High bandwidth, common mode filters serve multi-Gbit serial interfaces
Common-mode filters from STMicroelectronics have a wide differential bandwidth of 10.7GHz to protect antennas in adjacent wireless circuitry. The two-channel ECMF2-40A100N10 and four-channel ECMF4-40A100N10 are compatible with high-speed interface standards including USB 3.2 Gen 2, USB4, HDMI 2.1 and DisplayPort.
The common mode filters have low serial resistance of just 3.0 Ohms, which minimises eye diagram distortion, to preserve signal integrity. The filters deliver deep common-mode attenuation (Scc21) from 2.4 to 7.0GHz, reaching -21dB at 5.0GHz, and effectively prevent interference with Wi-Fi and Bluetooth receivers, added ST.
In addition to tackling antenna de-sensitivity issues, the filters can be used to reduce general interface noise to ensure compliance with electromagnetic compatibility (EMC) regulations. Electrostatic discharge (ESD) protection up to ±9kV (contact discharge) and ±20kV (air discharge) is also built-in. This level of protection exceeds IEC 61000-4-2 level 4, ST added.
Both filters are housed in compact micro quad flat no-lead (µQFN) packages which are just 0.5mm high. They are suitable for demanding industrial applications as well as consumer products and can be used in 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 with a choice of SMA connector or USB-C connector.
The ECMF2-40A100N6 is supplied in a 1.35 x 1.4mm six-lead µQFN-6L and the ECMF4-40A100N10 is in a 1.35 x 2.2mm 10-lead µQFN-10L. Both filters are in production now.