Datasheet

Not Recommended for New Designs
BCM48BH120T120A00
BCM48BH120M120A00
(Formerly VIB0101THJ)
BCM
Bus Converter
TM
S
C
FEATURES
NRTL
US
DESCRIPTION
The V•I ChipTM Bus Converter is a high efficiency (>95%) Sine
Amplitude ConverterTM (SACTM) operating from a 38 to 55 Vdc
primary bus to deliver an isolated 12 V nominal, unregulated
secondary. The SAC offers a low AC impedance beyond the
bandwidth of most downstream regulators, meaning that
input capacitance normally located at the input of a 12 V
regulator can be located at the input to the SAC. Since the
K factor of the BCM48BH120T120A00 is 1/4, that capacitance
value can be reduced by a factor of 16x, resulting in savings of
board area, materials and total system cost.
• 48 Vdc – 12 Vdc 120 W Bus Converter
• High efficiency (>95%) reduces system power
consumption
• High power density (801 W/in3) reduces power system
footprint by >50%
• “Half Chip” V•I Chip package enables surface mount,
low impedance interconnect to system board
• Contains built-in protection features: undervoltage,
The BCM48BH120T120A00 is provided in a V•I Chip package
compatible with standard pick-and-place and surface mount
assembly processes. The V•I Chip package provides flexible
thermal management through its low junction-to-case and
junction-to-board thermal resistance. With high conversion
efficiency the BCM48BH120T120A00 increases overall system
efficiency and lowers operating costs compared to
conventional approaches.
overvoltage lockout, over current protection, short
circuit protection, overtemperature protection.
• Provides enable/disable control, internal temperature
monitoring
• ZVS/ZCS Resonant Sine Amplitude Converter topology
• Less than 50°C temperature rise at full load in typical
applications
TYPICAL APPLICATION
VIN = 38 – 55 V
POUT = 120 W(NOM)
• High End Computing Systems
• Automated Test Equipment
• Telecom Base Stations
• High Density Power Supplies
• Communication Systems
VOUT = 9.5 – 13.75 V (NO LOAD)
K = 1/4
PART NUMBER
DESCRIPTION
BCM48BH120T120A00
-40°C – 125°C TJ, J lead
TYPICAL APPLICATION
POL
enable / disable
switch
TM
PC
POL
SW1
F1
+In
VIN
3.15 A
C1
BCM +Out
POL
VOUT
10 µF
-In
POL
-Out
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 1 of 16
v i c o r p o w e r. c o m
Not Recommended for New Designs
BCM48BH120T120A00
- BCM48BH120M120A00
PRELIMINARY
DATASHEET
ABSOLUTE MAXIMUM RATINGS
CONTROL PIN SPECIFICATIONS
+IN to –IN . . . . . . . . . . . . . . . . . . . . . . . . . -1.0 Vdc – +60 Vdc
PC to –IN . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 Vdc – +20 Vdc
TM to –IN . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 Vdc – +7.0 Vdc
+IN/-IN to +OUT/-OUT . . . . . . . . . . . . . . . . . . . 2250 V (Hi Pot)
+IN/-IN to +OUT/-OUT . . . . . . . . . . . . . . . . . . . . 60 V (working)
+OUT to –OUT . . . . . . . . . . . . . . . . . . . . . . -1.0 Vdc - +16 Vdc
Temperature during reflow . . . . . . . . . . . . . . . . 245°C (MSL 6)
See section 5.0 for further application details and guidelines.
PACKAGE ORDERING INFORMATION
4
3
2
1
A
+Out
+In
B
C
D
E
F
G
H
J
K
-Out
L
M
NC
TM
NC
PC
-In
PC (V•I Chip BCM Primary Control)
The PC pin can enable and disable the BCM. When held below
VPC-DIS the BCM shall be disabled. When allowed to float with
an impedance to –IN of greater than 60 kΩ the module will
start. When connected to another BCM PC pin (either directly,
or isolated through a diode), the BCMs will start simultaneously when enabled. The PC pin is capable of being either
driven high by an external logic signal or internal pull up to 5 V
(operating).
TM (V•I Chip BCM Temperature Monitor)
The TM pin monitors the internal temperature of the BCM
within an accuracy of +5/-5 °C. It has a room temperature
setpoint of ~3.0 V and an approximate gain of 10 mV/°C. It
can source up to 100 uA and may also be used as a “Power
Good” flag to verify that the BCM is operating.
Bottom View
Signal
Name
+In
–In
NC
TM
NC
PC
+Out
–Out
Designation
A1-B1, A2-B2
L1-M1, L2-M2
E1
F2
G1
H2
A3-D3, A4-D4
J3-M3, J4-M4
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 2 of 16
v i c o r p o w e r. c o m
Not Recommended for New Designs
BCM48BH120T120A00 - BCM48BH120M120A00
1.0 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 = 25º unless otherwise noted
ATTRIBUTE
SYMBOL
VIN
dVIN /dt
PQ
Voltage range
dV/dt
Quiescent power
No load power dissipation
PNL
Inrush current peak
IINR-P
DC input current
IIN-DC
K factor
( )
VOUT
CONDITIONS / NOTES
MIN
TYP
MAX
UNIT
38
48
55
1
150
3.0
3.5
Vdc
V/µs
mW
12
A
3.5
A
VIN = 38 – 55 Vdc; See Figure 14
VIN = 46 – 55 Vdc; See Figure 14
97
120
W
VIN = 46 – 55 Vdc
Average POUT < = 120 W, Tpeak < 10 ms
150
W
14
11.3
V
A
PC connected to -IN
VIN = 48 V
VIN = 38 to 55 V
VIN = 48 V COUT = 500 µF,
IOUT = 10.55 A
68
1.7
5.5
K
VIN
Output power (average)
POUT
Output power (peak)
POUT-P
Output voltage
Output current (average)
VOUT
IOUT
1/4
Efficiency (ambient)
η
Efficiency (hot)
Minimum efficiency
(over load range)
Output resistance (ambient)
Output resistance (hot)
Output resistance (cold)
Load capacitance
Switching frequency
Ripple frequency
η
Section 3.0
Pout < =120 W
VIN = 48 V, POUT = 120 W
VIN = 38 V to 55 V, POUT = 100 W
VIN = 48 V, TJ = 100°C, POUT = 120 W
η
24 W < POUT < POUT Max
ROUT
ROUT
ROUT
COUT
FSW
FSW-RP
Output voltage ripple
VOUT-PP
VIN to VOUT (application of VIN)
TON1
PC
PC voltage (operating)
PC voltage (enable)
PC voltage (disable)
PC source current (startup)
PC source current (operating)
PC internal resistance
PC capacitance (internal)
PC capacitance (external)
External PC resistance
PC external toggle rate
PC to VOUT with PC released
PC to VOUT, disable PC
VPC
VPC-EN
VPC-DIS
IPC-EN
IPC-OP
RPC-SNK
CPC_INT
CPC_EXT
RPC
FPC-TOG
Ton2
TPC-DIS
W
TJ = 25°C
TJ = 125°C
TJ = -40°C
8.5
93
90.5
92.6
VIN = 48 V, Pre-applied; See Figure 16
VIN = 48 V, Pre-applied; See Figure 16
%
93.7
%
89
%
35.4
46.1
27.2
44.1
56.1
35.0
1.75
3.50
55.8
69.1
45.7
500
1.90
3.80
mΩ
mΩ
mΩ
uF
MHz
MHz
1.60
3.20
140
355
mV
570
800
ms
4.7
2.0
5.0
2.5
50
100
50
150
5.3
3.0
1.95
300
2
400
588
1000
V
V
V
uA
mA
kΩ
pF
pF
kΩ
Hz
µs
µs
COUT = 0 µF, IOUT = 10.55 A, VIN = 48 V,
Section 8.0
VIN = 48 V, CPC = 0; See Figure 16
Internal pull down resistor
Section 5.0
External capacitance delays PC enable time
Connected to –VIN
94.6
60
60
4
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
1
100
10
Rev. 2.0
12/10
Page 3 of 16
v i c o r p o w e r. c o m
Not Recommended for New Designs
BCM48BH120T120A00
- BCM48BH120M120A00
PRELIMINARY
DATASHEET
1.0 ELECTRICAL CHARACTERISTICS (CONT.)
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 = 25º unless otherwise noted
ATTRIBUTE
SYMBOL
TM
TM accuracy
TM gain
TM source current
TM internal resistance
External TM capacitance
TM voltage ripple
Actm
ATM
ITM
RTM-SNK
CTM
VTM-PP
PROTECTION
Negative going OVLO
Positive going OVLO
Negative going UVLO
Positive going UVLO
Output overcurrent trip
Short circuit protection
trip current
Short circuit protection
response time
Thermal shutdown
junction setpoint
VIN OVLOVIN OVLO+
VIN UVLOVIN UVLO+
IOCP
GENERAL SPECIFICATION
Isolation voltage (Hi-Pot)
Working voltage (IN – OUT)
Isolation vapacitance
Isolation resistance
MTBF
Agency approvals / standards
CONDITIONS / NOTES
MIN
TYP
-5
MAX
UNIT
+5
ºC
mV/°C
uA
kΩ
pF
mV
10
CTM = 0 uF, VIN = 55 V, POUT = 120 W
VIN = 48 V, 25°C
25
40
75
180
100
50
50
250
55.1
55.5
29.1
30.7
12
57.8
58.1
30.8
32.6
20
59.4
59.4
35.4
37.3
25
V
V
V
V
A
40
A
ISSP
15
TSSP
0.8
1.0
1.2
us
TJ-OTP
125
130
135
°C
VHIPOT
Vworking
CIN-OUT
RIN-OUT
2250
1750
60
2150
Unpowered unit
MIL HDBK 217F, 25°C, GB
cTUVus
CE Mark
1350
10
7.1
V
V
pF
MΩ
Mhrs
ROHS 6 of 6
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 4 of 16
v i c o r p o w e r. c o m
Not Recommended for New Designs
BCM48BH120T120A00 - BCM48BH120M120A00
1.1 APPLICATION CHARACTERISTICS
All specifications are at TJ = 25ºC unless otherwise noted. See associated figures for general trend data.
ATTRIBUTE
SYMBOL
No load power
Inrush current peak
PNL
INR-P
Efficiency (ambient)
η
Efficiency (hot – 100°C)
η
Output resistance (-40°C)
Output resistance (25°C)
Output resistance (100°C)
ROUT_C
ROUT_R
ROUT_H
Output voltage ripple
VOUT-PP
VOUT transient (positive)
VOUT-TRAN+
VOUT transient (negative)
VOUT-TRAN-
Undervoltage lockout
response time
Output Overcurrent
Response Time
Overvoltage Lockout
Response Time
CONDITIONS / NOTES
TYP
UNIT
VIN = 48 V, PC enabled; See Figure 1
COUT = 500 µF, POUT = 120 W
VIN = 48 V, POUT = 120 W
COUT = 500 µF
VIN = 48 V, POUT = 120 W
COUT = 500 µF
VIN = 48 V
VIN = 48 V
VIN= 48 V
COUT = 0uF, POUT = 120 W @ VIN = 48,
VIN = 48 V
IOUT_STEP = 0 TO 10.55 A,
ISLEW >10 A/us; See Figure 12
IOUT_STEP = 10.55 A to 0 A,
ISLEW > 10 A/us; See Figure 11
1.75
6
W
A
95
%
94
%
35
44
56
mΩ
mΩ
mΩ
160
mV
1.4
V
1.3
V
2.4
us
4.4
ms
2.4
µs
TUVLO
TOCP
12 < IOCP < 25 A
TOVLO
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 5 of 16
v i c o r p o w e r. c o m
Not Recommended for New Designs
BCM48BH120T120A00
- BCM48BH120M120A00
PRELIMINARY
DATASHEET
Full Load Efficiency vs. Case Temperature
96
95
2.5
Efficiency (%)
2
1.5
94
93
92
91
1
-40
38
40
42
44
46
47
49
51
53
-40ºC
25ºC
96
94
14
94
92
12
10
8
PD
6
84
4
82
2
80
0
4
6
8
Output Load (A)
38 V
VIN :
48 V
55 V
10
38 V
48 V
55 V
84
4
82
2
0
2
4
6
88
8
6
4
82
2
80
0
8
10
48 V
38 V
48 V
55 V
10
12
55 V
38 V
48 V
55 V
ROUT vs. CaseTemperature
12
50
45
40
35
30
25
20
-40
-20
0
20
40
60
80
100
Temperature (°C)
Output Load (A)
VIN :
8
55
ROUT (m )
12
PD
38 V
VIN:
60
Power Dissipation (W)
Efficiency (%)
14
6
6
PD
Figure 4 – Efficiency and power dissipation at 25°C (case); VIN
10
4
12
8
86
0
90
2
14
Output Load (A)
η
0
η
88
16
84
55 V
10
Efficiency & Power Dissipation 100°C Case
86
48 V
90
12
96
92
100
80
Figure 3 – Efficiency and power dissipation at -40°C (case); VIN
94
80
16
92
Efficiency (%)
Efficiency (%)
90
Power Dissipation (W)
16
2
60
Efficiency & Power Dissipation 25°C Case
Efficiency & Power Dissipation -40°C Case
0
40
Figure 2 – Full load efficiency vs. temperature; VIN
96
86
20
38 V
VIN :
100ºC
Figure 1 – No load power dissipation vs. VIN; TCASE
88
0
Case Temperature (C)
Input Voltage (V)
TCASE:
-20
55
Power Dissipation (W)
No Load Power Dissipation (W)
No Load Power Dissipation vs. Line
3
38 V
48 V
55 V
Figure 5 – Efficiency and power dissipation at 100°C (case); VIN
I OUT :
1.05 A
10.55 A
Figure 6 – ROUT vs. temperature vs. IOUT
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 6 of 16
v i c o r p o w e r. c o m
Not Recommended for New Designs
BCM48BH120T120A00 - BCM48BH120M120A00
Output Voltage Ripple 25°C vs. IOUT
180
160
Vripple (mV)
140
120
100
80
60
40
20
0
0
2
4
6
8
10
IOUT (A)
Figure 7 – Vripple vs. IOUT ; 48 Vin, no external capacitance
Figure 8 – PC to VOUT startup waveform
Figure 9 – VIN to VOUT startup waveform
Figure 10 – Output voltage and input current ripple, 48 Vin, 120 W
no cOUT
Figure 11 – Positive load transient (0 – 11.3 A)
Figure 12 – Negative load transient (11.3 A – 0 A)
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 7 of 16
v i c o r p o w e r. c o m
Not Recommended for New Designs
BCM48BH120T120A00
- BCM48BH120M120A00
PRELIMINARY
DATASHEET
POUT (W)
120
97
38
Figure 13 – PC disable waveform, 48 VIN, 500 µF COUT full load
46
VIN (VDC)
55
Figure 14 – POUT derating vs. VIN
2.0 PACKAGE/MECHANICAL SPECIFICATIONS
All specifications are at TJ = 25ºC unless otherwise noted. See associated figures for general trend data.
ATTRIBUTE
SYMBOL
L
W
H
Vol
F
No Heatsink
No Heatsink
Power Density
PD
No Heatsink
Weight
W
Operating Temperature
Storage Temperature
Thermal Impedance
Thermal Capacity
Peak Compressive Force
Applied to Case (Z-axis)
TJ
TST
ØJC
TYP
MAX
-40
-40
UNIT
Junction to Case
125
125
2.7
°C
°C
°C/W
Ws/°C
3.0
lbs
225
245
150
3
6
VDC
VDC
°C
°C
s
°C/s
°C/s
5
Supported by J-leads only
ESDHBM
ESDMM
ESD Rating
Peak Temperature During Reflow
Peak Time Above 183°C
Peak Heating Rate During Reflow
Peak Cooling Rate Post Reflow
[b]
MIN
21.7 / 0.854 22.0 / 0.866 22.3 / 0.878 mm/in
16.37 / 0.644 16.50 / 0.650 16.63 / 0.655 mm/in
6.48 / 0.255 6.73 / 0.265 6.98 / 0.275 mm/in
2.44 / 0.150
cm3/in3
3.6 / 0.56
cm2/in2
801
W/in3
3
W/cm
49
0.28/8
oz/g
Nickel (0.51-2.03 µm)
Palladium (0.02-0.15 µm)
Gold (0.003-0.05 µm)
Lead Finish
[a]
CONDITIONS / NOTES
Length
Width
Height
Volume
Footprint
Human Body Model[a]
Machine Model[b]
MSL 5
MSL 6
2.5
1500
400
1.5
1.5
JEDEC JESD 22-A114C.01
JEDED JESD 22-A115-A
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 8 of 16
v i c o r p o w e r. c o m
Not Recommended for New Designs
BCM48BH120T120A00 - BCM48BH120M120A00
2.1 MECHANICAL DRAWING
mm
(inch)
BOTTOM VIEW
TOP VIEW ( COMPONENT SIDE )
NOTES:
mm
2. DIMENSIONS ARE inch .
UNLESS OTHERWISE SPECIFIED, TOLERANCES ARE:
3. .X / [.XX] = +/-0.25 / [.01]; .XX / [.XXX] = +/-0.13 / [.005]
4. PRODUCT MARKING ON TOP SURFACE
DXF and PDF files are available on vicorpower.com
2.2 RECOMMENDED LAND PATTERN
4
RECOMMENDED LAND PATTERN
( COMPONENT SIDE SH OWN )
3
2
1
A
+Out
+In
B
C
NC
TM
NC
PC
-In
D
E
F
G
H
J
K
-Out
L
M
Bottom View
NOTES:
3. .X / [.XX] = +/-0.25 / [.01]; .XX / [.XXX] = +/-0.13 / [.005]
mm
2. DIMENSIONS ARE inch .
UNLESS OTHERWISE SPECIFIED, TOLERANCES ARE:
4. PRODUCT MARKING ON TOP SURFACE
DXF and PDF files are available on vicorpower.com
Signal
Name
+In
–In
NC
TM
NC
PC
+Out
–Out
Designation
A1-B1, A2-B2
L1-M1, L2-M2
E1
F2
G1
H2
A3-D3, A4-D4
J3-M3, J4-M4
2.3 RECOMMENDED LAND PATTERN FOR PUSH PIN HEATSINK
Notes:
1. Maintain 3.50 (0.138) Dia. keep-out zone
free of copper, all PCB layers.
2. (A) minimum recommended pitch is 24.00 (0.945)
this provides 7.50 (0.295) component
edge–to–edge spacing, and 0.50 (0.020)
clearance between Vicor heat sinks.
(B) Minimum recommended pith is 25.50 (1.004).
This provides 9.00 (0.354) component
edge–to–edge spacing, and 2.00 (0.079)
clearance between Vicor heat sinks.
3. V•I Chip land pattern shown for reference
only, actual land pattern may differ.
Dimensions from edges of land pattern
to push–pin holes will be the same for
all half size V•I Chip Products.
4. RoHS compliant per CST–0001 latest revision.
5. Unless otherwise specified:
Dimensions are mm (inches)
tolerances are:
x.x (x.xx) = ±0.3 (0.01)
x.xx (x.xxx) = ±0.13 (0.005)
6. Plated through holes for grounding clips (33855)
shown for reference, Heatsink orientation and
device pitch will dictate final grounding solution.
(NO GROUNDING CLIPS)
(WITH GROUNDING CLIPS)
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 9 of 16
v i c o r p o w e r. c o m
Not Recommended for New Designs
BCM48BH120T120A00
- BCM48BH120M120A00
PRELIMINARY
DATASHEET
3.0 POWER, VOLTAGE, EFFICIENCY RELATIONSHIPS
Because of the high frequency, fully resonant SAC topology,
power dissipation and overall conversion efficiency of BCM
converters can be estimated as shown below.
OUTPUT
POWER
INPUT
POWER
Key relationships to be considered are the following:
1. Transfer Function
P R OUT
a. No load condition
P NL
VOUT = VIN • K
Eq. 1
Figure 15 – Power transfer diagram
Where K (transformer turns ratio) is constant
for each part number
b. Loaded condition
VOUT = Vin • K – IOUT • ROUT
Eq. 2
2. Dissipated Power
The two main terms of power losses in the
BCM module are:
- No load power dissipation (PNL) defined as the power
used to power up the module with an enabled power
train at no load.
- Resistive loss (ROUT) refers to the power loss across
the BCM modeled as pure resistive impedance.
PDISSIPATED ~
~ PNL + PROUT
Eq. 3
Therefore, with reference to the diagram shown in Figure 15
POUT = PIN – PDISSIPATED = PIN – PNL – PROUT
Eq. 4
Notice that ROUT is temperature and input voltage dependent
and PNL is temperature dependent (See Figure 15).
The above relations can be combined to calculate the overall module efficiency:
η =
POUT
PIN
=
PIN – PNL – PROUT
PIN
=
VIN • IIN – PNL – (IOUT)2 • ROUT
VIN • IIN
=1–
(
PNL + (IOUT)2 • ROUT
VIN • IIN
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
)
Eq. 5
Rev. 2.0
12/10
Page 10 of 16
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
NL
5V
2.5 V
5V
3V
PC
VUVLO+
VUVLO–
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
1
A
E: TON2
F: TOCP
G: TPC–DIS
H: TSSP**
B
D
1: Controller start
2: Controller turn off
3: PC release
C
*Min value switching off
**From detection of error to power train shutdown
A: TON1
B: TOVLO*
C: Max recovery time
D:TUVLO
0.4 V
3 V @ 27°C
TM
LL • K
Vout
C
500mS
before retrial
3V
VIN
VOVLO+
VOVLO–
2
F
4: PC pulled low
5: PC released on output SC
6: SC removed
IOCP
ISSP
IOUT
E
3
G
4
Notes:
H
5
– Timing and voltage is not to scale
– Error pulse width is load dependent
6
Not Recommended for New Designs
BCM48BH120T120A00 - BCM48BH120M120A00
4.0 OPERATING
Figure 16 – Timing diagram
Rev. 2.0
12/10
Page 11 of 16
Not Recommended for New Designs
BCM48BH120T120A00
- BCM48BH120M120A00
PRELIMINARY
DATASHEET
5.0 USING THE CONTROL SIGNALS TM AND PC
The PC control pin can be used to accomplish the following
functions:
• Delayed start: At start-up, PC pin will source a constant
100 uA current to the internal RC network. Adding an
external capacitor will allow further delay in reaching the
2.5 V threshold for module start.
• Synchronized start up: In a parallel module array, PC pins
shall be connected in order to ensure synchronous start of all
the units. While every controller has a calibrated 2.5 V
reference on PC comparator, many factors might cause
different timing in turning on the 100 uA current source on
each module, i.e.:
– Different VIN slew rate
– Statistical component value distribution
By connecting all PC pins, the charging transient will be
shared and all the modules will be enabled synchronously.
• Auxiliary voltage source: Once enabled in regular
operational conditions (no fault), each BCM PC provides a
regulated 5 V, 2 mA voltage source.
• Output disable: PC pin can be actively pulled down in order
to disable module operations. Pull down impedance shall be
lower than 1 kΩ and toggle rate lower than 1 Hz.
• Fault detection flag: The PC 5 V voltage source is internally
turned off as soon as a fault is detected. After a minimum
disable time, the module tries to re-start, and PC voltage is
re-enabled. For system monitoring purposes (microcontroller
interface) faults are detected on falling edges of PC signal.
It is important to notice that PC doesn’t have current sink
capability (only 150 kΩ typical pull down is present),
therefore, in an array, PC line will not be capable of disabling
all the modules if a fault occurs on one of them.
6.0 FUSE SELECTION
V•I Chips are not internally fused in order to provide flexibility
in configuring power systems. Input line fusing of V•I Chips is
recommended at system level, in order 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 BCM current)
• Maximum voltage rating (usually greater than the maximum
possible input voltage)
• Ambient temperature
• Nominal melting I2t
• Recommended fuse: 3.15 A Little Fuse Nano2 Fuse
The 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 x100. (i.e. 3.0 V = 300 K = 27ºC). It is important to
remember that V•I chips are multi-chip modules, whose
temperature distribution greatly vary for each part number as
well with input/output conditions, thermal management and
environmental conditions. Therefore, TM cannot 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. After a minimum
disable time, the module tries to re-start, and TM voltage is
re-enabled.
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 12 of 16
v i c o r p o w e r. c o m
Not Recommended for New Designs
BCM48BH120T120A00 - BCM48BH120M120A00
7.0 CURRENT SHARING
The SAC 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 same K factor), the BCM
module will inherently share the load current with parallel
units, according to the equivalent impedance divider that the
system implements from the power source to the point of load.
It is important to notice that, when successfully started, BCMs
are capable of bidirectional operations (reverse power transfer
is enabled if the BCM input falls within its operating range and
the BCM is otherwise enabled). In parallel arrays, because of
the resistive behavior, circulating currents are never experienced,
because of energy conservation law.
General recommendations to achieve matched array impedances
are (see also AN016 for further details):
• to dedicate common copper planes within the PCB to
deliver and return the current to the modules
• to make the PCB layout as symmetric as possible
• to apply same input/output filters (if present) to each unit
Figure 17 – BCM Array
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 13 of 16
v i c o r p o w e r. c o m
Not Recommended for New Designs
BCM48BH120T120A00
- BCM48BH120M120A00
PRELIMINARY
DATASHEET
8.0 INPUT AND OUTPUT FILTER DESIGN
A major advantage of SAC systems versus conventional PWM
converters is that the transformers do 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 achieve
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 BCM dynamic response, the
impedance presented to its input terminals must be low
from DC to approximately 5 MHz. The connection of the
V•I Chip to its power source should be implemented with
minimal distribution inductance. If the interconnect
inductance exceeds 100 nH, the input should be bypassed
with a RC damper to retain low source impedance and
stable operation. With an interconnect inductance of
200 nH, the RC damper may be as high as 47 µF in series
with 0.3 Ω. A single electrolytic or equivalent low-Q
capacitor may be used in place of the series RC bypass.
Total load capacitance at the output of the BCM shall not
exceed the specified maximum. Owing to the wide bandwidth
and low output impedance of the BCM, low frequency bypass
capacitance and significant energy storage may be more
densely and efficiently provided by adding capacitance at the
input of the BCM. At frequencies <500 kHz the BCM appears
as an impedance of ROUT between the source and load.
Within this frequency range capacitance at the input appears
as effective capacitance on the output per the relationship
defined in Eq. 6.
COUT =
CIN
K2
Eq. 6
This enables a reduction in the size and number of capacitors
used in a typical system.
2.Further reduce input and/or output voltage ripple without
sacrificing dynamic response:
Given the wide bandwidth of the BCM, 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 BCM multiplied by its
K factor. This is illustrated in Figures 11 and 12.
3.Protect the module from overvoltage transients imposed
by the system that would exceed maximum ratings and
cause failures:
The V•I Chip input/output voltage ranges shall 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. A criterion for protection is the maximum amount of
energy that the input or output switches can tolerate if
avalanched.
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 14 of 16
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
TM
PC
-Vin
+Vin
560 pF
2.5 V
40 K
5V
Voltage dependent
temperature sensor
2.5 V
One shot
delay
320/540 ms
2 mA
PC Pull-Up
& Source
150 K
1.5 k
100 uA
UVLO
OVLO
18.5 V
Wake-Up Power
and Logic
Vref
(125°C)
Primary
Gate
Drive
supply
Min. off
time and
restart
Enable
Modulator
Vref
Over-Current
Protection
Slow
current
limit
Fast
current
limit
Differential primary
current sensing
Primary Stage &
Resonant Tank
-Vout
+Vout
Not Recommended for New Designs
BCM48BH120T120A00 - BCM48BH120M120A00
Figure 1 – BCM behavioral block diagram
V•I CHIP INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 15 of 16
Not Recommended for New Designs
BCM48BH120T120A00
- BCM48BH120M120A00
PRELIMINARY
DATASHEET
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;
7,166,898; 7,187,263; 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 INC. (A VICOR COMPANY) 25 FRONTAGE RD. ANDOVER, MA 01810 800-735-6200
Rev. 2.0
12/10
Page 16 of 16
v i c o r p o w e r. c o m