UG-1219 EVAL-ADUM5020EBZ User Guide
Rev. 0 | Page 4 of 8
CISPR22/EN55022 RADIATED EMISSIONS TEST
RESULTS
The EVAL-ADUM5020EBZ evaluation board design has been
tested to pass the CISPR22/EN55022 Class B standard. Table 3
provides a summary of the results. All CISPR22/EN55022 radiated
emissions tests were performed with the PCB schematic and layout
shown in Figure 5 to Figure 7.
The EVAL-ADUM5020EBZ evaluation board is configured and
tested with 5.0 V power supplied to the V
DDP
pin from the
ADP7104ACPZ regulator output. The ADP7104ACPZ regulator
input is supplied from a standard 9 V battery. V
ISO
can be loaded
with six 300 Ω, 0805 size, SMD resistors in parallel for a total
load of 50 Ω or 100mA load at 5 V. Measurements carried out
according to the CISPR22/EN55022 Class B standard in a semi
anechoic chamber at 10 m from 30 MHz to 1 GHz are shown in
Figure 3 and Figure 4. Figure 3 shows the results of the peak
horizontal scan (the worst case), and Figure 4 shows the results
of the peak vertical scan. Table 3 shows the tabulated quasi peak
(QP) results. These results show that the ADuM5020 emissions
at −4.0 dB margin are well below CISPR22/EN55022 Class B
limits when at 5 V output and 100 mA load on a 2-layer PCB
with the use of ferrites.
80
70
(dBµV/m)
60
50
40
30
20
10
0
30 100 1000
FREQUENCY (MHz)
EN55022 CLASS A
EN55022 CLASS B
16386-003
Figure 3. Horizontal Scan from 30 MHz to 1 GHz with 100 mA, 5 V Output
80
70
(dBµV/m)
60
50
40
30
20
10
0
30 100 1000
FREQUENCY (MHz)
EN55022 CLASS A
EN55022 CLASS B
16386-004
Figure 4. Vertical Scan from 30 MHz to 1 GHz with 100 mA, 5 V Output
Table 3. ADuM5020 Test Results (QP Measurements)
Frequency
(MHz)
QP Level
dB (μV/m)
Limit EN55022
Class B dB
(μV/m)
QP Margin from limit
EN55022 Class B dB
(μV/m)
Antenna
Position
Antenna
Height (m)
5 V In, 5 V Out
Output Current
(mA)
Pass/Fail
221.54 24.5 30 −5.5 Horizontal 4.0 100 Pass
335.81 32.0 37 −5.0 Horizontal 2.8 100 Pass
436.70 33.0 37 −4.0 Horizontal 2.0 100 Pass
436 25.0 37 −12.0 Vertical 2.0 100 Pass
