Download 7. Application Circuits / Converter Array Design Considerations

7. Application Circuits / Converter Array Design Considerations
Design Guide & Applications Manual
For VI-200 and VI-J00 Family DC-DC Converters and Configurable Power Supplies
Logic Disable. (Figure 7–1) The GATE IN pin of the
module may be used to turn the module on or off. When
GATE IN is pulled low (<0.65 V @ 6 mA, referenced to
–Vin), the module is turned off. When GATE IN is floating
(open collector), the module is turned on. The open circuit
voltage of the GATE IN pin is less than 10 V. This applies
to VI-/ MI-200, VI-/ MI-J00 and MegaMod / MI-MegaMod
Family modules.
Output Voltage Programming. (Figure 7–2) Consult
Vicor’s Applications Engineering Department before
attempting large signal applications at high repetition
rates due to ripple current considerations with the internal
output capacitors. This applies to VI-/ MI-200, VI-/ MI-J00,
ComPAC / MI-ComPAC, FlatPAC and MegaMod /
MI-MegaMod Family modules.
Vout =
+
–
6
GATE
IN
5
1µF
TLP798G
Agilent 6N139
GATE
OUT
–IN
+IN
+OUT
+S
TRIM
–S
Zero Current
Switching
Converter
Driver
+IN
GATE
IN
GATE
OUT
–IN
+S
Load
TRIM
–S
–OUT
Figure 7–3 — Negative inputs (with positive ground)
+S
TRIM
–S
+IN
+
–
Load
+
–
VI-200 and VI-J00 Family Design Guide
GATE
IN
GATE
OUT
–IN
–OUT
Figure 7–2 — Output voltage programming
Page 12 of 98
Zero Current
Switching
Converter
Driver
GATE
OUT
–IN
–OUT
+OUT
Zero Current
Switching
Converter
Driver
+OUT
GATE
IN
+
–
Load
Figure 7–1 — Logic disable
+
–
Remote Sensing. (Figure 7–4) Output voltage between
+OUT and –OUT must be maintained below 110% of
nominal. Do not exceed 0.25 V drop in negative return as
the current limit setpoint is moved out proportionately.
The sense should be closed at the module if remote
sensing is not desired. Applies to VI-/ MI-200, VI-/ MI-J00,
ComPAC / MI-ComPAC, FlatPAC and MegaMod /
MI-MegaMod Family modules. Excessively long sense leads
and / or excessive external capacitance at the load may
result in module instability. Please consult Vicor
Applications Engineering for compensation methods.
Vtrim x Vnom
2.5
+IN
1
2
Negative Inputs (with positive ground). (Figure 7–3)
Vicor modules have isolated inputs and outputs making
negative input configurations easy. Fusing should always
be placed in the positive lead.
Zero Current
Switching
Converter
Driver
Figure 7–4 — Remote sensing
Rev 3.5
Apps. Eng. 800 927.9474
vicorpower.com
800 735.6200
+OUT
•••
+S
TRIM
–S
•••
•••
–OUT
•••
Load
7. Application Circuits / Converter Array Design Considerations
Design Guide & Applications Manual
For VI-200 and VI-J00 Family DC-DC Converters and Configurable Power Supplies
Parallel Boost. (Figure 7–5) U.S. Patent #4,648,020 —
other patents pending. To retain accurate power sharing
between a Driver and (n) number of Boosters, provide
adequate input and output power bussing. This applies to
VI-/ MI-200 and MegaMod / MI-MegaMod Family
modules. See Module Do’s and Don’ts for recommended
external components. (Section 3)
Programmable Current Source. (Figure 7–6) Module
output voltage should not exceed the rated voltage of the
operational amplifier. This applies to VI-/ MI-200,
VI-/ MI-J00, ComPAC / MI-ComPAC, FlatPAC and
MegaMod / MI-MegaMod Family modules.
+IN
GATE
IN
GATE
OUT
–IN
Zero Current
Switching
Converter
#1
Driver
VI-2xx-xx
NOTE: When using a VI-J00 module, the TRIM pin
voltage should be clamped to 2.75 V to avoid
damage to the module. This corresponds to the
maximum trim up voltage. This circuit or functional
equivalent must be used when charging batteries.
Do not exceed the nominal current ratings of the
converter. Example,
Pout
Vnominal
Dual Output Voltages. (Figure 7–7) Vicor modules have
isolated outputs so they can easily be referenced to a
common node creating positive and / or negative rails.
+IN
+OUT
+
–
+S
TRIM
–S
GATE
IN
GATE
OUT
–IN
–OUT
+
–
+OUT
Zero Current
Switching
Converter
Driver
Load requiring
positive output
–OUT
Load
+IN
GATE
IN
GATE
OUT
–IN
+OUT
Zero Current
Switching
Converter
#n
Booster
+S
TRIM
–S
VI-Bxx-xx
–OUT
+IN
+
–
GATE
IN
GATE
OUT
+OUT
Zero Current
Switching
Converter
Driver
–IN
Figure 7–5 — Parallel boost. U.S. Patent #4,648,020 — other
patents pending.
Figure 7–7 — Dual output voltages
I
+IN
+
–
+S
TRIM
–S
GATE
IN
GATE
OUT
–IN
+OUT
Zero Current
Switching
Converter
Driver
+S
TRIM
-S
1K
10 µF
–OUT
–
OP
AMP
+
0.01
1K
Load
1K 1K
0.05 Ω
V Control
0.1 V/A
Figure 7–6 — Programmable current source
VI-200 and VI-J00 Family Design Guide
Page 13 of 98
Rev 3.5
Apps. Eng. 800 927.9474
vicorpower.com
800 735.6200
+S
TRIM
–S
–OUT
Load requiring
negative output