Help understanding transistor datasheet

Other Hardware General Electronics
1

Ive been taking apart some old stuff. One was an old wall wart, another was a broken dvd player and the third device was a toy, I think that someone gave me. They gave it to me in pieces just like the dvd player so Im not sure what that 3rd device was. The dvd player was a bit more recognizable.

So Ive found 3 things that caught my attention:

A. Two BR8550's which turn out to be amplifiers? According to the data sheet: "2W output amplifier of portable radios". Its a transistor and has the following parameters:

C-B Voltage = -40
C-E Voltage = -25
E-B Voltage = -6
C Current = -1.5A

So Im wondering how I can interpret this data to be able to use it for something

B. One TL431 which is a 3 terminal shunt regulator. I have no idea what to use this for?

C. K2996 - Nchannel Power mofset - dont think i can use it for anything

D. LT 821 - Couldnt find anything

E. YC27.00 crystal oscillator - dont think i can use it for anything

F. GF8050 viper22A which seems to be a switch - dont think i can use it for anything

G. en25f80 which seems to be a memory module - dont think i can use it for anything

I guess what interests me the most is the transistor up top.

Can someone help me interpret the data?

Thanks

2

Please provide a link to the transistor data. It doesn't look right.

3

I guess what interests me the most is the transistor up top.

This is an old PNP transistor.
On application is a high side switch.
http://www.electronics-tutorials.ws/transistor/tran_3.html

4

Vceo is the max voltage between Collector and Emitter with the base Open circuit (negative for PNP)
Vcbo is the max voltage between Collector and Base with the emitter Open circuit (negative for PNP)

Vceo is the basic absolute maximum voltage you should expose the transistor to, Vcbo is only
useful if using the transistor as a diode (almost never done in practice!)

Veb is the reverse breakdown voltage of the base emitter junction, it is always about 5V (-5V PNP).
The base-emitter junction is heavily doped and acts as a (true) zener diode, basically.

Max collector current is self-explanatory. It is negative as the convention with currents is to call
sinked currents as positive and sourced currents as negative. Thus positive power supply currents
are positive since the device sinks them.

The convention with signs isn't always followed - some PNP datasheets have no negative signs, but
its more common than it was, and its invaluable with a datasheet for a dual NPN-PNP transistor
device as you can't accidentally confuse the two parts!