Total dose induced increase in input offset voltage in JFET input operational amplifiers

Four different types of commercial JFET input operational amplifiers were irradiated with ionizing radiation under a variety of test conditions. All experienced significant increases in input offset voltage (V/sub os/) for the worst-case irradiation bias. Microprobe measurement of the electrical characteristics of the de-coupled input JFETs on both non-irradiated and irradiated circuits demonstrates that the increase in V/sub os/ is a result of the mismatch of the pinchoff voltage of the degraded JFETs.