V048F030T070 Datasheet, PDF (10/11 Pages) Vicor Corporation – VTM Current Multiplier

Application Note (continued)
V•I Chip Voltage Transformation Module
V•I Chip VTM Level 2 Transient Behavioral Model for 48 V to 3 V, 70 A
L IN = 5 nH
IOUT
0.12 nH
ROUT
LOUT = 1.1 nH
+
R_{1R.C3CINmINΩ}
V•I
1.7 mΩ
+
0.6 mΩ
RR_COOUUTT
0.085 mΩ
CIN
4 µF
1/16 • Iout
+
+ ^{1/16 • Vin}
VIN
IQ
63 mA
––
COUT
254 µF
VOUT
K
–
–
©
Figure 17 — This model characterizes the AC operation of the V•I Chip VTM 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.
In figures below;
K = VTM transformation ratio
R_O = VTM output resistance
FPA Adaptive Loop
V_f = PRM output (Factorized Bus Voltage)
V_O = VTM output
V_L = Desired load voltage
Vo = VL ^± 1.0%
VC
VH
PC
SC
+Out
Vin
TM
SG
IL
OS
NC
NC
PR _PRM-AL CD
+In
+Out
ROS
RCD
Factorized
Bus (Vf)
Vf =
VL
K
+
(Io•Ro)
K
+In
L
-Out
TM
VC
VTM
O
PC
+Out
A
K
D
–In
–Out
Ro -In
-Out
Figure 18 — The PRM controls the factorized bus voltage, V_f, in proportion to output current to compensate for the output resistance, Ro, of the VTM. The VTM
output voltage is typically within 1% of the desired load voltage (V_L) over all line and load conditions.
FPA Non-isolated Remote Loop
Vin
VC
VH
PC
SC
TM
SG
IL
OS
NC
NC
PR _PRM-AL CD
+In
+Out
–In
–Out
Remote
Loop
Control
Factorized
Power Bus
V_f = f (Vs)
+Out
+In
-Out
TM
VC
VTM
PC
+Out
K
Ro ^-In
-Out
Vo = VL ^± 0.4%
+S _L
O
A
–S D
Figure 19 — An external error amplifier or Point-of-Load IC (POLIC) senses the load voltage and controls the PRM output – the Factorized Bus – as a function of
output current, compensating for the output resistance of the VTM and for distribution resistance.
vicorpower.com 800-735-6200
V•I Chip Voltage Transformation Module
V048F030T070
Rev. 2.7
Page 10 of 11