VICOR VTM48EF015T115A00

VTM48EF015T115A00
VTM
Transformer
TM
S
®
C
FEATURES
• 48 Vdc to 1.5 Vdc 115 A transformer
- Operating from standard 48 V or 24 V PRMTM regulators
• High efficiency (>94%) reduces system power
consumption
• High density (392 A/in3)
• “Full Chip” V• I Chip package enables surface mount,
low impedance interconnect to system board
• Contains built-in protection features:
-
Overvoltage Lockout
Overcurrent
Short Circuit
Overtemperature
• Provides enable / disable control,
internal temperature monitoring
• ZVS / ZCS resonant Sine Amplitude Converter topology
• Less than 50ºC temperature rise at full load
in typical applications
TYPICAL APPLICATIONS
• High End Computing Systems
• Automated Test Equipment
• High Density Power Supplies
• Communications Systems
US
C
NRTL
US
DESCRIPTION
The V• I ChipTM transformer is a high efficiency (>94%) Sine
Amplitude ConverterTM (SACTM) operating from a 26 to 55 Vdc
primary bus to deliver an isolated output. The Sine Amplitude
Converter offers a low AC impedance beyond the bandwidth
of most downstream regulators; therefore capacitance normally
at the load can be located at the input to the Sine Amplitude
Converter. Since the K factor of the VTM48EF015T115A00 is
1/32, the capacitance value can be reduced by a factor of 1024,
resulting in savings of board area, materials and total system cost.
The VTM48EF015T115A00 is provided in a V• I Chip package
compatible with standard pick-and-place and surface mount
assembly processes. The co-molded V•I Chip package provides
enhanced thermal management due to a large thermal
interface area and superior thermal conductivity. The high
conversion efficiency of the VTM48EF015T115A00 increases
overall system efficiency and lowers operating costs compared
to conventional approaches.
The VTM48EF015T115A00 enables the utilization of Factorized
Power ArchitectureTM which provides efficiency and size
benefits by lowering conversion and distribution losses and
promoting high density point of load conversion.
VIN = 26 to 55 V
IOUT = 115 A (NOM)
VOUT = 0.8 to 1.7 V (NO LOAD)
K= 1/32
PART NUMBER
DESCRIPTION
VTM48EF015T115A00
-40°C to 125°C TJ
TYPICAL APPLICATION
Voltage
Control
Feedback
Enable/
Disable
Voltage
Reference
PC
PR
+IN
TM
+OUT
PC
-IN
IF RE
+OUT1
+OUT2
+IN
PRMTM
Regulator
38 to 55
Vdc Input
VTM48EF015T115A00
Load
-IN
-OUT
SG VC
VC
Current
Sense
-OUT1
-OUT2
PC
+OUT1
+OUT2
+IN
VTM48EF015T115A00
Constant
Vc
-IN
VC
-OUT1
-OUT2
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 1 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00 PRELIMINARY DATASHEET
1.0 ABSOLUTE MAXIMUM VOLTAGE RATINGS
The absolute maximum ratings below are stress ratings only. Operation at or beyond these maximum ratings can cause permanent
MIN
MAX
UNIT
MIN
MAX
UNIT
damage to the device.
+ IN to - IN . . . . . . . . . . . . . . . . . . . . . . . . . . .
PC to - IN . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TM to -IN . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VC to - IN . . . . . . . . . . . . . . . . . . . . . . . . . . . .
-1.0
-0.3
-0.3
-0.3
60
20
7
20
VDC
VDC
VDC
VDC
IM to - IN.........................................................
+ IN / - IN to + OUT / - OUT (hipot)................
+ IN / - IN to + OUT / - OUT (working)...........
+ OUT to - OUT...............................................
0
3.15
100
60
5.5
-1.0
VDC
VDC
VDC
VDC
2.0 ELECTRICAL CHARACTERISTICS
Specifications apply over all line and load conditions unless otherwise noted; Boldface specifications apply over the temperature
range of -40°C < TJ < 125°C (T-Grade); All other specifications are at TJ = 25ºC unless otherwise noted.
ATTRIBUTE
SYMBOL
Input voltage range
VIN
VIN slew rate
CONDITIONS / NOTES
No external VC applied
VC applied
MIN
TYP
26
0
dVIN /dt
VIN UV turn off
VIN_UV
No Load power dissipation
PNL
Inrush current peak
IINRP
DC input current
Transfer ratio
Output voltage
IIN_DC
K
VOUT
Output current (average)
IOUT_AVG
Output current (peak)
Output power (average)
IOUT_PK
POUT_AVG
ηAMB
Efficiency (ambient)
ηHOT
η20%
Efficiency (hot)
Efficiency (over load range)
Output resistance (cold)
Output resistance (ambient)
Output resistance (hot)
ROUT_COLD
ROUT_AMB
ROUT_HOT
Load capacitance
COUT
Switching frequency
Output ripple frequency
FSW
FSW_RP
Output voltage ripple
VOUT_PP
Output inductance (parasitic)
LOUT_PAR
Output capacitance (internal)
COUT_INT
PROTECTION
Overvoltage lockout
Overvoltage lockout
response time constant
Output overcurrent trip
Short circuit protection trip current
Output overcurrent
response time constant
Short circuit protection response time
Thermal shutdown setpoint
Reverse inrush current protection
Module latched shutdown,
No external VC applied, IOUT = 115A
VIN = 48 V
VIN = 26 V to 55 V
VIN = 48 V, TC = 25ºC
VIN = 26 V to 55 V, TC = 25ºC
VC enable, VIN = 48 V, COUT = 64400 µF,
RLOAD = 12 mΩ
K = VOUT / VIN, IOUT = 0 A
VOUT = VIN • K - IOUT • ROUT, Section 10
30°C < Tc < 100°C,
Iout_max = - (3/14) * Tc + 136.43
TC = 30ºC
TPEAK < 10 ms, IOUT_AVG ≤ 115 A
IOUT_AVG ≤ 115 A
VIN = 48 V, IOUT = 115 A
VIN = 26 V to 55 V, IOUT = 115 A
VIN = 48 V, IOUT = 57.5 A
VIN = 48 V, IOUT = 130
A
VIN = 48 V, TC = 100°C, IOUT = 115 A
23 A < IOUT < 115 A
TC = -40°C, IOUT = 115 A
TC = 25°C, IOUT = 115 A
TC = 100°C, IOUT = 115 A
VTM Standalone Operation.
VIN pre-applied, VC enable
18
1.5
2.2
7.2
COUT = 0 F, IOUT = 115 A, VIN = 48 V,
20 MHz BW, Section 11
Frequency up to 30 MHz,
Simulated J-lead model
Effective Value at 1.5 VOUT
Module latched shutdown
TOVLO
Effective internal RC filter
IOCP
ISCP
55.1
Effective internal RC filter (Integrative).
TSCP
From detection to cessation
of switching (Instantaneous)
TJ_OTP
26
V
5.8
6.5
4.2
5.5
W
11
A
4.5
A
V/V
V
125
VDC
A
130
200
185
A
W
1.0
1.08
1.18
%
%
mΩ
mΩ
mΩ
64400
µF
1.40
2.80
1.50
3.00
MHz
MHz
150
200
mV
91.7
94.0
90.9
90.7
0.67
0.84
1.00
150
pH
420
µF
58.2
60
0.2
138
250
TOCP
V/µs
115
90.0
84.0
91.5
89.5
89.0
80
0.35
0.50
0.64
UNIT
55
55
1
1/32
1.30
2.60
VIN_OVLO+
MAX
190
V
µs
250
A
A
9.1
ms
1
µs
130
135
ºC
Reverse Inrush protection enabled for this product
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 2 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00
3.0 SIGNAL CHARACTERISTICS
Specifications apply over all line and load conditions unless otherwise noted; Boldface specifications apply over the temperature
range of -40°C < TJ < 125°C (T-Grade); All other specifications are at TJ = 25°C unless otherwise noted.
• Used to wake up powertrain circuit.
• A minimum of 11.5 V must be applied indefinitely for VIN < 26 V
to ensure normal operation.
• VC slew rate must be within range for a succesful start.
SIGNAL TYPE
STATE
ATTRIBUTE
External VC voltage
VTM CONTROL : VC
• PRM VC can be used as valid wake-up signal source.
• Internal Resistance used in “Adaptive Loop” compensation
• VC voltage may be continuously applied
SYMBOL
VVC_EXT
VC current draw
IVC
Steady
ANALOG
INPUT
VC internal diode rating
VC internal resistor
VC internal resistor
temperature coefficient
VC start up pulse
VC slew rate
VC inrush current
CONDITIONS / NOTES
Required for start up, and operation
below 26 V. See Section 7.
VC = 11.5 V, VIN = 0 V
VC = 11.5 V, VIN > 26 V
VC = 16.5 V, VIN > 26 V
Fault mode. VC > 11.5 V
MIN
TYP
11.5
16.5
115
0
0
60
100
N/A
DVC_INT
RVC-INT
MAX UNIT
TVC_COEFF
150
mA
V
kΩ
N/A ppm/°C
Tpeak <18 ms
20
Required for proper start up;
0.02
0.25
VC = 16.5 V, dVC/dt = 0.25 V/µs
1
V
pre-applied,
PC
floating,
IN
VC to VOUT turn-on delay
TON
500
VC enable, CPC = 0 µF
Transitional
VC = 11.5 V to PC high, VIN = 0 V,
VC to PC delay
Tvc_pc
75
125
dVC/dt = 0.25 V/µs
VC = 0 V
3.2
Internal VC capacitance
CVC_INT
PRIMARY CONTROL : PC
• The PC pin enables and disables the VTM.
• Module will shutdown when pulled low with an impedance
When held below 2 V, the VTM will be disabled.
less than 400 Ω.
• PC pin outputs 5 V during normal operation. PC pin is equal to 2.5 V
• In an array of VTMs, connect PC pin to synchronize start up.
during fault mode given VIN > 26 V or VC > 11.5 V.
• PC pin cannot sink current and will not disable other modules
• After successful start up and under no fault condition, PC can be used as
during fault mode.
a 5 V regulated voltage source with a 2 mA maximum current.
Start Up
SIGNAL TYPE
STATE
Steady
ANALOG
OUTPUT
Start Up
Enable
Disable
DIGITAL
INPUT / OUPUT
Transitional
ATTRIBUTE
PC voltage
PC source current
PC resistance (internal)
PC source current
PC capacitance (internal)
PC resistance (external)
PC voltage
PC voltage (disable)
PC pull down current
PC disable time
PC fault response time
VVC_SP
dVC/dt
IINR_VC
SYMBOL
SIGNAL TYPE
ANALOG
OUTPUT
STATE
Steady
ATTRIBUTE
IM Voltage (No Load)
IM Voltage (50%)
IM Voltage (Full Load)
IM Gain
IM Resistance (External)
CONDITIONS / NOTES
MIN
TYP
4.7
5
50
50
150
100
60
2
2.5
VPC
IPC_OP
RPC_INT
Internal pull down resistor
IPC_EN
CPC_INT
Section 7
RPC_S
VPC_EN
VPC_DIS
IPC_PD
TPC_DIS_T
TFR_PC
From fault to PC = 2 V
CURRENT MONITOR : IM
• The IM pin voltage varies between 0.2 V and 0.61 V representing the
output current within ±25% under all operating line temperature
conditions between 50% and 100%.
SYMBOL
VIM_NL
VIM_50%
VIM_FL
A IM
RIM_EXT
V
V
V/µs
A
µs
µs
µF
MAX UNIT
5.3
2
400
300
1000
3
2
5.1
5
100
V
mA
kΩ
µA
pF
kΩ
V
V
mA
µs
µs
• The IM pin provides a DC analog voltage proportional to
the output current of the VTM.
CONDITIONS / NOTES
MIN
TYP
MAX
UNIT
0.2
0.07
0.28
0.61
6
0.3
V
V
V
mV/A
MΩ
TJ = 25ºC, VIN = 48 V, IOUT = 0 A
TJ = 25ºC, VIN = 48 V, IOUT = 57.5 A
TJ = 25ºC, VIN = 48 V, IOUT = 115 A
TJ = 25ºC, VIN = 48 V, IOUT > 57.5 A
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
2.5
Rev. 3.4
12/2010
Page 3 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00 PRELIMINARY DATASHEET
TEMPERATURE MONITOR : TM
• The TM pin monitors the internal temperature of the VTM controller IC
• The TM pin has a room temperature setpoint of 3 V
within an accuracy of ±5°C.
and approximate gain of 10 mV/°C.
• Can be used as a "Power Good" flag to verify that the VTM is operating.
• Output drives Temperature Shutdown comparator
SIGNAL TYPE
STATE
ANALOG
OUTPUT
ATTRIBUTE
TM voltage
TM source current
TM gain
Steady
Disable
DIGITAL OUTPUT
(FAULT FLAG)
Transitional
SYMBOL
VTM_AMB
ITM
ATM
TM voltage ripple
VTM_PP
TM voltage
TM resistance (internal)
TM capacitance (external)
TM fault response time
VTM_DIS
RTM_INT
CTM_EXT
TFR_TM
CONDITIONS / NOTES
TJ controller = 27°C
MIN
TYP
MAX UNIT
2.95
3.00
3.05
100
V
µA
mV/°C
200
mV
50
50
V
kΩ
pF
µs
10
CTM = 0 F, VIN = 48 V,
IOUT = 115 A
120
Internal pull down resistor
25
From fault to TM = 1.5 V
0
40
10
4.0 TIMING DIAGRAM
IOUT
6
7
ISSP
IOCP
1
2 3
VC
4
8
d
5
b
VVC-EXT
a
VOVLO
VIN
NL
≥ 26 V
c
e
f
VOUT
TM
VTM-AMB
PC
g
5V
3V
a: VC slew rate (dVC/dt)
b: Minimum VC pulse rate
c: TOVLO
d: TOCP
e: Output turn on delay (TON)
f: PC disable time (TPC-DIS)
g: VC to PC delay (TVC-PC)
1. Initiated VC pulse
2. Controller start
3. VIN ramp up
4. VIN = VOVLO
5. VIN ramp down no VC pulse
6. Overcurrent
7. Start up on short circuit
8. PC driven low
Notes:
– Timing and voltage is not to scale
– Error pulse width is load dependent
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 4 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00
5.0 APPLICATION CHARACTERISTICS
The following values, typical of an application environment, are collected at TC = 25ºC unless otherwise noted. See associated figures
for general trend data.
ATTRIBUTE
SYMBOL
No load power dissipation
Efficiency (ambient)
Efficiency (hot)
Output resistance (cold)
Output resistance (ambient)
Output resistance (hot)
PNL
ηAMB
ηHOT
ROUT_COLD
ROUT_AMB
ROUT_HOT
Output voltage ripple
VOUT_PP
VOUT transient (positive)
VOUT_TRAN+
VOUT transient (negative)
VOUT_TRAN-
CONDITIONS / NOTES
TYP
UNIT
VIN = 48 V, PC enabled
VIN = 48 V, IOUT = 115 A
VIN = 48 V, IOUT = 115 A, TC = 100ºC
VIN = 48 V, IOUT = 115 A, TC = -40ºC
VIN = 48 V, IOUT = 115 A
VIN = 48 V, IOUT = 115 A, TC = 100ºC
COUT = 0 F, IOUT = 115 A, VIN = 48 V,
20 MHz BW, Section 12
IOUT_STEP = 0 A TO 115A, VIN = 48 V,
ISLEW = 36 A /us
IOUT_STEP = 115 A to 0 A, VIN = 48 V
ISLEW = 23 A /us
2.1
91.8
90.3
0.7
0.9
1.0
W
%
%
mΩ
mΩ
mΩ
116
mV
40
mV
60
mV
Full Load Efficiency vs. TCASE
No Load Power Dissipation vs. Line Voltage
94
Full Load Efficiency (%)
3.5
3.0
2.5
2.0
1.5
92
90
88
86
84
82
80
1.0
26
29
32
35
38
41
43
46
49
52
-40
55
-20
TCASE:
-40°C
25°C
VIN :
100°C
Efficiency & Power Dissipation -40°C Case
84
PD
76
72
26
39
52
65
78
91
26 V
26 V
48 V
55 V
48 V
100
55 V
104
117
48
44
40
36
32
28
24
20
16
12
8
4
0
η
88
84
80
PD
76
72
130
0
13
26
39
Load Current (A)
VIN:
80
92
Efficiency (%)
88
13
60
96
Power Dissipation (W)
Efficiency (%)
η
0
40
Efficiency & Power Dissipation 25°C Case
48
44
40
36
32
28
24
20
16
12
8
4
0
96
80
20
Figure 2 – Full load efficiency vs. temperature
Figure 1 – No load power dissipation vs. VIN
92
0
Case Temperature (°C)
Input Voltage (V)
52
65
78
91
104
117
Power Dissipation (W)
Power Dissipation (W)
4.0
130
Load Current (A)
26 V
Figure 3 – Efficiency and power dissipation at –40°C
48 V
55 V
VIN:
26 V
48 V
55 V
26 V
48 V
55 V
Figure 4 – Efficiency and power dissipation at 25°C
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 5 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00 PRELIMINARY DATASHEET
Efficiency & Power Dissipation 100°C Case
88
84
PD
76
72
0
12
23
35
26 V
VIN:
46 58 69 81
Load Current (A)
48 V
55 V
92
2.0
1.5
ROUT (mΩ)
Efficiency (%)
92
80
ROUT vs. TCASE at VIN = 48 V
48
44
40
36
32
28
24
20
16
12
8
4
0
Power Dissipation (W)
96
1.0
0.5
0.0
-40
104 115
-20
0
26 V
48 V
55 V
I OUT :
Output Voltage Ripple vs. Load
150
Output Current (A)
VRIPPLE (mV PK-PK)
175
125
100
75
50
25
0
23
35
46
58
69
81
92
104
Load Current (A)
VIN:
26 V
48 V
60
80
100
115 A
57.5 A
Safe Operating Area
200
12
40
Figure 6 – ROUT vs. temperature
Figure 5 – Efficiency and power dissipation at 100°C
0
20
Case Temperature (ºC)
115
220
200
180
160
140
120
100
80
60
40
20
0
Limited by Power
< 10 ms, 200 A Maximum Current
< 30°C TCASE, 130 A Maximum Current
Limited by ROUT
115 A Maximum Current Region
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
Output Voltage (V)
55 V
Figure 7 – VRIPPLE vs. IOUT ; No external COUT.
Board mounted module, scope setting : 20 MHz analog BW
Figure 8 – Safe operating area
Figure 9 – Full load ripple, 100 µF CIN; No external COUT.
Board mounted module, scope setting : 20 MHz analog BW
Figure 10 –Start up from application of VIN; VC pre-applied
COUT = 64400 µF
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 6 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00
Figure 11 – Start up from application of VC; VIN pre-applied
COUT = 64400 µF
Figure 12 – 0 A– 115 A transient response:
CIN = 100 µF, no external COUT
IM Voltage vs. Load at VIN = 48 V
0.6
0.5
IM (V)
0.4
0.3
0.2
0.1
0
12
23
35
46
58
69
81
92
104
115
Load Current (A)
TCASE :
Figure 13 – 115 A – 0 A transient response:
CIN = 100 µF, no external COUT
-40°C
25°C
100°C
Figure 14 – IM voltage vs. load
IM Voltage vs. Load at 25°C Case
0.6
0.6
IM Voltage at 115 A Load vs. TCASE
0.5
0.5
IM (V)
IM (V)
0.4
0.3
0.4
0.2
0.3
0.1
0.0
0.2
12
23
35
46
58
69
81
92
104
115
-40
-20
Load Current (A)
VIN :
26 V
Figure 15 – IM voltage vs. load
48 V
0
20
40
60
80
100
TCASE (°C)
55 V
VIN :
26 V
48 V
55 V
Figure 16 – Full load IM voltage vs. TCASE
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 7 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00 PRELIMINARY DATASHEET
6.0 GENERAL CHARACTERISTICS
Specifications apply over all line and load conditions unless otherwise noted; Boldface specifications apply over the temperature
range of -40ºC < TJ < 125ºC (T-Grade); All Other specifications are at TJ = 25°C unless otherwise noted.
ATTRIBUTE
SYMBOL
MECHANICAL
Length
Width
Height
Volume
Weight
L
W
H
Vol
W
CONDITIONS / NOTES
32.25 / [1.270]
21.75 / [0.856]
6.48 / [0.255]
No heat sink
Nickel
Palladium
Gold
Lead finish
MIN
TYP
32.5 / [1.280]
22.0 / [0.866]
6.73 / [0.265]
4.81 / [0.294]
14.5 / [0.512]
MAX
UNIT
32.75 / [1.289]
22.25 / [0.876]
6.98 / [0.275]
mm/[in]
mm/[in]
mm/[in]
cm3/[in3]
g/[oz]
0.51
0.02
0.003
2.03
0.15
0.051
µm
-40
N/A
125
N/A
°C
°C
THERMAL
Operating temperature
TJ
φJC
Thermal resistance
VTM48EF015T115A00 (T-Grade)
VTM48EF015M115A00 (M-Grade)
Isothermal heatsink and
isothermal internal PCB
Thermal capacity
ASSEMBLY
Peak compressive force
applied to case (Z-axis)
1
°C/W
9
Ws/°C
6
5.41
125
N/A
Supported by J-lead only
Storage temperature
TST
Moisture sensitivity level
MSL
ESDHBM
ESD withstand
ESDCDM
VTM48EF015T115A00 (T-Grade)
VTM48EF015M115A00 (M-Grade)
MSL 6, TOB = 4 hrs
MSL 5
Human Body Model,
"JEDEC JESD 22-A114C.01"
Charge Device Model,
"JEDEC JESD 22-C101-C"
-40
N/A
lbs
lbs / in2
°C
°C
TBD
VDC
TBD
SOLDERING
MSL 6, TOB = 4 hrs
MSL 5
Peak temperature during reflow
Peak time above 245°C
Peak heating rate during reflow
Peak cooling rate post reflow
SAFETY
Working voltage (IN – OUT)
Isolation voltage (hipot)
Isolation capacitance
Isolation resistance
60
1.5
1.5
VIN_OUT
VHIPOT
CIN_OUT
RIN_OUT
MTBF
Agency approvals / standards
Unpowered unit
MIL-HDBK-217 Plus Parts Count;
25ºC Ground Benign, Stationary,
Indoors / Computer Profile
Telcordia Issue 2 - Method I Case 1;
Ground Benign, Controlled
cTUVus
cURus
CE Mark
RoHS 6 of 6
100
1800
10
2000
245
225
90
3
6
°C
°C
s
°C/s
°C/s
60
VDC
VDC
pF
MΩ
2200
TBD
MHrs
TBD
MHrs
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 8 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00
7.0 USING THE CONTROL SIGNALS VC, PC, TM, IM
The VTM Control (VC) pin is an input pin which powers the
internal VCC circuitry when within the specified voltage range
of 11.5 V to 16.5 V. This voltage is required for VTMTM
transformer start up and must be applied as long as the input
is below 26 V. In order to ensure a proper start, the slew rate of
the applied voltage must be within the specified range.
Some additional notes on the using the VC pin:
• In most applications, the VTM module will be powered by an
upstream PRMTM regulator which provides a 10 ms
VC pulse during start up. In these applications the VC pins
of the PRM and VTM should be tied together.
• The VC voltage can be applied indefinitely allowing for
continuous operation down to 0 VIN.
• The fault response of the VTM module is latching.
A positive edge on VC is required in order to restart the unit.
If VC is continuously applied the PC pin may be toggled to
restart the VTM module.
Primary Control (PC) pin can be used to accomplish the
following functions:
• Delayed start: Upon the application of VC, the PC pin will
source a constant 100 µA current to the internal RC
network. Adding an external capacitor will allow further
delay in reaching the 2.5 V threshold for module start.
• Auxiliary voltage source: Once enabled in regular
operational conditions (no fault), each VTM PC provides a
regulated 5 V, 2 mA voltage source.
• Output disable: PC pin can be actively pulled down in order
to disable the module. Pull down impedance shall be lower
than 400 Ω.
• Fault detection flag: The PC 5 V voltage source is internally
turned off as soon as a fault is detected. It is important to
notice that PC doesn’t have current sink capability. Therefore,
in an array, PC line will not be capable of disabling
neighboring modules if a fault is detected.
• Fault reset: PC may be toggled to restart the unit if VC
is continuously applied.
Temperature Monitor (TM) pin provides a voltage
proportional to the absolute temperature of the converter
control IC.
It can be used to accomplish the following functions:
• Monitor the control IC temperature: The temperature in
Kelvin is equal to the voltage on the TM pin scaled
by 100. (i.e. 3.0 V = 300 K = 27ºC). If a heat sink is applied,
TM can be used to thermally protect the system.
• Fault detection flag: The TM voltage source is internally
turned off as soon as a fault is detected. For system
monitoring purposes (microcontroller interface) faults are
detected on falling edges of TM signal.
Current Monitor (IM) pin provides a voltage proportional to
the output current of the VTM module. The nominal voltage
will vary between 0.07 V and 0.61 V over the output current
range of the VTM module (See Figures 11–13). The accuracy of
the IM pin will be within 25% under all line and temperature
conditions between 50% and 100% load.
8.0 START UP BEHAVIOR
Depending on the sequencing of the VC with respect to the
input voltage, the behavior during start up will vary as follows:
• Normal operation (VC applied prior to VIN): In this case the
controller is active prior to ramping the input. When the
input voltage is applied, the VTM module output voltage
will track the input (See Figure 10). The inrush current is
determined by the input voltage rate of rise and output
capacitance. If the VC voltage is removed prior to the input
reaching 26 V, the VTM may shut down.
• Stand-alone operation (VC applied after VIN): In this case the
VTM module output will begin to rise upon the application
of the VC voltage (See Figure 11). The Adaptive Soft Start
Circuit (See Section 11) may vary the ouput rate of rise in
order to limit the inrush current to its maximum level. When
starting into high capacitance, or a short, the output current
will be limited for a maximum of 120 µ/sec. After this period,
the Adaptive Soft Start Circuit will time out and the VTM
module may shut down. No restart will be attempted until
VC is re-applied or PC is toggled. The maximum output
capacitance is limited to 64400 µF in this mode of operation
to ensure a sucessful start.
9.0 THERMAL CONSIDERATIONS
V• I Chip™ products are multi-chip modules whose
temperature distribution varies greatly for each part number as
well as with the input / output conditions, thermal
management and environmental conditions. Maintaining the
top of the VTM48EF015T115A00 case to less than 100ºC will
keep all junctions within the V• I Chip module below 125ºC for
most applications.
The percent of total heat dissipated through the top surface
versus through the J-lead is entirely dependent on the
particular mechanical and thermal environment. The heat
dissipated through the top surface is typically 60%. The heat
dissipated through the J-lead onto the PCB board surface is
typically 40%. Use 100% top surface dissipation when
designing for a conservative cooling solution.
It is not recommended to use a V• I Chip module for an extended
period of time at full load without proper heat sinking.
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 9 of 17
v i c o r p o w e r. c o m
v i c o r p o w e r. c o m
PC
-V IN
C IN
1000 pF
2.5 V
D VC_INT
PC Pull-Up
& Source
R VC_INT
VC
+V IN
100 A
18 V
10.5 V
5V
2 mA
2.5 V
Enable
150 K
V DD
Regulator
Supply
Enable
OVLO
UVLO
V IN
Adaptive
Soft Start
Enable
Modulator
Enable
Fault Logic
Gate Drive
Supply
Primary
Gate
Drive
Slow Current
Limit
V REF
(127°C)
Overtemperature
Protection
Fast Current
Limit
Over Current Protection
V REF
Lr
Primary Stage &
Resonant Tank
Cr
Single Ended
Primary
Current Sensing
Q2
Q1
Secondary
Gate Drive
Power
Transformer
Temperature
Dependent
Voltage Source
V REF
C2
C1
Q3
40 K
1K
Q4
0.01
3 V MAX
240 A MAX
Synchronous
Rectification
F
TM
IM
Right
J-lead
-V OUT
C OUT
+V OUT
+V OUT
C OUT
-V OUT
Left
J-lead
VTM48EF015T115A00 PRELIMINARY DATASHEET
10.0 VTM48EF015T115A00 BLOCK DIAGRAM
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 10 of 17
VTM48EF015T115A00
11.0 SINE AMPLITUDE CONVERTERTM POINT OF LOAD CONVERSION
The Sine Amplitude Converter (SACTM) uses a high frequency
resonant tank to move energy from input to output. (The
resonant tank is formed by Cr and leakage inductance Lr in the
power transformer windings as shown in the VTMTM module
Block Diagram. See Section 10). The resonant LC tank,
operated at high frequency, is amplitude modulated as a
function of input voltage and output current. A small amount
of capacitance embedded in the input and output stages of
the module is sufficient for full functionality and is key to
achieving power density.
The VTM48EF015T115A00 SAC can be simplified into the
following model:
90 pH
OUT
IIOUT
LLININ==3.7
nH
5 nH
ROUT
R
OUT
+
0.84 mΩ
R
RCIN
CIN
6.3 mΩ
VININ
V
LOUT = 150 pH
CCININ
V• I
1/32 • IOUT
+
+
–
900 nF
IIQQ
46 mA
RCOUT
R
COUT
0.98 Ω
+
50 µΩ
1/32 • VIN
CCOUT
OUT
420 µF
VOUT
V
OUT
–
K
–
–
Figure 17 – V•I ChipTM AC model
At no load:
VOUT = VIN • K
(1)
interesting attributes. Assuming that ROUT = 0 Ω and IQ = 0 A,
Eq. (3) now becomes Eq. (1) and is essentially load
independent, resistor R is now placed in series with VIN as
shown in Figure 18.
K represents the “turns ratio” of the SAC.
Rearranging Eq (1):
K=
VOUT
VIN
R
(2)
VVin
IN
+
–
SAC
SAC
= 1/32
1/32
KK =
Vout
V
OUT
In the presence of load, VOUT is represented by:
VOUT = VIN • K – IOUT • ROUT
(3)
and IOUT is represented by:
IOUT =
IIN – IQ
K
Figure 18 – K = 1/32 Sine Amplitude Converter with series
input resistor
The relationship between VIN and VOUT becomes:
(4)
ROUT represents the impedance of the SAC, and is a function of
the RDSON of the input and output MOSFETs and the winding
resistance of the power transformer. IQ represents the
quiescent current of the SAC control and gate drive circuitry.
The use of DC voltage transformation provides additional
VOUT = (VIN – IIN • R) • K
(5)
Substituting the simplified version of Eq. (4)
(IQ is assumed = 0 A) into Eq. (5) yields:
VOUT = VIN • K – IOUT • R • K2
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
(6)
Rev. 3.4
12/2010
Page 11 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00 PRELIMINARY DATASHEET
This is similar in form to Eq. (3), where ROUT is used to
represent the characteristic impedance of the SACTM. However,
in this case a real R on the input side of the SAC is effectively
scaled by K2 with respect to the output.
Assuming that R = 1 Ω, the effective R as seen from the secondary
side is 0.98 mΩ, with K = 1/32 as shown in Figure 18.
A similar exercise should be performed with the addition of a
capacitor or shunt impedance at the input to the SAC. A
switch in series with VIN is added to the circuit. This is depicted
in Figure 19.
S
VVin
IN
+
–
C
SAC
SAC
K = 1/32
K = 1/32
VVout
OUT
Figure 19 – Sine Amplitude ConverterTM with input capacitor
A change in VIN with the switch closed would result in a
change in capacitor current according to the following
equation:
IC(t) = C
dVIN
dt
Low impedance is a key requirement for powering a highcurrent, low voltage load efficiently. A switching regulation
stage should have minimal impedance while simultaneously
providing appropriate filtering for any switched current. The
use of a SAC between the regulation stage and the point of
load provides a dual benefit of scaling down series impedance
leading back to the source and scaling up shunt capacitance or
energy storage as a function of its K factor squared. However,
the benefits are not useful if the series impedance of the SAC
is too high. The impedance of the SAC must be low, i.e. well
beyond the crossover frequency of the system.
A solution for keeping the impedance of the SAC low involves
switching at a high frequency. This enables small magnetic
components because magnetizing currents remain low. Small
magnetics mean small path lengths for turns. Use of low loss
core material at high frequencies also reduces core losses.
The two main terms of power loss in the VTMTM module are:
- No load power dissipation (PNL): defined as the power
used to power up the module with an enabled powertrain
at no load.
- Resistive loss (ROUT): refers to the power loss across
the VTMTM transformer modeled as pure resistive
impedance.
PDISSIPATED = PNL + PROUT
(7)
(10)
Therefore,
POUT = PIN – PDISSIPATED = PIN – PNL – PROUT
Assume that with the capacitor charged to VIN, the switch is
opened and the capacitor is discharged through the idealized
SAC. In this case,
IC = IOUT • K
(11)
The above relations can be combined to calculate the overall
module efficiency:
(8)
η =
(9)
=
POUT = PIN – PNL – PROUT
PIN
PIN
(12)
Substituting Eq. (1) and (8) into Eq. (7) reveals:
IOUT =
C
K2
•
dVOUT
dt
The equation in terms of the output has yielded a K2 scaling
factor for C, specified in the denominator of the equation.
A K factor less than unity, results in an effectively larger
capacitance on the output when expressed in terms of the
input. With a K= 1/32 as shown in Figure 19,
C=1 µF would appear as C=1024 µF when viewed
from the output.
VIN • IIN – PNL – (IOUT)2 • ROUT
VIN • IIN
= 1–
(
)
PNL + (IOUT)2 • ROUT
VIN • IIN
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 12 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00
12.0 INPUT AND OUTPUT FILTER DESIGN
A major advantage of a SACTM system versus a conventional
PWM converter is that the former does not require large
functional filters. The resonant LC tank, operated at extreme
high frequency, is amplitude modulated as a function of input
voltage and output current and efficiently transfers charge
through the isolation transformer. A small amount of
capacitance embedded in the input and output stages of the
module is sufficient for full functionality and is key to achieving
high power density.
This paradigm shift requires system design to carefully evaluate
external filters in order to:
1.Guarantee low source impedance.
To take full advantage of the VTMTM transformer dynamic
response, the impedance presented to its input terminals
must be low from DC to approximately 5 MHz. Input
capacitance may be added to improve transient
performance or compensate for high source impedance.
2.Further reduce input and/or output voltage ripple without
sacrificing dynamic response.
Given the wide bandwidth of the VTM module, the source
response is generally the limiting factor in the overall
system response. Anomalies in the response of the source
will appear at the output of the VTM module multiplied by
its K factor.
3.Protect the module from overvoltage transients imposed
by the system that would exceed maximum ratings and
cause failures.
The V•I ChipTM module input/output voltage ranges must
not be exceeded. An internal overvoltage lockout function
prevents operation outside of the normal operating input
range. Even during this condition, the powertrain is
exposed to the applied voltage and power MOSFETs must
withstand it.
13.0 CAPACITIVE FILTERING CONSIDERATIONS
FOR A SINE AMPLITUDE CONVERTERTM
It is important to consider the impact of adding input and
output capacitance to a Sine Amplitude Converter on the
system as a whole. Both the capacitance value and the
effective impedance of the capacitor must be considered.
A Sine Amplitude Converter has a DC ROUT value which has
already been discussed in section 11. The AC ROUT of the
SAC contains several terms:
• Resonant tank impedance
• Input lead inductance and internal capacitance
• Output lead inductance and internal capacitance
The values of these terms are shown in the behavioral model in
section 11. It is important to note on which side of the
transformer these impedances appear and how they reflect
across the transformer given the K factor.
The overall AC impedance varies from model to model. For
most models it is dominated by DC ROUT value from DC to
beyond 500 KHz. The behavioral model in section 11 should be
used to approximate the AC impedance of the specific model.
Any capacitors placed at the output of the VTM reflect back to
the input of the VTM module by the square of the K factor (Eq.
9) with the impedance of the VTM module appearing in series.
It is very important to keep this in mind when using a PRMTM
regulator to power the VTM module. Most PRM modules have
a limit on the maximum amount of capacitance that can be
applied to the output. This capacitance includes both the PRM
output capacitance and the VTM output capacitance reflected
back to the input. In PRM remote sense applications, it is
important to consider the reflected value of VTM output
capacitance when designing and compensating the PRM
control loop.
Capacitance placed at the input of the VTM module appear to
the load reflected by the K factor with the impedance of the
VTM module in series. In step-down ratios, the effective
capacitance is increased by the K factor. The effective ESR of
the capacitor is decreased by the square of the K factor, but
the impedance of the module appears in series. Still, in most
step-down VTM modules an electrolytic capacitor placed at the
input of the module will have a lower effective impedance
compared to an electrolytic capacitor placed at the output. This
is important to consider when placing capacitors at the output
of the module. Even though the capacitor may be placed at
the output, the majority of the AC current will be sourced from
the lower impedance, which in most cases will be the module.
This should be studied carefully in any system design using a
module. In most cases, it should be clear that electrolytic
output capacitors are not necessary to design a stable,
well-bypassed system.
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 13 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00 PRELIMINARY DATASHEET
14.0 CURRENT SHARING
The SACTM topology bases its performance on efficient transfer
of energy through a transformer without the need of closed
loop control. For this reason, the transfer characteristic can be
approximated by an ideal transformer with some resistive drop
and positive temperature coefficient.
This type of characteristic is close to the impedance
characteristic of a DC power distribution system, both in
behavior (AC dynamic) and absolute value (DC dynamic).
When connected in an array with the same K factor, the VTM
module will inherently share the load current (typically 5%)
with parallel units according to the equivalent impedance
divider that the system implements from the power source to
the point of load.
Some general recommendations to achieve matched array
impedances:
• Dedicate common copper planes within the PCB
to deliver and return the current to the modules.
• Provide the PCB layout as symmetric as possible.
• Apply same input / output filters (if present) to each unit.
16.0 REVERSE INRUSH CURRENT PROTECTION
The VTM48EF015T115A00 provides reverse inrush protection
which prevents reverse current flow until the input voltage is
high enough to first establish current flow in the forward
direction. In the event that there is a DC voltage present on the
output before the VTM module is powered up, this feature
protects sensitive loads from excessive dV/dT during power up
as shown in Figure 21.
If a voltage is present at the output of the VTM module which
satisfies the condition VOUT > VIN • K after a successful power
up the energy will be transferred from secondary to primary.
The input to output ratio of the VTM module will be
maintained. The VTM module will continue to operate in
reverse as long as the input and output voltages are within the
specified range. The VTM48EF015T115A00 has not been
qualified for continuous reverse operation.
TM
VC
PC
IM
R
VTM
Transformer
VIN
+In
+Out
-In
-Out
+
_
For further details see AN:016 Using BCM™ Bus Converters
in High Power Arrays.
A
VIN
ZIN_EQ1
VTM1
ZOUT_EQ1
VTM2
–
CD
E
F
G
H
VC
VIN
ZOUT_EQ2
Supply
RO_2
+
B
Supply
VOUT
RO_1
ZIN_EQ2
R
TM
DC
Load
VIN
VOUT
ZIN_EQn
VTMn
ZOUT_EQn
RO_n
VOUT
Supply
Figure 20 – VTMTM Transformer array
15.0 FUSE SELECTION
In order to provide flexibility in configuring power systems
V• I ChipTM products are not internally fused. Input line fusing
of V• I Chip products is recommended at system level to
provide thermal protection in case of catastrophic failure.
The fuse shall be selected by closely matching system
requirements with the following characteristics:
• Current rating (usually greater than maximum current
of VTM module)
• Maximum voltage rating (usually greater than the maximum
possible input voltage)
• Ambient temperature
• Nominal melting I2t
TM
PC
A: VOUT supply > 0 V
B: VC to -IN > 11.5 V controller wakes-up, PC & TM pulled
high, reverse inrush protection blocks VOUT supplying VIN
C: VIN supply ramps up
D: VIN > VOUT/K, powertrain starts in normal mode
E: VIN supply ramps down
F: VIN > VOUT/K, powertrain transfers reverse energy
G: VOUT ramps down, VIN follows
H: VC turns off
Figure 21 – Reverse inrush protection
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 14 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00
17.0 LAYOUT CONSIDERATIONS
The VTM48EF015T115A00 requires equal current density along
the output J-leads to achieve rated efficiency and output power
level. The negative output J-leads are not connected internally
and must be connected on the board as close to the VTMTM
transformer as possible. The layout must also prevent the high
output current of the VTM48EF015T115A00 from interfering
with the input-referenced signals.
To achieve these requirements, the following layout guidelines
are recommended:
• The total current path length from any point on the V+OUT
J-leads to the corresponding point on the V-OUT J-leads should
be equal (see Figure 21) .
Figure 21 – Equal current path
• Use vias along the negative output J-leads to connect the
negative output to a common power plane.
• Use sufficient copper weight and number of layers to carry
the output current to the load or to the output connectors.
• Be sure to include enough vias along both the positive and
negative J leads to distribute the current among the layers
of the PCB.
• Do not run input-referenced signal traces (VC, PC, TM
and IM) between the layers of the secondary outputs.
• Run the input-referenced signal traces (VC, PC, TM and IM)
such that V-IN shields the signals. See AN:005 FPA Printed
Circuit Board Layout Guidelines for more details.
Figure 22 – Symmetric layout
Equalizing the current paths is most easily accomplished by
centering the VTM module output J-leads between the output
connections of the PCB and by designing the board such that
the layout is symmetric from both sides of the output and from
the front and back ends of the output as shown in Figures 22
and 23.
Figure 23 – Symmetric layout
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 15 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00 PRELIMINARY DATASHEET
17.1 MECHANICAL DRAWING
NOTES:
mm
1. DIMENSIONS ARE inch .
2. UNLESS OTHERWISE SPECIFIED, TOLERANCES ARE:
.X / [.XX] = +/-0.25 / [.01]; .XX / [.XXX] = +/-0.13 / [.005]
3. PRODUCT MARKING ON TOP SURFACE
DXF and PDF files are available on vicorpower.com
17.2 RECOMMENDED LAND PATTERN
4
3
2
1
A
B
C
D
E
F
G
H
J
K
L
M
N
Bottom View
NOTES:
mm
1. DIMENSIONS ARE inch .
2. UNLESS OTHERWISE SPECIFIED, TOLERANCES ARE:
.X / [.XX] = +/-0.25 / [.01]; .XX / [.XXX] = +/-0.13 / [.005]
3. PRODUCT MARKING ON TOP SURFACE
DXF and PDF files are available on vicorpower.com
Signal
Name
+In
–In
IM
TM
VC
PC
+Out
–Out
Designation
M2, M1
M4, M3
N3
N4
N2
N1
A3-L3, A2-L2
A4-L4, A1-L1
Click here to view original mechanical drawing on the Vicor website.
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 16 of 17
v i c o r p o w e r. c o m
VTM48EF015T115A00
Warranty
Vicor products are guaranteed for two years from date of shipment against defects in material or workmanship when in
normal use and service. This warranty does not extend to products subjected to misuse, accident, or improper
application or maintenance. Vicor shall not be liable for collateral or consequential damage. This warranty is extended to
the original purchaser only.
EXCEPT FOR THE FOREGOING EXPRESS WARRANTY, VICOR MAKES NO WARRANTY, EXPRESS OR IMPLIED, INCLUDING,
BUT NOT LIMITED TO, THE WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Vicor will repair or replace defective products in accordance with its own best judgement. For service under this
warranty, the buyer must contact Vicor to obtain a Return Material Authorization (RMA) number and shipping
instructions. Products returned without prior authorization will be returned to the buyer. The buyer will pay all charges
incurred in returning the product to the factory. Vicor will pay all reshipment charges if the product was defective within
the terms of this warranty.
Information published by Vicor has been carefully checked and is believed to be accurate; however, no responsibility is
assumed for inaccuracies. Vicor reserves the right to make changes to any products without further notice to improve
reliability, function, or design. Vicor does not assume any liability arising out of the application or use of any product or
circuit; neither does it convey any license under its patent rights nor the rights of others. Vicor general policy does not
recommend the use of its components in life support applications wherein a failure or malfunction may directly threaten
life or injury. Per Vicor Terms and Conditions of Sale, the user of Vicor components in life support applications assumes
all risks of such use and indemnifies Vicor against all damages.
Vicor’s comprehensive line of power solutions includes high density AC-DC
and DC-DC modules and accessory components, fully configurable AC-DC
and DC-DC power supplies, and complete custom power systems.
Information furnished by Vicor is believed to be accurate and reliable. However, no responsibility is assumed by Vicor for
its use. Vicor components are not designed to be used in applications, such as life support systems, wherein a failure or
malfunction could result in injury or death. All sales are subject to Vicor’s Terms and Conditions of Sale, which are
available upon request.
Specifications are subject to change without notice.
Intellectual Property Notice
Vicor and its subsidiaries own Intellectual Property (including issued U.S. and Foreign Patents and pending patent
applications) relating to the products described in this data sheet. Interested parties should contact Vicor's
Intellectual Property Department.
The products described on this data sheet are protected by the following U.S. Patents Numbers:
5,945,130; 6,403,009; 6,710,257; 6,911,848; 6,930,893; 6,934,166; 6,940,013; 6,969,909; 7,038,917;
7,145,186; 7,166,898; 7,187,263; 7,202,646; 7,361,844; D496,906; D505,114; D506,438; D509,472; and for
use under 6,975,098 and 6,984,965.
Vicor Corporation
25 Frontage Road
Andover, MA, USA 01810
Tel: 800-735-6200
Fax: 978-475-6715
email
Customer Service: [email protected]
Technical Support: [email protected]
V•I CHIP CORP. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 3.4
12/2010
Page 17 of 17
v i c o r p o w e r. c o m