Analysis of current-mirror MOSFETs for use in total-dose radiation environments

The suitability of current-mirror MOSFETs (CMFETs) for use in total-dose radiation environments was examined. These devices allow low-loss load-current sensing and have significant potential for use in power integrated circuits. Experiments demonstrated that the ratio of the load current to the sense current was virtually unaffected by ionizing radiation for many operating conditions. In all cases examined, changes in current ratio were largest when the sense resistance was largest, and smallest when the sense voltage was approximately equal to the load-section source voltage. A demonstration circuit was used to verify the feasibility of using feedback to extend the useful life of CMFETs in total-ionizing-dose environments