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

Christoph Maier christoph.maier at ieee.org
Thu May 2 14:02:33 CEST 2019

At the moment, I'm happy that I can open the schematic with standard
geda from my old ubuntu distribution.
I'm wondering if the 7555 uses actual resistors instead of mosfets,
and if the 7555 uses resistors, what their actual values are.


On Thu, May 2, 2019 at 1:55 PM Hagen SANKOWSKI <hsank at posteo.de> wrote:
> 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
> PearlRiver.
> 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??
> Regards,
> Hagen Sankowski
> P.S.: The
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