si8410 Silicon Laboratories, si8410 Datasheet - Page 21

• Manufacturer Part Number: si8410
• Description: Single & Dual-channel Digital Isolators
• Manufacturer: Silicon Laboratories

4.2. Input and Output Characteristics
The Si841x and Si842x inputs and outputs are standard CMOS drivers/receivers. Table 12 details powered and
unpowered operation of the Si84xx.
4.3. RF Radiated Emissions
The Si841x and Si842x families use an 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, rather,
is due to a small amount of RF energy driving the isolated ground planes, which can act as a dipole antenna.
The unshielded Si8410 evaluation board passes FCC requirements. Table 13 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.
Notes:
V
I
1. VDDI and VDDO are the input and output power supplies. V
2. Powered (P) state is defined as 2.375 V < VDD < 5.5 V.
3. Unpowered (UP) state is defined as VDD = 0 V.
4. X = not applicable; H = Logic High; L = Logic Low.
Input
H
X
X
L
1,4
VDDI State
UP
P
P
P
1,2,3
VDDO State
Frequency
(GHz)
2.094
2.168
4.210
4.337
6.315
6.505
8.672
UP
P
P
P
Table 12. Si84xx Operation Table
Table 13. Radiated Emissions
1,2,3
Measured
(dBµV/m)
70.0
68.3
61.9
60.7
58.3
60.7
45.6
Preliminary Rev. 0.1
V
O
Output
H
L
L
L
FCC Spec
(dBµV/m)
1,4
74.0
74.0
74.0
74.0
74.0
74.0
74.0
I
and V
Normal operation.
Upon the transition of VDDI from unpowered to
powered, V
than 1 µs.
Upon the transition of VDDI from unpowered to
powered, V
than 1 µs.
O
are the respective input and output terminals.
Compared to
Spec (dB)
–12.1
–13.3
–15.7
–13.3
–28.4
–4.0
–5.7
O
O
returns to the same state as V
returns to the same state as V
Comments
Si8410/20/21
I
I
in less
in less
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