ABSTRACT
Most, if not all, electronic circuits require a reference, be it voltage, current, or time. A well-designed reference is expected to establish a stable point which is independent of the potential variations in the circuit’s operating conditions. A current reference, generally being used as the biasing stage, sets the “master” current from which the required biasing currents of other transistors are mirrored. In addition to establishing transistor’s operating point, the current value impacts transistor’s dynamic behavior through controlling its transconductance. Therefore, any “unwanted” variation in the current reference could potentially change both circuit’s “dc” and “ac” properties in an unpredicted way.
