What happens if I atack a BJT by decollector ?

[lean]

bjt icb0

What happen if I atack a bjt by de collector,
and the base is grounded.

It is very important to me

Thanks

 

[Borber]

Re: bjt

Bjt consists of two diodes connected antiseries. At NPN type anodes are connected together and at PNP cathodes are connected together. This connection is base connection. Other two pins are emitter and collector. You can "attack" these diodes with voltage or current. Behaviour of diode is known to you I believe.

 

[krashkealoha]

Re: bjt

I'm not familiar with the term "attack," but if you sweep the collector voltage positively with respect to the base, which is at ground and the emitter open, you will be measuring very small currents (pA range but this dependent on junction area). As the collector voltage is increased with respect to the base you will hit a critical electric field within the c-b junction which will result in avalanche breakdown. This will result in a sharp and large increase in current. This is a typical way of measuring collector-base breakdown in BJTs. The voltage at which breakdown occurs is dependent on the background concentration of your collector region.

If you sweep a negative voltage on the collector with respect to the base, you will foward bias your collector-base junction and the behavior would be the same as a foward bias diode.

 

[cetc1525]

bjt

does it use to test the leakage of current ?

 

[Borber]

Re: bjt

As krashkealoha explained for NPN BJT, as far as emitter is left opened (not connected) you can measure all parameters of diode B-C.
Leakage current reversly polarized diode B-C is called Icb0 and can be measured. Quick test of Icb0 can be made with the ohmmeter using 3V battery (measured resistance should be above 1Mohm.)

 

[krashkealoha]

Re: bjt

does it use to test the leakage of current ?

Yes you can use this method to test the collector-base leakage current. I would recommend using a semiconductor parameter analyzer (4145/4155 models). You can sweep the voltage across the collector-base junction and plot the leakage current. It will allow you to plot the current in log scale which is a real big help when analyzing reverse-leakage currents.