Hardware-Simulation Correlation of BCI failures in Capacitive Touch Sensing Application using ICIM

Capacitive touch sensors are gaining in popularity as a preferred human machine interface. Ensuring proper functionality of such systems in the presence of conducted electromagnetic interference is a design challenge. The Bulk Current Injection (BCI) method is widely used for such RF immunity testing particularly for automotive systems. If detected at a late stage, compliance failures may lead to expensive redesigns and increased time to market. Therefore, there is an urgent need to improve the prediction of BCI failures at the early design cycle. In this work, first, a methodology is proposed to generate an immunity model for the capacitive sensor IC, as a one-time process from DPI and VNA measurements. Then, a BCI simulation methodology is outlined using hybrid electromagnetic and circuit simulation and embedding the generated IC immunity model. A test-board is built and hardware-simulation correlation is performed. Results indicate reasonable accuracy in prediction using the proposed methodology.