Study of board-level noise filters to prevent transient-induced latchup in CMOS integrated circuits during EMC/ESD test

Different types of board-level noise filters are evaluated for their effectiveness to improve the immunity of CMOS ICs against transient-induced latchup (TLU) under system-level electrostatic discharge (ESD) test. By choosing proper components in each noise filter network, the TLU immunity of CMOS ICs can be greatly improved. All the experimental evaluations have been verified in test chips with the silicon controlled rectifier (SCR) fabricated in a 0.25-mum CMOS technology. Some of such board-level solutions can be further integrated into the chip design to effectively improve TLU immunity of CMOS IC products