nph10s C&D Technologies., nph10s Datasheet - Page 5

• Manufacturer Part Number: nph10s
• Description: Isolated 10w Single Output Dc/dc Converters
• Manufacturer: C&D Technologies.

EMC FILTERING AND SPECTRA
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FILTERING
The module includes a basic level of filtering, sufficient for many applications. Where lower noise levels are desired, filters can easily be added to achieve any required
noise performance.
A DC/DC converter generates noise in two principle forms: that which is radiated from its body and that conducted on its external connections. There are three separate
modes of conducted noise: input differential, output differential and input-output.
This last appears as common mode at the input and the output, and cannot therefore be removed by filtering at the input or output alone. The first level of filtering is to
connect a capacitor between input and output returns, to reduce this form of noise. It typically contains high harmonics of the switching frequency, which tend to appear
as spikes on surrounding circuits. The voltage rating of this capacitor must match the required isolation voltage. (Due to the great variety in isolation voltage and required
noise performance, this capacitor has not been included within the converter.)
Input ripple is a voltage developed across the internal Input decoupling capacitor. It is therefore measured with a defined supply source impedance. Although simple
series inductance will provide filtering, on its own it can degrade the stability. A shunt capacitor is therefore recommended across the converter input terminals, so that it
is fed from a low impedance.
If no filtering is required, the inductance of long supply wiring could also cause a problem, requiring an input decoupling capacitor for stability. An electrolytic will perform
well in these situations. The input-output filtering is performed by the common-mode choke on the primary. This could be placed on the output, but would then degrade
the regulation and produce less benefit for a given size, cost, and power loss.
Radiated noise is present in magnetic and electrostatic forms. The latter is suppressed by the metal case, which is connected to the output return, typically a zero-volt
point. Thanks to the small size of these units, neither form of noise will be radiated “efficiently”, so will not normally cause a problem. Any question of this kind usually
better repays attention to conducted signals.
EMC FILTER AND VALUES TO OBTAIN SPECTRA AS SHOWN
NPH10S2403
NPH10S2405
NPH10S2412
NPH10S2415
NPH10S4803
NPH10S4805
NPH10S4812
NPH10S4815
C1, C2 & C4 : Electrolytic capacitors
C3 : Polyester or ceramic capacitor
EMC Spectra red limit line is EN 55022 curve B Quasi-peak average limit.
C1
10µF 100V
10µF 100V
10µF 100V
10µF 100V
10µF 100V
10µF 100V
10µF 100V
10µF 100V
C2
47µF 63V
47µF 63V
Not required
10µF 63V
47µF 100V
47µF 100V
Not required
Not required
C3
2.2µF 63V
2.2µF 63V
470nF 63V
Not required
220nF 100V
220nF 100V
470nF 100V
470nF 100V
Component reference
C4
10µF 25V
10µF 25V
10µF 25V
10µF 25V
10µF 25V
10µF 25V
10µF 25V
10µF 25V
Isolated 10W Single Output DC/DC Converters
Technical enquiries - email: [e-mail], tel:
L1
MPS 18R333C
MPS 18R333C
MPS 18R333C
MPS 18R473C
MPS 18R104C
MPS 18R104C
MPS 18R104C
MPS 18R104C
47µH 1.65A
100µH 1.2A
100µH 1.2A
100µH 1.2A
100µH 1.2A
33µH 2A
33µH 2A
33µH 2A
L2
NPH10S Series
KDC_NPH10SC.I02 Page 5 of 8
L3
MPS 18R472C
4.7µH 5.35A
MPS 18R103C
10µH 3.45A
MPS 18R333C
33µH 2.00A
MPS 18R333C
33µH 2.00A
MPS 18R472C
4.7µH 5.35A
MPS 18R103C
10µH 3.45A
MPS 18R333C
33µH 2.00A
MPS 18R333C
33µH 2.00A
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