Approaches to radiated emissions reduction of powertrain control modules

Basic concepts and guidelines for design of an electromagnetically compliant automotive electronic system are available today. At the same time system-specific configurations sometimes make the final EMC behavior unpredictable. This contribution addresses some experimental approaches used for radiated emissions reduction from Motorola MPC500 family-based powertrain control modules. The applied approaches include analysis of possible noise sources in the microcontroller unit, reduction of core power supply coupling through high-speed PWB routing, application of low ESL decoupling capacitors, filtered connectors and the spread-spectrum clock generation (SSCG) technique. All approaches were validated by radiated emission measurements in a semi-anechoic chamber according to the CISPR 25 measurement technique. The adopted strategy allowed us to obtain the EMC compliant powertrain control module.