Transistor, Data Sheet, PN2222, Two diff. pin configs on spec. 2

[joecad]

Does anyone know the correct pin config. for the transistor, PN2222, My specsheet has two conflicting configs.
Also is there a way to test cbe on this part with a simple volt meter.

Thanks,

joecad

 

[Lewish]

There are in fact 2 different pin-out variations of this part. If you want consistency, then use a 2N2222.

 

[IRstuff]

A voltmeter will at least tell you which pin is the base, since both b-e and b-c junctions are the same type. If you have a simple transistor tester, you can find out which way the transistor is operating by the asymmetry in forward and reverse beta.

The other thing you can look at with a voltmeter is the leakage current and breakdown voltage across the two junctions. Standard vertical transistors use a degenerately doped emitter, which usually means that the emitter base junction will have higher leakage as well as a lower reverse breakdown voltage. The collector-base junction is usually lightly doped on both sides, thereby resulting in lower leakage currents as well as higher breakdown voltages. TTFN

 

[47gandalf]

one of these days i'm going to find a tektronix curve tracer at a garage sale and snap it up! they're old and ugly, but you can do a million things with them, including this.

actually i think Sencore (among others) makes a low cost curve tracer that would help if you're trying to check reverse breakdown voltage and leakage current.

in the short term, look at the manufacturer's data sheet and trust it; once you've confirmed where the base pin is.