ST integrates CMF and ESD suppression in automotive-protection devices

STMicroelectronics’ ECMF04-4HSM10Y and ECMF04-4HSWM10Y automotive-qualified common-mode filters (CMF) for high-speed serial buses are able to protect interface ICs by integrating transient-suppression diodes with low clamping voltage.

According to ST these are the first CMFs on the market with automotive-grade qualification and automotive surge compliance guaranteed. They are not only produced and qualified according to AEC-Q101 requirements but have also been designed and tested against automotive surge specifics such as ISO10605.

The filters replace discrete common-mode chokes or LTCC (low-temperature cofired ceramic) devices that tend to be typically larger and provide no ESD protection. Essential for reliable functioning of Advanced Driver Assistance Systems (ADAS), they are placed on high-speed data lines for camera, radar, display, multimedia and other connections to prevent interference with wireless-communication equipment.

With a 3.5mm2 footprint, and 0.75mm high, the devices save board space, simplify design, and lower bill-of-materials costs.

The ECMF04-4HSM10Y has 2.2GHz differential bandwidth to suppress common-mode noise on HDMI 1.4, MIPI, and connections. Deep attenuation, reaching -25dB at 900MHz and -14dB at 1.5GHz, prevents radiated noise from reducing the sensitivity of cellular and GPS antennas.

The wider 3.5GHz bandwidth of the ECMF04-4HSWM10Y extends the application range to LVDS, DisplayPort, USB 3.1, and HDMI 2.0 buses. With -30dB attenuation at 2.4GHz and -16dB at 5.0GHz, the ECMF04-4HSWM10Y protects Bluetooth equipment and V2X (vehicle-to-everything) Wi-Fi antennas, as well as cellular and GPS systems.