Circuit-level electrothermal simulation techniques for designing output protection devices

The design of I/O protection circuits is crucial for the reliable operation of integrated circuits. Typical protection circuits are designed to meet certain specifications (ESD/EOS failure levels) and the use of CAD tools in the design stage will help in their characterization and design. We recently developed a circuit-level electrothermal simulator, iETSIM, which we have used to study different protection circuit designs. iETSIM solves the heat diffusion equation simultaneously with the device electrical equations. The device models extend to the avalanche breakdown regime. We show that the circuit-level electrothermal simulator can be a useful tool for designing reliable output protection devices.