Timeline for Silicon Controlled Switches: applications&suppliers
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 23, 2012 at 5:26 | comment | added | Russell McMahon♦ | IF Germanium transistors had been developed as a niche line by now we'd probably have a few that would have got rid of most of the inherent shortcomings. I'd dearly love some well developed small signal germanium transistors for occasional use in ultra low voltage startup circuitry (Vbe ~= 0.2V) but you now pretty much cannot even find very old ones for sale. | |
| Jan 23, 2012 at 5:25 | comment | added | Russell McMahon♦ | In a semiconductor technology 'arms race', generally what works best at least all-up cost per performance metric that best reflects customer demand wins in this sort of market. The bubble memories, CCD memories, core memories Josephon junctions, Esaki diodes and their ilk are still around and may have niche applications but are in little use. In the power area SCS joins Germanium transistors, copper oxide and selenium rectifiers and to a large but not complete extent power bipolar transistors. Some may even make comebacks (eg Josephon junction) but most won't. | |
| Jan 23, 2012 at 5:19 | comment | added | Russell McMahon♦ | @Feynman - very few people arrange FETs's "back to back with opposed polarity" as I have described. It is done, but in most cases being able to arrange individual MOSFETs in topologies that suit the current need is laible to be less srestricting than having to use a necessarily more expensive part. A MOSFET lends itself to being "grown" in layers. Two MOSFETs in series with opposing polarities could be implemented but takes more steps and almost certainly needs many compromises. | |
| Jan 23, 2012 at 3:20 | comment | added | Alex Eftimiades | Ok, but that still begs the question of why dual bipolars caught on and SCSs did not. Perhaps I should start a new thread, but are there any FET equivalents to SCSs? I know I could just use transistors, but I was just curious as to whether it might be something to look into since I almost always seem to wind up arranging my transistors in this fashion anyway. | |
| Jan 23, 2012 at 1:46 | comment | added | Russell McMahon♦ | @Feynman - SCS and MOSFET use different base technologies. MOSFET is a resistive channel, SCS isn't. SCS is bestter compared to dual bipolars. | |
| Jan 23, 2012 at 1:05 | vote | accept | Alex Eftimiades | ||
| Jan 23, 2012 at 1:04 | comment | added | Alex Eftimiades | Ok, I guess I will just use mosfets with an H-bridge, but it sure seems odd that SCSs died out of use. To me, SCS is to a pair of mosfets as CMOS is to NMOS (or PMOS if you use two p-channel mosfets.) So naturally, I am still confused as to why the advantages gained from balancing p and n channels were outweighed by the costs of tacking on one extra lead. | |
| Jan 23, 2012 at 0:32 | history | answered | Russell McMahon♦ | CC BY-SA 3.0 |