PYD20 Manual
DC-DC Converter Isolated, 20W, 2x1”, PCB Mount
7. R
ECOMMENDED
W
IRING
S
CHEME
PYD
DC-DC
Converter
+Vout
-Vout
+Vin
-Vin
Load
TVS
FUSE
EMI Filter
DC
Source
+
+
-
D1
D2
F1
C1
Fuse F1:
The DC-DC converter is not internally fused. An external input fuse must always be used. Use a
3.15A slow-blow fuse.
Diode D1:
The diode provides a reverse input polarity protection. In case of a reversed polarity, the fuse will
open and protect the converter.
In applications where the input voltage can be reversed, it is advisable to install such a protection. Schottky
diodes are most suitable for this purpose. The current should be at least 1.5 times the tripping current of the
fuse. The voltage rating of the diode should be at least equal to the maximum possible input voltage.
Capacitor C1 and Diode D2:
These two components provide higher transient resistance (surge and burst)
at the input and are required if the DC-DC converter has to meet the EN61000-4-4 and EN61000-4-5
standard. The capacitor should be 220µF and the suppressor diode should be a SECOS SMDJ180A-C.
EMI Filter:
This filter reduces the conducted emission to the input. Circuit examples for a class A filter can
be found in the chapter "EMC Considerations".
All parameters are typical values specified at nominal input voltage, nominal output load, 25°C ambient and after a 5 minutes run-in time unless
otherwise noted. The information presented in this document is believed to be accurate and reliable and may change without notice.
For additional information, please visit
https://product.tdk.com/en/power/py
.
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