The world’s first integrated circuit may be older than you think!

Electrical Tester – 8 June 2018

For many of us, the history of the integrated circuit starts one hot July day in 1958 when Jack Kilby was sitting alone at his desk in Texas Instruments. Having been employed with the company for only a couple of months, he couldn’t take holiday like the rest of his co-workers so remained at work in the deserted factory halls. And as he had ample time to think, he figured out that all parts of a circuit, not just the transistors, could be made out of silicon – at a time when nobody was making capacitors or resistors out of semiconductor materials. By September 12, Kilby had built a working model, and on February 6, Texas Instruments filed a patent. The company’s  “solid circuit”, the size of a pencil point, was shown to the public for the first time in March of the next year.

Of course, depending on which version of history you choose to side with, you might prefer to believe that Westinghouse Electric of Youngwood, Pennsylvania was responsible for the first silicon IC, having produced one at roughly the same time as Texas Instruments.

But what if I told you that the first device with good claims to be an integrated circuit went into production as early as 1926? Even though the world’s first IC looked quite different from the ones we know today, the basic concept was developed by Dr Siegmund Loewe, founder of the Opta Electronics company in Berlin.

Loewe’s device, for which he was granted a patent in 1924, used vacuum tube technology and consisted of three triodes and a number of resistors and capacitors encapsulated in an overall glass envelope. The external connections were brought out to pins, and the device could be plugged into a socket in the same way as an ordinary vacuum tube. The design was slightly improved over the next couple of years and, by 1926 it was put into production with the designation 3NF.

The 3NF was used as the basis of the Loewe OE333 AM radio receiver and contained most of this receiver’s components. The only external devices were a tuning coil, a swinging aerial coupling coil, a tuning capacitor, a loudspeaker and the high tension and low tension (A and B) batteries which supplied the anode and the filament power.

The cost of this new technological wonder was 39.50 Marks and it must have been seen as offering good value for money, as it became the first ever radio receiver to sell in excess of one million units – a tremendous achievement for the inter-war period.

The discovery and successful production of the first IC are events that most engineers would firmly place in the 1950s but, as we have seen, there was a spectacularly prescient invention  thirty years earlier that paved the way for  modern electronics.