Application Note (continued)
Input reflected ripple
measurement point
F1
10 A
Fuse
Notes:
+Out
-Out
+
Load
–
+In
Source inductance should be no more than 200 nH. If source inductance is
greater than 200 nH, additional bypass capacitance may be required.
Enable/Disable Switch
R3
10 mΩ
C1
47 µF
electrolytic
TM
C3 should be placed close to the load.
BCM™
R2
RSV
PC
2 kΩ
C3
3.3 µF
+Out
-Out
D1
R3 may be ESR of C3 or a separate damping resistor.
D1 power good indicator will dim when a module fault is detected.
SW1
K
Ro
-In
Figure 20 — BCM™ module test circuit
BCM™ Bus Converter Level 1 DC Behavioral Model for 48 V to 24 V, 300 W
ROUT
IOUT
43.6 mΩ
+
+
1/2 • Iout
1/2 • Vin
•
V I
+
–
+
–
VOUT
VIN
IQ
83 mA
K
–
–
©
Figure 21 — This model characterizes the DC operation of the bus converter, including the converter transfer function and its losses. The model enables estimates
or simulations of output voltage as a function of input voltage and output load, as well as total converter power dissipation or heat generation.
BCM™ Bus Converter Level 2 Transient Behavioral Model for 48 V to 24 V, 300 W
3.44 nH
Lout 1.1 nH
IOUT
ROUT
LIN = 5 nH
43.6 mΩ
+
+
R
COUT
R
11.13 mΩ
1/2 • Vin
CIN
V•I
K
1 mΩ
1.3 mΩ
1/2 • Iout
+
–
1.9 µF
7.7 µF
+
–
CIN
COUT
VOUT
VIN
IQ
83 mA
–
–
©
Figure 22 — This model characterizes the AC operation of the bus converter including response to output load or input voltage transients or steady state
modulations. The model enables estimates or simulations of input and output voltages under transient conditions, including response to a stepped load with or
without external filtering elements.
vicorpower.com
800-735-6200
BCM™ Bus Converter
B048F240T30
Rev. 2.8
Page 11 of 12
VICOR [ VICOR CORPORATION ]
