[Libre-silicon-devel] "555" Repository + Schematic

Hagen SANKOWSKI hsank at posteo.de
Thu May 2 13:49:30 CEST 2019

Hello List!

I just add two more versions of the 555 schematic to the
github.com/libresilicon/CMOS-555 repository.

One is based on reversed-engineers work, published on righto.com; I took
the same number scheme for the circuits.

Another is from the already mentioned Book "Designing Analog Chips" from
Hans Camenzind, the original author of the 555. On page 148 he shows a
schematic for a 5V CMOS version. Well, this schematic is literally
similar to the Wikimedia Version. I called this the "Book Version" and
took also Hans number scheme (and dimensions!).

So, here we got an issue. The Version showed by Hans is for 5 Volt he
wrote. And, this version uses a feature size of 0.5 Microns on some
MOSFETs which is smaller than our 1 micron technology.
I think, we have to scale-up the dimensions for two reasons.

1. We do not get the right values from PearlRiver to calculate beta
right; 1 micron for L and 1.5 for W is the minimum we can measure on

2. The version is aimed for 5 Volt. If we like to run with higher supply
voltage for reasons, we have to enforce the gate length.

@Tatzelbrumm, @Ference, what do you think about that??

Hagen Sankowski

P.S.: The
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 555_Book-Version.png
Type: image/png
Size: 59289 bytes
Desc: not available
URL: <http://list.libresilicon.com/pipermail/libre-silicon-devel/attachments/20190502/e03e6557/attachment.png>

More information about the Libre-silicon-devel mailing list