automotive

From the time when automotive vehicles were essentially mechanical with spark ignition the only electrical system, through the many decades that brought the development of electrical, electronic and computer controlled automotive systems, the need for and methods of automotive testing have evolved along with the vehicles. At one time, electrical testing was sufficient. But with the dawn of the digital computer era, compatibility became a major issue. Those pesky clocked systems are inherently noise producers and are also subject to immunity issues.

Due to increasing concerns with petroleum usage and the increasing federal fuel economy regulations, electric powertrains have become more accepted by automotive manufacturers and can be found in production and within numerous development programs.

TÜV SÜD America is pleased to announce the expansion of their automotive EMC laboratory with the opening of an additional 3-meter chamber for immunity and emission testing along with expanded conducted immunity capacity and capabilities.

A case study describing the influence of TFT LCD graphics on automotive radiated emissions testing and its impact to the FM band receiver. The underlying root-cause of the EMI issue is determined using a novel technique that decodes the display’s graphics into the transmitted RGB data and predicts the data’s impact to radiated emissions. The countermeasure implemented to resolve the issue is equally novel and does not involve any hardware optimizations. The use of test images to be used in component level EMC testing is also discussed.

Electromagnetic interference (EMI) filters are often used on automotive 13.8 VDC power networks to reduce high-frequency noise from being conducted off the printed circuit boards (PCB) and resulting into EMI problems. The filter performance is difficult to predict and often compromised at high frequencies due to parasitics associated with the filter itself, or the PCB layout. The power line filters with Surface Mount Technology ferrite and Multi Layer Ceramic Capacitors are attractive solutions for mitigation of RF noise in high-density automotive PCBs. A lumped-element SPICE model is introduced for optimized π-filter design, including frequency-dependent ferrite component model. The PCB implementation of EMI filter is outlined for optimum filter performance.