DocID026512 Rev 1

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AN4540

Solutions offered by STMicroelectronics

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Solutions offered by STMicroelectronics

The ECMF02-3HSM6 is a common mode filter including ESD protection (see Figure 4).

Figure 4. ECMF02-3HSM6 schematic

It complies with the MHL standard; its differential bandwidth fulfills the eye diagram template

up to MHL 2.0. Figure 5 shows an example at 3 Gbps.

Figure 5. MHL 2.0 eye diagram template, data rate 3 Gbps (1080 p/60 Hz)

This device offers a good common mode rejection. Figure 6 shows the spectral content

comparison between the standard common mode filter and the ECMF02-3HSM6 without

filtering. This device is placed on a differential link at 2.25 Gbps where the skew is present,

due to different trace lengths. The difference on the noise level in the frequency range (700

MHz to 1 GHz) goes up to 15 dB, which is not negligible when the designer has some

antenna desense issues in a mobile application.