| Previous experiments and research have indicated rectification of modulated electromagnetic interference can cause upset effects in digital electronics. Although RF rectification has been observed in discrete components, only speculation of the most sensitive mechanisms causing RF rectification has been proposed.; Through theoretical analysis, experiments, and simulations, the p-n junctions in ESD protection circuits were determined to be very susceptible to rectifying pulse modulated RF signals. Threshold experiments on several logic families of CMOS inverters provided indications to susceptibilities of electronics based on their input ESD protection topology.; High frequency port measurements were performed identifying resonances between 500 MHz and 1.5 GHz due to inductances from bonding wires and the voltage dependent junction capacitances of the ESD protection circuits. Parasitic elements have also been determined to help promote additional effects including bias shifts, state changes, RF gain, and undesirable circuit resonances.; DC and high frequency parameter extraction techniques were used to build diode and generic inverter models including package parasitics in PSPICE. Models were designed which gave good agreement to measured rectification drive curves, input impedance resonances, output voltage bias shifts, and induced spurious oscillations. |
