Latchup in CMOS analog-to-digital convertersHeavy-ion latchup is investigated for analog-to-digital converters. Differences in cross section for various ions shows that charge is collected at depths beyond 50 um, causing the cross section to be underestimated unless long-range ions are used. Current distributions and thermal imaging were used to identify latchup-sensitive regions. Latchup in one of the circuittypes was catastrophic, even when the power was turned off within 10 ms of a latchup event.