Editing 4000-series integrated circuits (section)

==History==
[[File:4029 CMOS.JPG|thumb|right|A very early CD4029A counter IC, in 16-pin ceramic dual in-line package ([[Dual in-line package|DIP]]-16), manufactured by [[RCA]]]]
[[File:CD4011BE TI détail.jpg|thumb|right|Colorized IC die and schematics of CD4011BE [[NAND gate]]]]
The 4000 series was introduced as the ''CD4000 COS/MOS'' series in 1968 by [[RCA]]<ref name="CH_CMOS"/> as a lower power and more versatile alternative to the [[7400 series]] of [[transistor-transistor logic]] (TTL) chips. The logic functions were implemented with the newly introduced [[CMOS|Complementary Metal–Oxide–Semiconductor (CMOS)]] technology. While initially marketed with "COS/MOS" labeling by RCA (which stood for Complementary Symmetry Metal-Oxide Semiconductor), the shorter ''CMOS'' terminology emerged as the industry preference to refer to the technology.<ref>{{Cite web |url=http://www.edn.com/article/CA6343247.html |title=Wright, Maury. ''Milestones That Mattered: CMOS pioneer developed a precursor to the processor'' EDN, 6/22/2006 |access-date=2006-07-01 |archive-url=https://web.archive.org/web/20070927173331/http://www.edn.com/article/CA6343247.html |archive-date=2007-09-27 |url-status=dead }}</ref> The first chips in the series were designed by a group led by [[Albert Medwin]].<ref name="Baker2011">{{cite book|author=R. Jacob Baker|title=CMOS: Circuit Design, Layout, and Simulation|year=2010|publisher=John Wiley & Sons|isbn=978-1-118-03823-9|page=7|edition=3rd}}</ref>

Wide adoption was initially hindered by the comparatively lower speeds of the designs compared to TTL based designs. Speed limitations were eventually overcome with newer fabrication methods (such as [[Self-aligned_gate|self aligned gates]] of polysilicon instead of metal). These CMOS variants performed on par with contemporary TTL. The series was extended in the late 1970s and 1980s with new models that were given 45xx and 45xxx designations, but are usually still regarded by engineers as part of the 4000 series. In the 1990s, some manufacturers (e.g. [[Texas Instruments]]) ported the 4000 series to newer [[HCMOS]] based designs to provide greater speeds.