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pcf

Jan 1, 1970
0
Hi I am a beginner in electronics stuffs (inparticular, transistor)

I would like to know whats the "threshold" of VCE when the NPN works
from stauration to linear region.

The Ic I am using is ~50mA at most. I believe the threshod of VCE is
~0.3V

Am I right?

pls reply to my email as well

Thanks !

PCF
 
R

Robert Baer

Jan 1, 1970
0
pcf said:
Hi I am a beginner in electronics stuffs (inparticular, transistor)

I would like to know whats the "threshold" of VCE when the NPN works
from stauration to linear region.

The Ic I am using is ~50mA at most. I believe the threshod of VCE is
~0.3V

Am I right?

pls reply to my email as well

Thanks !

PCF

A transistor is still active and fully operational at zero volts
collector to base, and partly active even with small forward biasing.
One needs toforward bias the collector-base region sufficently to then
"flip" the operation to inverted mode where the collector acts as an
emitter and vice-versa.
Such operation has been used to achieve lower than "normal" on voltage
drops, especially in signal choppers.
Most transistors have a very crummy beta in the inverted mode, and can
run from 1E-3 to a high of 0.10 .
However, there are some high forward beta transistors that also have
inverted betas that exceed one and may get as high as 50 (!!), made by
Zetex; the ZTX696B is an NPN with beta (min) of 500, and the ZTX718 is a
PNP with beta (min) of 300. As i remember, their reverse beta is rather
spetacular when compared with ordinary transistors.
 
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