Re: tunnel diodes retrace lines in curve tracer

Jim Ford

Hmmm... Might there be a way to combine the TD and the transistor?
Something compatible with the ginormous silicon CMOS infrastructure already in place? I no longer work for a semiconductor shop, so I don't have access to the brainpower there anymore, but people on this group must. Put your thinking caps on....

Jim Ford

------ Original Message ------
From: "Tom Lee" <>
Sent: 2/18/2021 2:14:43 PM
Subject: Re: [TekScopes] tunnel diodes retrace lines in curve tracer

Tunnel diodes excited a lot of interest for about a decade after their commercial introduction. In fact, TDs and the first IC from Fairchild (a four-transistor flip-flop) competed for attention at what is now the ISSCC conference, in 1961. The press largely ignored the IC. Articles from that time were obsessed with the tunnel diode instead. The future was going to be powered by TDs. Supercomputers, satellites, Dick Tracy wristwatch TVs...all were Coming Real Soon (tm), thanks to TDs. Then reality hit: Yes, they were much faster than contemporary transistors, but they were two-terminal devices. Making a chain of amplifiers was difficult because a change in load /here/, rippled all the way back to the input /there/. The same problem afflicted networks of logic gates. So scaling up to large systems seemed unlikely. Various desperate, complicated arrangements were devised in an effort to fix that and other practical problems, but the added complexity nullified the putative advantages of the TD. After a few turns of the Moore's law crank, it was clear that the IC was the future, and the TD gradually became the answer only to trivia questions.


-- Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070

On 2/18/2021 13:54, saipan59 (Pete) wrote:
My understanding is that by the 1970's or so, TD's were obsolete because most of the practical circuits that used them could be done cheaper with modern transistors and IC's.
TD's could do certain things with a bare minimum parts count, but that wasn't important enough, with the parts count (inside of IC's) exploding in other areas.
Also note that many of the interesting apps for TD's involve inductors, but inductors are not cheap.

I could be wrong...


Join to automatically receive all group messages.