SN74HCT240: Design Question

Alex Segler

Expert 4621 points

Part Number: SN74HCT240

Tool/software:

Hello team - can you help with the question below? Thank you

I was wondering whether the circuit shown below using SN74HCT240 is generally bad design practice on a single package?

Multiple inputs are being tied together
Multiple outputs are being tied together
One output loops back to multiple inputs

This circuit is being used as a differential 5V switch.

over 1 year ago

0 Owen Westfall over 1 year ago

TI__Genius 15501 points

Hi Alex,

Tying outputs together if they are connected to the same input is generally okay see [FAQ] Can I connect two outputs from a CMOS logic device together directly?.

It's very strange to see the loop, but there is nothing inherently wrong with this. I suggest simply using a higher drive strength device like the SN74ACT240, so you can save space by going to a smaller pin count device, and don't have to tie as many channels together.

Regards,

Owen

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SN74HCT240: Design Question