Abstract: This paper discusses the similarities and differences between the latch-up induced by electrics and the latch-up induced by radiation for CMOS IC's. A technical scheme for Latch-up protection based on current rejection by a low-dropout linear voltage regulator(LDO) is developed, with the onboard experimental result and the experimental data of TDO on ground of the LDO circuit used on the satellite given. Finally, the problem of protection and recovery from latch-up on the onboard-computer has been solved.

Key words: onboard computer, space radiation, protection from latch-up, linear voltage regulator