this:
Here even the hfe is the same so at 3 Amps you have the same 12mA of base current that was specified in the table. But as you can see Vce is 1V here as opposed to the 2V stated in the table. And at 5 Amps it's ~1.3V as opposed to 4V(!) stated in the table.
So what's going on here exactly? 4V compared to 1.3V is a lot of difference. Is it because the table is stating the maximum? If so, what factor can cause Vce to change so much given that Ib and hfe are the same?