Transistor Datasheet

[Havass]

Hello,

I want to design a clapp oscillator with the transistor BFP650.  But I dont know which hfe is the correct one. Without it, I can`t calculate Ic and Ib

Ty 

[Kim Christensen]

Design your circuit so it's not overly sensitive to variations in beta.

[magic]

Is this the Infineon datasheet?

In fig. 3 the μA number on the right traditionally indicates base current corresponding to given line. This implies β in excess of 100.
Fig. 5 and 6 can be combined to produce β estimate at 2V Vce - the result is again in excess of 100.

It looks like fig. 4 may be the wrong one.

[golden_labels]

Could it be, that Fig. 4 has “% maximum” on the vertical scale, not A/A?

[Vovk_Z]

Anyways, I guess we have to take the minimum one for calculations.

[magic]

Could it be, that Fig. 4 has “% maximum” on the vertical scale, not A/A?

Sometimes hFE is plotted as percentage of the value specified in "electrical characteristics" table. Then it would be 100% at 5mA for this part.
I guess percentage of the maximum is also a possibility, though I don't think I have ever seen it yet.

[Kim Christensen]

Build a Clapp circuit properly biased like this one and all you'll have to worry about is the minimum beta spec.