Study of Radiated Emission from an Automotive Touchscreen System – A Simulation Driven Approach

Capacitive touchscreens offer an intuitive and robust interface that increase product reliability by eliminating mechanical parts. However, such systems contribute to Electromagnetic Interference (EMI) and Electromagnetic Compatibility (EMC) issues, such as Radiated Emissions (RE). In this paper, a simulation-based approach is presented to predict RE performance of a capacitive touchscreen system (TSG6XL) in a CISPR 25 environment. The simulation results are correlated with measurement. The simulation setup is then used to study the effect of transmitter excitation characteristics like slew rate, spread spectrum and position with respect to antenna. The emission contribution from PCB, cable and screen is also studied. Such a simulation driven approach therefore may be adopted for optimization of such systems in Design for EMC.