There is no need for a zener,
there is already an internal diode that is used as a back EMF protective diode for inductive loads,
you just have to connect the common pin to the positive supply.
There is no need for a zener,
there is already an internal diode that is used as a back EMF protective diode for inductive loads,
you just have to connect the common pin to the positive supply.
I remember several applications where a zener diode is appropriate. E. g. if the ULN is switching loads with multiple and sequenced power supply. Or you want to allow a higher back e.m.f. for faster release of contactors or solenoid valves.