To begin our “part finder fridays” were going to lean on our good buddy the 555.

• The most common timer chip is the 555, but it comes in a few flavors!
• 555′s are commidified, you’ll see them made by dozens of manufacturers.
• Pretty much any ’555 is pin compatible with different power ratings, voltage ratings, max frequency etc.
• NE555, SE555 LM555 is the ‘original’ TTL version but is power hungry, and needs 4.5V or higher to run! In general the CMOS versions are better
• The LMC555/TLC555 is the lighter-weight CMOS version, it can run as low as 1.5V, with much less power dissipation. These are your bread and butter!
• The TLC551CP is ultra low voltage, can run on 1V, making it perfect for single-alkaline-battery operation

We have links for purchase, and of course the EagleCad library reference. Its all in the wiki so if you have some other 555′s you like or other purchase links please add them in!

Looking for parts? Stop by the parts wiki!