Hi everyone,
I have a device where I am driving two relays (Digikey PN#PB110-ND) with a ULN2003A (Digikey PN#296-1368-5-ND) from a 16F688. I have tested this layout quite extensively from January of this year without using flyback diodes to supress the voltage when the field collapses. I have not seen any failures yet and it does appear that the ULN2003A protects itself. I read the data sheet and it says, "Each consists of seven npn Darlington pairs that feature high-voltage outputs with common-cathode clamp diodes for switching inductive loads." Forgive me for not really understanding this situation as I don't have an EE degree but I would like to know if I really NEED to add flyback diodes. I know it's common practice when using a simple NPN transistor but again, do I really NEED them with a ULN2003A.
Thanks in advance for the help.
Chris
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