Datasheet
ULS 100-Watt Series
Sixteenth-brick DOSA-Compatible,
Isolated DC-DC Converters
MDC_ULS-100 Series.A09 Page 19 of 28
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Emissions Performance, Model ULS-12/8.3-D48
Murata Power Solutions measures its products for radio frequency emissions
against the EN 55022 and CISPR 22 standards. Passive resistance loads are
employed and the output is set to the maximum voltage. If you set up your
own emissions testing, make sure the output load is rated at continuous power
while doing the tests.
The recommended external input and output capacitors (if required) are
included. Please refer to the fundamental switching frequency. All of this
information is listed in the Product Specifi cations. An external discrete fi lter is
installed and the circuit diagram is shown below.
[1] Conducted Emissions Parts List
[2] Conducted Emissions Test Equipment Used
Hewlett Packard HP8594L Spectrum Analyzer –S/N 3827A00153
2Line V-networks LS1-15V 50 /50Uh Line Impedance Stabilization Network
[3] Layout Recommendations
Most applications can use the fi ltering which is already installed inside the
converter or with the addition of the recommended external capacitors. For
greater emissions suppression, consider additional fi lter components and/or
shielding. Emissions performance will depend on the user’s PC board layout,
the chassis shielding environment and choice of external components. Please
refer to Application Note GEAN-02 for further discussion.
Since many factors affect both the amplitude and spectra of emissions, we
recommend using an engineer who is experienced at emissions suppression.
[3] Conducted Emissions Test Results
Reference
Reference
Part Number
Part Number
Description
Description
Vendor
Vendor
C1 GRM32ER72A105KA01L
SMD CERAMIC
100V-1000nF-X7R-1210
Murata
C2 GRM319R72A104KA01D
SMD CERAMIC
100V-100nF-±10%-X7R-1206
Murata
L1 LB16H1324
COMMON MODE
1320uH-±25%-4A-R5K-21 *21*12.5mm
High
Light
C4, C5 GRM32DR73A223KW01L
SMD CERAMIC
1000V-0.022uF-±10%-X7R-1210
Murata
C3 UHE2A221MHD
Aluminum
100V-320Uf-±10%-long lead
Nichicon
C6 NA
C2
L1
C6C3C1
Vin+ Vout+
Vout-Vin-
Black
DC Source
Resistive Load
inside a metal
container
Test Card
UUT
Resistive Load
V-
V+
L2
C5
C4
Figure 5. Conducted Emissions Test Circuit
Graph 5. Conducted emissions performance, Positive Line,
CISPR 22, Class A, 48Vin, full load
Graph 6. Conducted emissions performance, Negative Line,
CISPR 22, Class A, 48Vin, full load