COTS ADC & DAC selection and qualification for the GLAST mission

Low-voltage low-power ADCs were radiation tested for selection to use on calorimeter instrument of the gamma-ray large area space telescope (GLAST). The GLAST instrument detects the most energetic photons, gamma rays, and pinpoint their source direction and energy. The GLAST instrument has a low-Earth orbit with an expected lifetime total-dose radiation exposure less than 5 krad. Both the Maxim MAX145 and MAX1241 CMOS ADCs were tested to be single event latchup (SEL) immune to an LET of 60 Mev/mg/cm/sup 2/. The MAX145 is used on the GLAST instrument. A companion device MAX5121 was selected as the flight DAC that also did not show SEL to 60 MeV/mg/cm/sup 2/. In presenting the data from all the ADCs and DACs tested, and explaining our test and qualification process, we hope to aide other designers with this difficult process.