Good Day All.

I am trying to find a compatible to the 2N4033 but in a TO92 package.

And somewhere I can buy local, so in my case that will be Maplin or RS.

Thanks for your time.

Best Regards.

 

PNP, 80V, 1A, Hfe = 70@500ma

 

Try BC640 @ .27 lb.

 

You may very well run into a power dissipation problem.

The 2N4033's TO-39 package can handle up to 4 Watts (if properly heat-sinked), but the TO-92 package is limited to 625mW. It even has a minimum gain of 70 when Ic=500mA, and 25 when Ic=1A. That's going to be hard to find.

You might look at a ZTX753; Farnell should have them in stock.
Datasheet: http://www.diodes.com/datasheets/ZTX752.pdf

 

Thanks for your replys so far.

I am trying to control a 5volt device from a micro-controllor, but the device in question pulls more current then the micro-controllor can safey handle.

The sample design says to use a 1k resistor from the output pin of the micro-controllor, and then to the base of the 2N4033, 5volt supply on the emitter, and the load connected to the collector.

Looking into it in more detail, I only need a max current of 500ma output.

If this helps at all can you now advice a better suited item?

Thanks for your time.

Best Regards.

 

What? The transistors we named won't work?

 

hello, it seems to me that the ZTX753 will do just fine.

It can handle 2 amps continuous. Your request for 500ma is more than covered.

 

I'm concerned that the gain for the ZTX753 is not high enough.

Use a ZTX792A instead:
http://www.diodes.com/datasheets/ZTX792A.pdf
Distributors and stock are shown halfway down this page:
http://www.diodes.com/products/catalog/detail.php?item-id=647

Use a 270 Ohm resistor from the base to the uC's I/O pin. You want the Vce(sat) to be as low as possible without stressing your I/O pin. 270 Ohms will give you 15.9mA base current. This should give you a Vce of just over 0.1v (around 120mV according to the Vce(sat) plot on page 3 of the datasheet) which will give about 60mW power dissipation in the transistor, well within limits.