SI8440 SILABS [Silicon Laboratories], SI8440 Datasheet - Page 18

• Manufacturer Part Number: SI8440
• Description: QUAD-CHANNEL DIGITAL ISOLATOR
• Manufacturer: SILABS [Silicon Laboratories]

Si8440/1/2
4.5. RF Radiated Emissions
The Si8440 family uses a RF carrier frequency of approximately 2.1 GHz. This will result in a small amount of
radiated emissions at this frequency and its harmonics. The radiation is not from the IC chip but due to a small
amount of RF energy driving the isolated ground planes which can act as a dipole antenna.
The unshielded Si8440 evaluation board passes FCC requirements. Table 10 shows measured emissions
compared to FCC requirements.
Radiated emissions can be reduced if the circuit board is enclosed in a shielded enclosure or if the PCB is a less
efficient antenna.
18
Frequency
(GHz)
2.094
2.168
4.210
4.337
6.315
6.505
8.672
Table 10. Radiated Emissions
Measured
(dBµV/m)
70.0
68.3
61.9
60.7
58.3
60.7
45.6
Rev. 0.3
FCC Spec
(dBµV/m)
74.0
74.0
74.0
74.0
74.0
74.0
74.0
Compared
to Spec
–12.1
–13.3
–15.7
–13.3
–28.4
(dB)
–4.0
–5.7