Vicor VI-J00 Family DC-DC Converters and Configurable Power Supplies - Manual (Page 98)

Design Guide & Applications Manual
For VI-200 and VI-J00 Family DC-DC Converters and Configurable Power Supplies
VI-200 and VI-J00 Family Design Guide Rev 3.5 vicorpower.com
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Apps. Eng. 800 927.9474 800 735.6200
Y
Y-Capacitor. Power conversion modules generally require
bypass capacitors from line to chassis (earth ground) to
shunt common-mode noise currents and keep them local
to the converter. In cases where the converters are
operating from rectified AC line voltage, the failure of a
bypass capacitor could result in excessive leakage current
to the equipment chassis thus creating a ground fault and
shock hazard. For this reason, a special classification of
capacitor, referred to as a Y-capacitor, is recommended.
These capacitors contain a dielectric with unique “self-
healing” properties to help prevent against excessive
leakage.
To meet general EMC requirements (Section 9), Vicor
recommends the use of Y-capacitors with all power
conversion modules. Y-capacitors meet IEC384-14,
EN132400, and UL1283 standards.
Z
Zero-Current-Switching. The turn-on and turn-off of a
switching device at zero current, resulting in essentially
lossless switching. The zero-current-switching topology
allows Vicor converters to operate at frequencies up to
1 MHz, with efficiencies higher than 80% and power
densities greater than conventional topologies.
Zero-Voltage-Switching. This technique significantly
minimizes the switching losses and dv/dt noise due to the
discharge of the switching MOSFET junction capacitance
and reverse recovery of the diode, and enables switch
mode converters to operate at higher frequencies.
26. Glossary of Technical Terms