Design on ESD protection circuit with very low and constant input capacitance

Effective on-chip ESD design to solve the ESD protection challenge on the analog pins for high-frequency or current-mode applications is studied. The device dimension of ESD clamp devices in analog ESD protection circuit can be reduced to have a much small input capacitance for high-frequency applications, but it can still sustain a high HBM and MM ESD level. To find the optimized device dimensions and layout spacings on ESD clamp devices, a design model is developed to keep the input capacitance as constant as possible (within 1% variation).