Common Mode Choke Coil for In-vehicle Use
While the use of electronic components in automobiles has been accelerated, strategies against noise have been becoming increasingly important for the assurance of safety.Murata has been developing automotive components for noise suppression, using its magnetic material and magnetic circuit design technologies gained through the development of noise suppression components for consumer products, as well as its unique winding technology.
Trends improved fuel efficiency following environmental regulations and the advancement of driving assistance systems have increased the number of ECUs*1 per car, thereby making faster automotive LANs increasingly sought-after systems. Because the in-vehicle LAN cables connecting these ECUs tend to generate radio interference and are susceptible to external noise, noise suppression becomes imperative. To make components suitable for this kind of environment, Murata has been developing high-reliability common mode choke coils (CMCC) that are excellent in suppressing noise. CMCCs are capable of suppressing only common mode noise, based on the difference of conduction properties that depend on modes. To maximize this capability, Murata’s unique design technology and sophisticated winding technology are essential.
We would like to present typical examples of automotive CMCCs here below.
(1) CMCCs suitable to in-vehicle LAN, such as CAN, FlexRay
Typified by CAN*2 and FlexRay*3, in-vehicle LANs have relatively slow signal speed, radiating noise in a broad range of frequency, from low to high frequencies (RF). From a safety point of view, these LANs are required to possess high immunity to prevent malfunctions of automotive equipment due to noise. In order to accommodate such a requirement, the DLW32SH series have about 50% reduced volume compared with the DLW43SH_XK series, which was made possible by the circuit design technology with enhanced magnetic efficiency, and yet still have the same common mode inductance lineup as the existing products. At the same time, the adopted metal terminal structure has allowed users to use the products under broader operating temperature ranging from -55℃ to 150℃.
(2) CMCCs suitable for in-vehicle Ethernet BroadR-Reach®
The DLW43SH_MH series are CMCCs that are suitable for in-vehicle Ethernet BroadR-Reach®*4, the application of which is being developed for On-Board Diagnostics (OBD) systems, in-vehicle camera systems, and backbone systems. The product has accomplished low insertion losses with Murata’s unique ferrite material technology, and finer mode conversion with Murata’s sophisticated winding technology. These characteristics give the products high noise suppression effect and high immunity response. We will continue to develop the products that will be able to accommodate various needs of noise suppression from now on.
In-Vehicle Common Mode Choke Coils (CMCC)
In-Vehicle CMCC for Ethernet BroadR-Reach®
Application
Structure
Electrical characteristics
Glossary
*1 ECU (Electronic Control Unit):
A generic term for electronic control circuits.
*2 CAN (Controller Area Network):
A type of network protocol used in automobiles. It is a standard protocol used in automobiles today. Its signal speed is 1Mbps.
*3 FlexRay:
A kind of network communication protocol used in automobiles. Faster communication speed and real-time processing make it also suitable for directly controlling an automobile (brakes, steering, etc.). Its signal speed is 10Mbps.
※FlexRay is a trademark or registered trademark of Daimler Chrysler AG in Japan and other countries.
*4 BroadR-Reach®:
A basic technology of in-vehicle Ethernet standard designated by OPEN Alliance SIG. Its signal speed is 100Mbps.