CMOS or TTL version of 555 timer?

boogietone · Post by **boogietone** » 02 May 2011, 19:03

I understand that the CMOS version of the 555 timer is lower current and thus pops less. Is there ever a need to use the bipolar version? I am buying a batch and would get just one type if there is a "preference" or both if there is value in having both on hand.

Hides-His-Eyes · Post by **Hides-His-Eyes** » 02 May 2011, 19:10

For audio, always the CMOS. If you can't avoid it altogether.

For non-audio, I think it's more to do with how many 'gates' you can drive with the output. If the answer is "one or two", I don't think it matter.

boogietone · Post by **boogietone** » 02 May 2011, 19:44

Thanks for the reply. I'll stick to the CMOS.

Is there something else that can be used to replace a 555 altogether?

Hides-His-Eyes · Post by **Hides-His-Eyes** » 02 May 2011, 20:28

There's nothing a 555 can do that another circuit can't do. There is however not much that can do EVERYTHING a 555 can do...

boogietone · Post by **boogietone** » 03 May 2011, 03:36

Thanks.