What is a T092 transistor?

I found a site that has a bunch of T092 transistors for cheap.

Is a T092 some generic transistor? I found this datasheet but I'm not sure if it's right:


I can't make a whole lot of sense from the data sheet. I'm looking to uses these transistors as a digital switch. How much voltage/current can I pass across the base -> emitter? 7v? How much current? Could I do 5v and .5a?

What's the difference between the Emitter-base breakdown voltage and the Base-emitter saturation voltage?

TO92 is the package style.

i.e. the shape?


.e. the shape?

Correct, it designates the size, shape and number of leads of the device. What a TO92 designation doesn't tell one is if it is even a transistor or not, it could be a number of different semiconductors. Just as if a IC is described as a DIP, that is just a packaging designation also.


TO92 is simply a definition of the shape of the transistor case.
The data sheet you have specified is for a transistor of TO92 shape

The base emitter breakdown voltage is the voltage that causes the junction to "breakdown" maybe irrevocably.

Generally transistors should be considered as current amplifiers, a small amount of base-emitter current being multiplied by the transistor gain to produce a much higher collector-emitter current.

When the transistor is conducting you might expect to get a base-emitter operating voltage of around 0.7 volts, but remember it is the current that does the work so you need to set a suitable base resistor to limit this current. Say you have a transistor of gain 50 and you want to switch collector load of around 100ma then you need a base current of at least 2 ma so a 5 volt signal might need a limitting resistor of around 2.2kohms. Generally in such a case I'd suggest a value of around 1000 ohms to ensure the transistor is fully turned on.


That's not a bad deal for the number of transistors, but you don't know whether you are buying an NPN or PNP type (until you get them home and can put a meter on them). Even so, after you figure that out, you still don't know the actual characteristics/specs, so you can only guess.

Personally, for the price, I would buy some (if I didn't already have a ton, that is) - then once I knew what they were (NPN or PNP) I would treat them like a 2N2222 (NPN) or a 2N2907 (PNP - complement to the 2N2222).

Most likely these transistors are one of the two; and I would almost hazard a guess that they -are- 2N2222s (a very, very, very common TO92 transistor for decades). For under $2.00 its worth the gamble.

For $1.50 I ordered them. I’ll probably end up using them as digital switch instead of as an amp.