PRELIMINARY
Configuration Options (Cont.)
21.5
0.85
22.0
0.87
32.0
1.26
32.0
1.26
14.0
0.56
11.7
0.46
ON–BOARD MOUNT
with 0.25'' Pin Fins
IN–BOARD MOUNT
with 0.25'' Pin Fins
(V•I Chip recessed into PCB)
mm
in
mm
in
Figure 22— In-board with pin fins – package L
Figure 23— On-board with pin fins – package G
Input reflected ripple
measurement point
F1
7 A
Fuse
+
Load
–
+Out
–Out
+In
R1
Enable/Disable Switch
0.30 Ω
R3
0.1 Ω
C2
PC
SG
0.47 µF
R2
C1
ceramic
2K Ω
8 µF
BCM
ceramic
C3
1 µF
ceramic
D1
SW1
TM
–In
+
–
Temperature Monitor
Notes:
Source inductance should be no more than 200 nH. If source inductance is
greater than 200 nH, additional bypass capacitance is required.
C3 should be placed close to the load.
D1 power good indicator will dim when a module fault is detected.
TM should always be referenced to SG.
Figure 24—BCM test circuit
Application Note
Parallel Operation
The BCM will inherently current share when properly
configured in an array of BCMs. Arrays may be used for
higher power or redundancy in an application.
delivered to the load is larger than that sourced from the input,
allowing traces to be utilized on the input side if necessary. The
use of dedicated power planes is, however, preferable.
Current sharing accuracy is maximized when the source and
load impedance presented to each BCM within an array are equal.
The BCM power train and control architecture allow
bi-directional power transfer, including reverse power
processing from the BCM output to its input. Reverse power
transfer is enabled if the BCM input is within its operating
range and the BCM is otherwise enabled. The BCM’s ability to
process power in reverse improves the BCM transient response
to an output load dump.
The recommended method to achieve matched impedances is to
dedicate common copper planes within the PCB to deliver and
return the current to the array, rather than rely upon traces of
varying lengths. In typical applications the current being
Vicor Corporation
Tel: 800-735-6200
V•I Chip Bus Converter
B048K120T15
Rev. 1.2
Page 11 of 16
45 vicorpower.com
VICOR [ VICOR CORPORATION ]
