Depending on which way you look, Intersil is connected to big names. When I first heard of Intersil, its data book also had RCA and GE on the cover. RCA (originally Radio Corporation of America) formed RCA Semiconductor in 1950 and was an early player in the transistor industry. In parallel, General Electric moved into the semiconductor business in 1954 with the formation of GE Solid State. In 1980, GE Solid State acquired Intersil. And in 1988, Harris acquired GE Solid State, which included RCA Solid State.  Jack Welch was president of GE and felt that the semiconductor business was too competitive for GE to dominate so he sold it to Harris. At Harris, the Intersil name was retired.
But wait, let’s back up even further and find out where Harris came from. In 1895, Harris Automatic Press Co. was formed to make printing presses. In the 1950s, that company, renamed Harris Corp., expanded into electronics. And in 1967, it acquired Radiation Inc., a manufacturer of space and military electronics located in Florida.  Fast-forward a few decades to when Harris owns the remnants of the old Intersil product line; Harris spun off the division and the new company was renamed Intersil in 1999. In 1999, then-CEO Gregory Williams cites the meaning of the Intersil name, "The first half of the new name signals our intention of pursuing Internet-related opportunities, while… the second half of the name underscores our legacy in world-class silicon technology." 
Too fast? Yes, of course, because I skipped Intersil’s entire first existence! And the original Intersil couldn’t have been an Internet Silicon company.
Credit for founding the original Intersil goes to Swiss-born Jean Hoerni together with H. Gebhatdt, and S. Wauchope (the latter two from Union Carbide) with funding from the Swiss firm SSIH to develop low-power MOS technology for watches and calculators.  Hoerni was working at the California Institute of Technology in the early ’50s, when his shy brilliance was noticed by William Shockley. The story of Shockley Labs and the founding of Fairchild is well known. Using what he modestly called “college level” physics, Dr. Hoerni (doctorates in physics from Cambridge University and the University of Geneva) invented the planar process, which enabled Fairchild Semiconductor to produce the first integrated circuit. His inspiration came to him during his shower one morning in 1958, at a time when Fairchild was completely stalled in their research. But plagued by an itinerant’s need to seek new opportunities, Hoerni would leave Fairchild after only a few years, before the company achieved its success with semiconductors. He would go on to found many more companies, the most notable being Intersil. 
Because of the international background of the founders and the Swiss funding, Intersil originally meant “International Silicon”.  In 1969, Dave Fullagar came over from Fairchild, fresh off the success of the µA741 op amp. He eventually rose to be Vice President of R&D. Fullagar once said,
“…the Intersil years were the most creative. I developed the first IC logarithmic and antilogarithmic amps and the first monolithic FET-input op amp, the ICL 8007, which dominated the market until the bipolar FETs came along.
I also got to spend a month in Japan designing the first electronic-shutter IC for a single-lens-reflex camera for Canon. This circuit took the logarithm of three inputs—film speed, aperture, and light intensity—summed the result, stored it while the mirror went up, and then took the antilogarithm to generate the shutter speed. It used about 20 transistors in total and was probably my most elegant design. Nowadays, this is done with about half a million transistors in a microcontroller—how prosaic.”
In 1971, Jack Gifford was asked to leave Advanced Micro Devices by Jerry Sanders (that’s another story). Jack wanted to start his own analog company. Hoerni asked Gifford to take over the analog side of his company. In exchange, he would help Gifford raise money to start his own business.  Gifford agreed and subsequently built Intersil up to a $130 million company. The analog side of Intersil under Gifford and Fullagar was a pioneer in CMOS analog circuits. The one that immediately comes to mind for me is the classic charge pump, ISL7660.
When GE acquired Intersil, they tried to keep the Silicon Valley spirit and entrepreneurship. By 1982, GE’s new president Jack Welch appeared to be reversing his earlier assurances to let Intersil keep its own stock-option plan. Several conversations occurred between Gifford and Welch until it finally came to a head after a few drinks at a company party. Jack Gifford, in his rapid-fire way, tells the story of how Jack Welch confronted him at the party:
“No sooner does the greetings stop and he says, ‘God damn it. Why the fuck do you guys have to have those stock options? There, you know, jeez.’ And he goes on and on and on in front of fifteen, fifteen. In front of twenty, twenty-five guys, you know. And just, I mean we'd talked about this, five different times, you know. And all of a sudden he's now, you know, coming like it's my fault, like I'm the problem, right? And he's, say he's had a couple of drinks, and finally he starts, ‘Well, what do you think?’ And I said, and I was going to react and I just, I says, I was so mad and I just said, ‘Fuck you.’ And I just turned around and walked out.” 
So Jack Gifford was fired from Intersil. Jack went back to farming for a a bit, then started to hear from his former colleages about how bad it was working for GE. So, in April of 1983, he founded Maxim Integrated Products with Fred Beck, Dave Bingham, Steve Combs, Lee Evans, Dave Fullagar, Roger Fuller, Rich Hood, and Dick Wilenken. GE and Intersil immediately filed suit, alleging infringement of trade secrets. The companies eventually settled, when Maxim agreed to let GE/Intersil pick 10 of Maxim's chips during the ensuing five years to manufacture and market on a royalty-free basis. In return, GE granted Maxim rights to certain product know-how, trade secrets and patent rights.  I’m told one of the alledged thefts involved the charge pump that went into the MAX232 and part of the final agreement was that Maxim would no longer recruit Intersil employees to join them.
So the original Intersil suffered under the huge corporate structure of GE. Now we can join the story that I started with Harris taking the Intersil group, dropping the name and eventually spinning it out again as a new company.
In 2002, the new Intersil acquired Elantec and Elantec's chief executive Rich Beyer became president and CEO of Intersil. After several more key acquisitions and a couple divestitures, we have the Intersil of today. Crazy as they were, the footsteps led us back to analog circuits.
Fun Fact: Jean Hoerni’s life did not revolve solely around research. A fanatically dedicated mountain climber, he scaled most of the world’s highest peaks, made a partial ascent of Mount Everest, and spent countless weekends in the Sierras. He was extremely strong, hiking at high altitudes with little food and never sleeping in a tent, and he was resourceful as well. To extend the life of an old sleeping bag, he stuffed it with newspapers. On waking up one morning above 12,000 feet, he said he planned to write a letter of appreciation to the editor of The Wall Street Journal saying that it was by far the warmest newspaper. On a trek in his later years, he became devoted to the Karakoram Mountains in northern Pakistan. Together with Greg Mortenson of Bozeman, Montana, (and author of “Three Cups of Tea”) Hoerni donated $12,000 to build the region’s first school and created a foundation called the Central Asia Institute with a $1 million endowment.
 “Intersil: Analog contender or pretender?” Mark LaPedus, EETimes.com
 “Jean Hoerni, 1924 – 1997” by Deborah Claymon, Red Herring, Feb. 1, 1997
 “Making Silicon Valley: Innovation and the Growth of High Tech, 1930-1970” by Christophe Lécuyer, 2006
 “Jack Gifford: Baseball’s Loss Was The World’s Gain”, Doris Kilbane, Electronic Design, Dec. 7, 2009
 Interview with Jack Gifford, July 17, 2002, Sunnyvale, California (http://silicongenesis.stanford.edu/transcripts/gifford.htm)
 InsideChips: Maxim Integrated Products, May 01, 2002, Steve Szirom, senior analyst
Jean Hoerni photo credit: Wayne Miller
Jack Gifford photo credit: EDN magazine