ULN2803A: Interfacing ULN2803A with TIVA TM4C1294 - Pull up at input of ULN2803A

HARANATH VASAM1

Part Number: ULN2803A

In one of our new design we are using ULN2803A for driving Relay. Circuit is as given in attachment.

Please confirm whether PULL DOWN is required an Pin1 of ULN2803. And also confirm whether schematic is correct.

Thanks in advance.

0 Shreyas Dmello over 5 years ago

Hi Haranath,

I do not think the resistor R75 is needed as COM can be directly pulled to 5V.

There is no internal pull down or pull up for the IN pins so depending on your GPIO behavior, a pull down or pull up is necessary.

0 HARANATH VASAM1 over 5 years ago in reply to Shreyas Dmello

Thanks alot

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