Common mode filter for automotive signal lines
The TDK ACT1210G-800-2P-TL10 is a 2-line common mode filter from the ACT series, designed for signal-line EMI suppression in automotive and industrial applications. It presents 3.8 kOhms impedance at 10 MHz, which is the frequency band where conducted emissions from switching transients and data-line noise typically couple onto the power or signal pair.
AEC-Q200 qualification and operating envelope
Rated AEC-Q200, this filter is qualified for the automotive stress profile — temperature cycling, mechanical shock, and vibration per the AEC-Q200 passive-component standard. The 80V DC voltage rating and 70mA current rating define the signal rail it can sit on — suitable for 12V and 24V automotive buses where transients can exceed the nominal rail, and for low-current sensor or CAN lines where the common-mode choke must not saturate on the bias current.
At 3.8 kOhms and 10 MHz, the filter presents a high impedance to common-mode noise while the differential signal sees the 80 µH inductance at 100 kHz. The 2.6 Ohm maximum DCR drops about 182 mV at the 70mA rated current — a small voltage loss that matters if the downstream receiver has a tight input threshold.
Package and board integration
The 4-pad layout routes the two signal lines through the choke with the common-mode return path through the centre pads — a layout that requires the PCB designer to keep the differential pair symmetrical under the component to avoid mode conversion.