Automotive Ethernet filter achieves class IV parasitic capacitance

TDK Corporation announces that it has expanded its lineup of the ACT1210E Series (3.2 x 2.5 x 2.5 mm – L x W x T) of common mode filters for automotive Ethernet communication 10BASE-T1S. Mass production of this new common mode filter began this month, July 2024.

The new ACT1210E-131-2P-TL00 filter lowers the line-to-line capacitance by approximately 30% compared to conventional products. In the OPEN Alliance EMC test specification for common mode chokes, the part achieves Class IV status with the lowest parasitic capacitance – an industry first. The common mode inductance at 100 kHz is 130 µH, and the rated current is 70 mA.

The communication circuit of 10BASE-T1S has PHY, ESD suppression devices and other electronic components in addition to common mode filters, each of which has its own capacitance. As total capacity increases so does signal wave shape turbulence, which leads to disruptions in normal telecommunications. For this reason, engineers need to select components geared to low capacitance.

To achieve high S-parameters, the new product employs TDK’s proprietary design structure and optimized materials to reduce the impact of signal distortions caused by capacitance and effectively dampen common mode noise. Additionally, the original high-precision automatic winding technology ensures stable quality and high reliability.

TDK has an extensive lineup of common mode filters for automotive applications, including not only filters that are compliant with the currently mainstream CAN, CAN FD, and FlexRay protocols but also compliant with Ethernet protocols, such as 100BASE-T1 and 1000BASE-T1 for telecommunication speeds of 100 Mbps and 1 Gbps respectively. Moving forward, TDK will continue meeting the demands of customers by providing comprehensive product services for common-mode filters for automotive communication.