Simple precision bias circuit for medium-power amplifiers

Describes a new bias current regulation circuit for single-stage bipolar and FET amplifiers which achieves high precision and simplicity through a combination of feedback error amplifier with bandgap reference. The internally generated reference voltage can be preset between 100-200 mV. The approach is ideal for applications where the overhead voltage must be minimized to reduce power dissipation, and typically offers <0.5% regulation and ⩽40 ppm/°C temperature coefficient. The authors present three common applications which demonstrate the unique advantages of the new topology