Evaluation on Board-Level Noise Filter Networks to Suppress Transient-Induced Latchup in CMOS ICs Under System-Level ESD Test

Different types of board-level noise filter networks are evaluated to find their effectiveness for improving the immunity of CMOS ICs against the transient-induced latchup (TLU) under the 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 with the silicon-controlled rectifier (SCR) test structures and the ring oscillator circuit fabricated in a 0.25-/spl mu/m CMOS technology. Some board-level solutions can be further integrated into the chip design to effectively improve the TLU immunity of CMOS IC products.