VI-ARM Datasheet, PDF (7/12 Pages) Vicor Corporation – Autoranging Rectifier Modules Up to 1500 Watts

Application Note, continued
N
15Vdc
ST
150kΩ
Micro-
controller
L
+V
BOK
EN
–V
Vicor
DC-DC
+In
Converter
Gate In (PC)
Vico
DC-D
Conver
Gate Out (PR)
–In
To additional modules
Figure 9—Enable (EN) function; See Fig.8 for details
N
15Vdc
ST
27kΩ
Micro-
controller
L
+V
BOK
EN
–V
+5 Vdc
Secondary
referenced
Vicor
DC-DC
+In Converter
Gate In (PC)
D
Co
Gate Out (PR)
–In
To additional modules
Figure 10—Bus OK (B OK) isolated power status indicator
L2/N
Z1 C1
L1 _F1
GND
R1
L1
R3
L2
R2
L3
C2
R4
C3
C4
Low power filter connections
Vicor
Part
Description Part Number
N
C1
1.0µF
02573
C2, C3 4700pF
01000
ST
C4
0.15µF
03269
F1
12A fuse
05147
L
L1, L2
27µH
14563
L3
1.3mH
15016
R1, R2 10Ω
R3
150kΩ, 0.5W 00127-1503
R4
2.2Ω
Z1
MOV
03040
L2/N
Z1
L1
F1
R2
10
1/2W
C1
390K
R1
L3
1/2W
L1
L2
GND
High power filter connections
Figure 11—Filter connections
C3
4700pF
C2
4700pF
L4
N
C4
4700pF
C6
.22µF
ST
C5
(X2)
4700pF
L
Part
L1,L4
L2, L3
C1
C2,C3,C4,C5
C6
R1
R2
F1
Z1
Description
1000µH 12A/6.5MΩ
22µH
.68µf (x type)
4700pf
.22µf (x type)
390k ¹/2 W
10Ω ¹/2 W
17A/250V
MOV
Vicor
Part Number
02134
11479
02573
03285
04068
03040
Bus-OK (B OK) Pin. (See Fig. 10). The Bus-OK pin is
intended to provide early-warning power fail information
and is also referenced to the negative output pin.
Caution: There is no input to output isolation in the ARM.
It is necessary to monitor Bus-OK via an optoisolator if it is to
be used on the secondary (output) side of the converters. A line
isolation transformer should be used when performing scope
measurements. Scope probes should never be applied
simultaneously to the input and output as this will destroy the unit.
Filter. Two input filter recommendations are shown for low
power VI-ARM-1 and high power VI-ARM-2 (See Fig. 11).
Both filter configurations provide sufficient common mode and
differential mode insertion loss in the frequency range between
100kHz and 30MHz to comply with the Level B conducted
emissions limit.
Hold-up Capacitors. Hold-up capacitor values should be
determined according to output bus voltage ripple, power fail
hold-up time, and ride-through time. (See Fig. 12). Many
applications require the power supply to maintain output
regulation during a momentary power failure of specified
duration, i.e., the converters must hold-up or ride-through such
an event while maintaining undisturbed output voltage
regulation. Similarly, many of these same systems require
notification of an impending power failure in order to allow time
to perform an orderly shutdown.
The energy stored on a capacitor which has been charged to
voltage V is:
ε = 1/2(CV²)
(1)
Where: ε = stored energy
C = capacitance
V = voltage across the capacitor
Energy is given up by the capacitors as they are discharged by
the converters. The energy expended (the power-time product)
is:
ε = P∆t = C(V₁₂–V₂₂) / 2
(2)
Where:
P = operating power
∆t = discharge interval
V₁ = capacitor voltage at the beginning of ∆t
V₂ = capacitor voltage at the end of ∆t
Rearranging equation 2 to solve for the required capacitance:
C = 2P∆t / (V₁₂–V₂₂)
(3)
Vicor Corp. Tel: [phone] Fax: [phone]
ARM, Autoranging Rectifier Module
Set your site on VICOR at www.vicorpower.com
Rev. 2.4
Page 7 of 12