bcm48bf120t300a00 Vicor Corporation, bcm48bf120t300a00 Datasheet - Page 14

• Manufacturer Part Number: bcm48bf120t300a00
• Description: Bcm™ Bus Converter
• Manufacturer: Vicor Corporation

PRELIMINARY DATASHEET
12.0 CURRENT SHARING
The performance of the SAC™ topology is based on efficient
transfer of energy through a transformer without the need of
closed loop control. For this reason, the transfer characteristic
can be approximated by an ideal transformer with a positive
temperature coefficient series resistance.
This type of characteristic is close to the impedance
characteristic of a DC power distribution system both in
dynamic (AC) behavior and for steady state (DC) operation.
When multiple BCM™ modules of a given part number are
connected in an array they will inherently share the load
current according to the equivalent impedance divider that the
system implements from the power source to the point of load.
Some general recommendations to achieve matched array
impedances include:
For further details see
in High Power
Figure 16 — BCM™ module array
v i c o r p o w e r. c o m
• Dedicate common copper planes within the PCB
• Provide as symmetric a PCB layout as possible among modules
• Apply same input / output filters (if present) to each unit.
+
to deliver and return the current to the modules.
Vin
DC
Arrays.
Z
Z
Z
IN_EQ1
IN_EQ2
IN_EQn
AN:016 Using BCM™ Bus Converters
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
BCM1
BCM2
BCMn
R
R
R
0_1
0_2
0_n
Z
Z
Z
OUT_EQ1
OUT_EQ2
OUT_EQn
Vout
Load
13.0 FUSE SELECTION
In order to provide flexibility in configuring power systems
V
of V
provide thermal protection in case of catastrophic failure.
The fuse shall be selected by closely matching system
requirements with the following characteristics:
• Current rating (usually greater than maximum current
• Maximum voltage rating (usually greater than the maximum
• Ambient temperature
• Nominal melting I
• Recommend fuse: <= 10A Littlefuse Nano
14.0 REVERSE OPERATION
BCM modules are capable of reverse power operation. Once
the unit is started, energy will be transferred from secondary
back to the primary whenever the secondary voltage exceeds
VIN • K. The module will continue operation in this fashion for
as long as no faults occur.
The BCM48BF120T300A00 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 output and transient
voltages appear on the input. Transient reverse power
operation of less than 10 ms, 10% duty cycle is permitted and
has been qualified to cover these cases.
•
of BCM module)
possible input voltage)
I Chip™ modules are not internally fused. Input line fusing
•
I Chip products is recommended at system level to
2
BCM
t
48
B
x 120
2
Fuse.
y
300A00
Page 14 of 18
Rev. 1.2
7/2011