Early voltage determination

[walid1]

When someone want to make a design using a BJT as amplifier, he needs to determine the early voltage of that BJT. How one determine it, or are there any standard approximations of it?
Thanks.

 

[audioguru2]

The Early voltage is the rise in a BJT's collector current with increasing supply voltage when the base current is constant. It was discovered by a guy with the name of Early and is shown on a transistor's datasheet. The Early voltage and a transistor's distortion can be cancelled with negative feedback from an emitter resistor or biasing the base from the collector.