Design analysis of a gain-stabilized transistor amplifier at elevated temperatures using passive elements

The decrease of the emitter-base and collector-base junction voltages of a transistor with temperature and the effect of the external circuit resistances on these voltages are studied theoretically and experimentally. The influence of the shifting of the operating point with temperature on the gain is discussed. A new design approach based on V/SUB EB/ and V/SUB CB/ as the stability parameters is given using only passive components. It is found that this approach definitely leads to better gain stability with temperature than other design techniques using NTC elements. Although work in the early stages was concentrated on germanium transistors (-15 to +115/spl deg/C), already some encouraging results have also been attained in the study of silicon transistors.