Total dose tests for the PROMICS-3 instrument

The sensitivity of some analog and digital integrated circuits (IC's) to ionizing radiation was tested in order to evaluate their potential usefulness especially in the PROMICS-3 instrument. The PROMICS-3 is a plasma instrument to be flown on the Russian Interball satellites. The radiation tolerance requirement of the auroral Interball satellite is about 45 krad/year inside a shielding of 4 mm Aluminium. The IC's tested were: AD571 A/D- converter, ADDAC80 D/A-converter, LF442A and PM108A operational amplifiers, MPREF0l voltage reference, STC SPXO 6 MHZ oscillator,4N55 optocoupler, MC5lC98 and CY7C164 16k*4 static CMOS RAM. Co-60 was used as the irradiation source. The test methods and results are described in the paper. The RAM-circuits failed between 10 and 20 krad. D/A- and A/D-converters degraded only slightly after 100 krad, but one of the A/D-converters failed functionally at 190 krad. The LF442A began to degrade in the test connection at 100 krad, and PM108A at 30 krad. The output voltage of the voltage reference MPREF01 increased about 20 mV after 100 krad. No change was observed in the output frequency of the STC SPXD oscillator even after 300 krad. The current tansfer ratio of the 4N55 decreased continuously to about 75 % of the initial value after 100 krad