Abstract
A contribution to the understanding of total dose degradation using both AC small signal analysis and DC analysis in linear bipolar circuits is proposed. The reasoning is illustrated step by step on the basis of experimental results obtained on the LM 139. It is shown that the input stage is mostly responsible for the degradation up to 20 krad. Above 20 krad, the total degradation is due to a combination of the input and the output stage degradation. The amplifier stage does not play a significant role in the circuit deeradation