Bipolar Junction Transistors - How does one read the datasheet?

[d.arbitman]

In particular, I am looking at a datasheet of a PNP BJT:
http://www.fairchildsemi.com/ds/2N/2N3906.pdf

I noticed that in the ON CHARACTERISTICS sub-heading, there were multiple h_{FE} values. I'm wondering how I could extract any meaningful information from that since the most common h_{FE} value is ~100. I also don't understand why the test V_{CE} value is only -1.0V; shouldn't there be a wider range of applicable voltage drops from collector to emitter. How would I interpret the information provided to me in that section?

 

[NascentOxygen]

There is a wide spread of h_FE for this device. Furthermore, h_FE also varies with collector current (there's a graph showing this). This tells you that whatever circuit you use, that circuit should be designed to be tolerant of a wide variation of h_FE. Either that or you must individually test a handful of devices and pick the one with the highest gain. (Not advisable, as repair and replacement may well see the circuit not function.)

I think you'll find that the variation of h_FE with V_CE is of the same order, or overshadowed by, the variation of h_FE with I_C. You can judge for yourself if you unearth a plot of I_C versus V_CE on another manufacturer's datasheet: the more horizontal the lines, the less the variation.