STMicroelectronics’ common-mode filters ensure signal integrity in serial interfaces

New common-mode filters from STMicroelectronics have an extremely wide differential bandwidth of 10.7GHz to protect antenna sensitivity in adjacent wireless circuitry from the latest serial digital interfaces.

The 2-channel ECMF2-40A100N10 and 4-channel ECMF4-40A100N10 are compatible with high-speed interface standards including USB 3.2 Gen 2, USB4, HDMI 2.1, and DisplayPort. With their low serial resistance of just 3Ω, which minimizes eye-diagram distortion, the filters preserve signal integrity.

The filters deliver deep common-mode attenuation (Scc21) from 2.4GHz to 7GHz, reaching -21dB at 5GHz, and effectively prevent interference with Wi-Fi and Bluetooth receivers.

In addition to tackling antenna de-sensitivity issues, the filters can be used for general interface-noise reduction to ensure compliance with electromagnetic compatibility (EMC) regulations. ESD protection up to ±9kV (contact discharge) and ±20kV (air discharge) is also built-in, which exceeds IEC 61000-4-2 level 4.

Both filters are housed in compact micro quad flat no-lead (µQFN) packages only 0.5mm high and are suited to demanding industrial applications as well as consumer products. They are well suited to protect smart factory equipment, imaging systems, medical devices, laboratory equipment, home-automation systems, set-top boxes, smart televisions, game consoles, notebooks, tablets, and docking stations.

Evaluation boards are available and offer a choice of SMA connector or USB-C connector to provide a convenient connection to test equipment for exploring the filters’ performance.