Hi all, I am confused as to how to determine the power dissipated in a Darlington array. Take for example the ULN2068 array. It is rated as quad 1.5a. I know that the maximum current depends on the number of drivers operating and their duty cycle. What I don't know is how they work out the power dissipated in the package. I know that P=VI , I know I, but don't know what value to use for V. I imagine it must be the voltage across the driving transistor, but I don't know where to find that.

Thanks in advance, Manuel