BCM4414XD1E5135YZZ Datasheet, PDF (21/41 Pages) Vicor Corporation – Isolated Fixed-Ratio DC-DC Converter

BCM4414xD1E5135yzz
V_HI
+ _DC
Z_{HI_EQ1}
Z_{HI_EQ2}
BCM^®1
R_{0_1}
Z_{LO_EQ1}
V_LO
BCM^®2
R_{0_2}
Z_{LO_EQ2}
Load
Z_{HI_EQn}
BCM^®n
R_{0_n}
Z_{LO_EQn}
Figure 24 — BCM module array
Fuse Selection
In order to provide flexibility in configuring power systems, BCM in
a VIA package modules are not internally fused. Input line fusing of
BCM in a VIA package products is recommended at system level to
provide thermal protection in case of catastrophic failure.
The fuse shall be selected by closely matching system
requirements with the following characteristics:
n Current rating
(usually greater than maximum current of BCM module)
n Maximum voltage rating
(usually greater than the maximum possible input voltage)
n Ambient temperature
n Nominal melting I²t
n Recommend fuse: 10A Littlefuse 505 Series or
10A Littlefuse 487 Series (HI side)
Reverse Operation
BCM modules are capable of reverse power operation. Once the
unit is started, energy will be transferred from low voltage side
back to the high voltage side whenever the low side voltage
exceeds V_HI • K. The module will continue operation in this fashion
for as long as no faults occur.
The BCM4414xD1E5135yzz has not been qualified for continuous
operation in a reverse power condition. Furthermore fault
protections which help protect the module in forward operation
will not fully protect the module in reverse operation.
Transient operation in reverse is expected in cases where there is
significant energy storage on the low voltage side and transient
voltages appear on the high voltage side.
Dielectric Withstand
The chassis of the BCM in a VIA Package is required to be
connected to Protective Earth when installed in the end application
and must satisfy the requirements of IEC 60950-1 for
Class I products.
The BCM in a VIA Package contains an internal safety approved
isolating component (VI ChiP) that provides the Reinforced
Insulation from high voltage side to low voltage side. The isolating
component is individually tested for Reinforced Insulation from
high voltage side to low voltage side at 4242V_DC prior to the final
assembly of the VIA™. When the VIA™ assembly is complete the
Reinforced Insulation can only be tested at Basic Insulation values
as specified in the electric strength Test Procedure noted in clause
5.2.2 of IEC 60950-1.
Test Procedure Note from IEC 60950-1
“For equipment incorporating both REINFORCED INSULATION and
lower grades of insulation, care is taken that the voltage applied
to the REINFORCED INSULATION does not overstress BASIC
INSULATION or SUPPLEMENTARY INSULATION.”
Summary
The final VIA assembly provides basic insulation from high voltage
side to case, reinforced insulation from high voltage side to low
voltage side and functional insulation from low voltage side to
case. Both sides of the housing are required to be connected to
Protective Earth to satisfy safety and EMI requirements. Protective
earthing can be accomplished through dedicated wiring harness
(example: ring terminal clamped by mounting screw) or surface
contact (example: pressure contact on bare conductive chassis or
PCB copper layer with no solder mask).
The case is required to be connected to protective earth in the
final installation. The construction of the VIA can be summarized
by describing it as a “Class II” component installed in a “Class I”
subassembly. The insulation from high voltage side to low voltage
side can only be tested at basic insulation values on the completely
assembled VIA product.
VI ChiP Isolation
High voltage side
Low voltage side
SELV
­
RI
Figure 25 — VI Chip before final assembly in the VIA
BCM^® in a VIA Package
Page 21 of 41
Rev 1.4
09/2016
vicorpower.com
800 927.9474