This Repository is for LibreSilicons's completely Open Source Timer IC "NE555" clone.
The Original "triple-5" chip is legendary. Once developed by the Swiss electronics engineer Hans R. Camenzind, working for Signetics, gets cloned by many different companies and is nowadays still in production and still a bestseller. While the first designs were build with Bipolar Junction Transistors (BJT), also a couple of clones are made in Complementary metal-oxide-semiconductor (CMOS) technologies.
This Chip here uses the LibreSilicon 1 µm CMOS-Technlogogy and contains two separted "555" on the same die - being acurate the Chip becomes functionaly similiar to the "7556".
The Schematic for the CMOS-555 is done with the Schematic Entry program from Lepton-EDA - a GNU EDA tool clone with more active development than the original and the same License. On Debian-based Linux systems, you get lepton-schematic as part of the whole PCB tool suite Lepton-EDA by
apt-get install lepton-eda
as part of the whole PCB tool suite Lepton-EDA.
A very usefull kind-of "Simulation Program with Integrated Circuit Emphasis" (SPICE), originaly from Berkley University is ngspice. Of course, this Open Source, general-purpose, analog electronic circuit simulator comes with Linux systems, e.g. on Debian-based systems with
apt-get install ngspice
Please make yourself familiar with Simulations using Spice.
Another software tool, which should be installed before usage, is Magic. Magic is Open Source, but not part of all Linux distributions (lacks on OpenSuse, Arch Linux etc). On Debian-based systems
apt-get install magic
works.
Best Documentation about Analog Design and the "555" you'll find at Camenzind's Book Site. The Book is a great Textbook for analog Chip design; read it, study it, it is worth the time. For offline reading, you'll find the Download Link on the Book Site.
Of course, the "555" also has a Wikipedia Page.
lepton-schematic Sources/geda/555_Wikimedia-Version.sch
magic -T scmos.tech Layout/magic/CMOS-555.mag
magic -T scmos.tech Layout/magic/CMOS-556.mag