Inverse mode BJT

[John Bachman]

A friend of mine recently discovered that bipolar transistors work in
inverse mode. He told me of his discovery and was dismayed to know
that I had not only heard of such a thing but had used it in designs
eons ago.

However, I do not recall the reasons that I did so (it was 25 years
ago) and what the characteristics of inverse BJTs are.

Can anyone lead me to a link that explains it all, for me and and my
friend?

TIA

John

 

[[email protected]]

A friend of mine recently discovered that bipolar transistors work in
inverse mode.  He told me of his discovery and was dismayed to know
that I had not only heard of such a thing but had used it in designs
eons ago.

However, I do not recall the reasons that I did so (it was 25 years
ago) and what the characteristics of inverse BJTs are.

Can anyone lead me to a link that explains it all, for me and and my
friend?

No, but when I used inverse BJT's back then it was to take advantage
of the really low saturation voltage you get when you use an inverted
BJT as a saturated switch.

 

[Fred Bartoli]

Robert Baer a écrit :

Vacuum tubes work in inverse modes also..how does a "plate follower"
grab you?

Not really, just grid and plate swapped.

 

[Tim Williams]

Vacuum tubes work in inverse modes also..how does a "plate follower"
grab you?

http://members.aol.com/sbench102/inverted.html et al.

Meh, negative screen current is more interesting. Don't see that too
often.

Tim

 

[[email protected]]

http://analog-innovations.com/SED/InvertedTransistors(Hunter).pdf

You'll probably have to paste the URL into your browser... Agent
doesn't seem to like the parentheses and may not pass that information
on to your browser.

I think I remember reading somewhere that a bipolar run inverted
will
slowly get a lower and lower gain, but that the gain can be brought
back up by heating it for a few seconds.

-Lasse

 

[MooseFET]

http://members.aol.com/sbench102/inverted.htmlet al.

Meh, negative screen current is more interesting. Don't see that too
often.

If you put enough forward current on the control grid, you can operate
a tube in a mode that makes a very high gain device. It is a grid
vapor amplifier for a little while. The plate will carry many amps.


There was a tube that had the suppressor grid brought out on its own.
It was intended for allowing it to be at AC ground when the cathode
wasn't. On one of those you could get gain from the secondary
electrons if you pulled it positive.