Miniaturised common-mode chokes for automotive Ethernet

TDK Corporation has released the ACT1210G-800-2P, a new type of common-mode choke that complies to the standards of the OPEN Alliance (One-Pair Ether-Net) for 1000BASE-T1. Due to the high values of the S-parameters, a high amplitude ratio is created between differential and common-mode levels – a decisive factor for signal integrity in the automotive Ethernet. The common-mode inductance at 100kHz is 80µH, and the maximum permissible current is 70mA.

Due to a metal frame for the connecting electrodes, the choke provides excellent thermal behaviour, allowing it to be employed within a broad temperature range from -40C to +125C. The new component is produced in a highly automated and extremely precise winding process which delivers high reliability and minimal scatter of the electrical parameters.

One specific feature is the compact size, with measurements of only 3.2mm x 2.5mm x 2.4mm, notably less than those of CAN-Bus orFlexRay chokes. This indicates that the new choke can be employed, for example, in automotive camera systems highlighting an ever-increasing packing density of components.