DocID026512 Rev 1

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AN4540

Solutions offered by STMicroelectronics

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Figure 8. Common mode attenuation comparison

The attenuation in the GSM frequencies and the clock signal integrity are very difficult to get

due to the technology with CMF standard. Indeed, the attenuation curve has to be translated

into high frequencies, limiting the attenuation performance in the frequency range.

ESD protection on the data lines as well as on CBUS line is a benefit given by the ECMF02-

3HSM6. Its sharp clamping allows the transmitter to be protected against various surges

such as ESD strikes. Furthermore, clamping robustness is guaranteed for more than one

thousand discharges. Figure 9 shows the clamping response comparison between the

ECMF02-3HSM6 and CMF including MOV devices at 8 kV in contact mode. Clamping levels

are much better with the silicon solution. Moreover, the difference is more important when

ESD strike level is lower.

Figure 10 shows responses at 1 kV.