MOSFET or similar devices that hold their state when unpowered.
MOSFET or similar devices that hold their state when unpowered.
(OP)
Hi,
I am trying to identify a solid state device that will retain it's state when not powered. For example, I know that flash memory stores it's state by means of a floating gate that is capacitively charged and isolated from the drain/source. Unfortunately, I need a single discrete solid state device that will do this while passing a fair amount of current (>1 amp). I have considered a solid state relay, but I can not find a design that can retain it's state like a mechanical latching relay when it looses power.
Does anyone possibly know of a single discrete device that has such a capability, or a small circuit that could somehow manage to do this? I simply cannot find a solution using solid state devices.
Thanks
I am trying to identify a solid state device that will retain it's state when not powered. For example, I know that flash memory stores it's state by means of a floating gate that is capacitively charged and isolated from the drain/source. Unfortunately, I need a single discrete solid state device that will do this while passing a fair amount of current (>1 amp). I have considered a solid state relay, but I can not find a design that can retain it's state like a mechanical latching relay when it looses power.
Does anyone possibly know of a single discrete device that has such a capability, or a small circuit that could somehow manage to do this? I simply cannot find a solution using solid state devices.
Thanks
RE: MOSFET or similar devices that hold their state when unpowered.
Commercial devices based on that principle were available 50 years ago.
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Ohm's law
Not just a good idea;
It's the LAW!
RE: MOSFET or similar devices that hold their state when unpowered.
If the state is expected to continue while NOT being commanded then an SCR will do that. After being triggered ON it will continue to stay ON until current flow drops to the cutoff level which is quite low. If it's not triggered ON then it will 'remember' to stay OFF.
Keith Cress
kcress - http://www.flaminsystems.com
RE: MOSFET or similar devices that hold their state when unpowered.
RE: MOSFET or similar devices that hold their state when unpowered.
Another approach may be a very low power pilot circuit with a battery that will power it for years. The battery could also be recharged each time that power is available.
--------------------
Ohm's law
Not just a good idea;
It's the LAW!
RE: MOSFET or similar devices that hold their state when unpowered.
(Off topic - my favorite data storage was the acoustic wire torsion spiral. Puslses go in, the twists traveling at the speed of torsion, to the output where they would either be amplified and re-torqued or replaced.)
RE: MOSFET or similar devices that hold their state when unpowered.
http://www.righto.com/2019/01/inside-apollo-guidan...
64 bits of core memory in the 1960's took about the same space as 64 gigabytes of flash memory today (which uses quantum tunneling BTW).
jrodh,
I don't know much about what I'm talking about but I want to try a guess:
Do JK flip-flops return to their default state when power is removed&applied, or remain in their current state?
RE: MOSFET or similar devices that hold their state when unpowered.
In coin the flipping analogy, that would be; Heads, Tails and In Your Pocket.
When you pull the coin out of your pocket you don't know if it is heads or tails.
The gates that we were working with, memory gates, flip flops, sealed ands, and almost anything else that changed state, were in an unknown state when they were powered up. That was the "In Your Pocket" state. When a circuit was powered up, the first action was to send a reset signal to set the indeterminate gates to a known level.
That was before integrated circuits. Our gates were built with discrete components. More modern IC gates may have an internal reset function.
--------------------
Ohm's law
Not just a good idea;
It's the LAW!
RE: MOSFET or similar devices that hold their state when unpowered.
This also illustrates the set/reset needed on start-up.
--------------------
Ohm's law
Not just a good idea;
It's the LAW!
RE: MOSFET or similar devices that hold their state when unpowered.
--------------------
Ohm's law
Not just a good idea;
It's the LAW!
RE: MOSFET or similar devices that hold their state when unpowered.
I recall there was a recent kit to make your own core memory: https://www.tindie.com/products/kilpelaj/core-memo...
Still, not going to redirect amps of current.
RE: MOSFET or similar devices that hold their state when unpowered.
Apollo Guidance Computer Part 1: Restoring the computer that put man on the Moon
www.youtube.com/watch?v=2KSahAoOLdU
RE: MOSFET or similar devices that hold their state when unpowered.
RE: MOSFET or similar devices that hold their state when unpowered.
Use the EPLD for state storage and its output drives the power MOSFET; that combination would be TINY compared to pretty much any alternative. The fact that the EPLD stores several orders of magnitude more states is irrelevant; the space-claim would be about the same for a single state storage.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
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RE: MOSFET or similar devices that hold their state when unpowered.
Keith Cress
kcress - http://www.flaminsystems.com
RE: MOSFET or similar devices that hold their state when unpowered.
I think it needs its own power supply to produce an output so if the charge bled from the MOSFET gate it would not replenish it otherwise.
RE: MOSFET or similar devices that hold their state when unpowered.
--------------------
Ohm's law
Not just a good idea;
It's the LAW!
RE: MOSFET or similar devices that hold their state when unpowered.
Also in the running - Electronically Erasable Programmable Logic Device.
RE: MOSFET or similar devices that hold their state when unpowered.
EPLDs are not volatile, i.e., they retain state with zero power and typically, the manufacturers claim 10-yr retention.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm
RE: MOSFET or similar devices that hold their state when unpowered.
Keith Cress
kcress - http://www.flaminsystems.com
RE: MOSFET or similar devices that hold their state when unpowered.
https://www.mouser.com/Semiconductors/Programmable...
The original request is ambiguous. Latching relays retain their state even if the remainder of the control system is disabled/unpowered. An (E)EPLD won't drive a mosfet gate if the (E)EPLD is not powered. Not sure how long the static charge will remain on a mosfet to push it to saturation though I recall that allowing them to float is just good fun (not).
RE: MOSFET or similar devices that hold their state when unpowered.
Dan - Owner
http://www.Hi-TecDesigns.com
RE: MOSFET or similar devices that hold their state when unpowered.
I will investigate EPLD, reed switches, and SCR solutions. Core memory (while interesting) will not work.
Thanks!
RE: MOSFET or similar devices that hold their state when unpowered.
Here's the manual, it's a hoot.
https://www.makenoisemusic.com/content/manuals/ana...
RE: MOSFET or similar devices that hold their state when unpowered.
I already looked deep into this, theres nothing that will stay on when not powered.
Maybe enhancement mode mosfets though....sorry, i mean the very opposite of that...the fet that needs an active signal to turn it off...i forget the name
RE: MOSFET or similar devices that hold their state when unpowered.