Choke for Automotive Power over Coax

TDK Corporation has announced the ADL3225V choke for automotive power over coax (PoC) applications. The wire wound inductor, which has a dc resistance of 0.9Ω, features high impedance over a broad frequency spectrum of 1MHz up to 1GHz. The new type offers good dc superimposition characteristics, thus separating the power from the signal path, for example, for the signals of sensors and cameras that are connected via automotive Ethernet.

The rated inductance of the choke is 47µH and their rated current (Isat) is 300mA. The new choke, which is qualified to AEC-Q200, is available with compact dimensions of 3.2mm x 2.5mm x 2.4mm. Mass production of the ADL3225V is scheduled to begin in April 2017.

PoC applications require high impedance at the branch of the power line and the signal line in order to prevent the high-frequency signal from causing interference on the power line with its low load impedance. TDK's proprietary structural design and winding combined with the fully automated manufacturing process ensures the excellent electrical properties and high reliability of the new inductors.

The growing number of sensors and cameras in cars is driving the need to speed up the communications between the many ECUs. Advanced communication protocols such as automotive Ethernet with a data rate of up to 100 Mbit/s and low-voltage differential signaling with a transmission rate of up to 1.5 Gbit/s) are both being used for the image signals from on-board camera to the main circuit board. PoC, in which both the data and power are transmitted simultaneously over the same coaxial cable, serves to reduce the weight of wire harnesses and improve fuel consumption.