SynQor BQ55120QEX50 On/off control referenced to input side Datasheet

Technical
Specification
BQ55120QEx50
35-55V
12.0V
50A
2000V dc
Quarter-brick
Continuous Input
Output
Max Current
Isolation
DC-DC Converter
The BusQor BQ55120QEx50 bus converter is a nextgeneration, board-mountable, isolated, fixed switching
frequency dc/dc converter that uses synchronous rectification
to achieve extremely high conversion efficiency. The power
dissipated by the converter is so low that a heatsink is not
required, which saves cost, weight, height, and application
effort. The BusQor series provides an isolated step down
voltage from 48V to 12 or 9.6V intermediate bus with no
regulation in a standard “quarter-brick” module. BusQor
converters are ideal for creating the mid-bus voltage
required to drive point-of-load (non-isolated) converters in
intermediate bus architectures.
Bus
High efficiency, 96.8 % at full rated load current at full load
Delivers full power with minimal derating - no heatsink required
Operating input voltage range: 35-55V dc
Fixed frequency switching provides predictable EMI
No minimum load requirement
Control Features
• On/Off control referenced to input side
• Inherent current share (by droop method) for high current and
parallel applications.
Mechanical Features
•
•
•
•
•
Bus
Converter
BQ55120QEA50NRS-G
Operational Features
•
•
•
•
•
®
Safety Features
• UL 60950-1:2007
Industry standard size: 1.45” x 2.3” (36.8x58.4mm)
Total OF height: 0.467” (11.86mm)
Total open frame weight: 1.5 oz (42 g)
Total Baseplate height: 0.517" (13.13mm)
Total Baseplate weight: 2.7 oz (78 g)
• EN60950-1/A11:2009/A1:2010
• CAN/CSA-C22.2 No. 60950-1:2007
• IEC 61000-4-2
Contents
Page No.
Protection Features
• Input under-voltage lockout and over-voltage shutdown protects
against abnormal input voltages
• Output current limit and short circuit protection (auto recovery)
• Output over-voltage protection
• Thermal shutdown
Product # BQ55120QEx50
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Open Frame Mechanical Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Baseplated Mechanical Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Standards and Qualifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Technical Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Application Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Ordering Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
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Doc.# 005-0005571 Rev. F
10/03/11
Page 1
Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Open Frame Mechanical
1.450
[ 36.83]
.600
[15.24 ]
5
.467 ±.020
[ 11.86 ±0.5]
OVERALL HEIGHT
4
.056 ±.010
[ 1.42 ±0.25 ]
BOTTOMSIDE
CLEARANCE
2.300
[ 58.42 ]
2.000
[ 50.8 ]
.143
[ 3.63 ]
1
2
3
.425
[ 10.8 ]
.110
[ 2.79 ]
SEE NOTE 3
.300
[ 7.62 ]
.600
[ 15.24 ]
NOTES
PIN DESIGNATIONS
1) Pins 1-3 are 0.040” (1.02mm) diameter with 0.080” (2.03 mm)
diameter standoff shoulders.
2) Pins 4-5 are 0.062” (1.57 mm) diameter with 0.100” (2.54 mm)
diameter standoff shoulders.
3) Other pin lengths available. Recommended pin length is 0.03”
(0.76mm) greater than the PCB thickness.
4) All Pins: Material - Copper Alloy
Finish: Matte Tin over Nickel plate
5) Undimensioned components are shown for visual reference only.
6) All dimensions in inches (mm)
Tolerances: x.xx +/-0.02 in. (x.x +/-0.5mm)
x.xxx +/-0.010 in. (x.xx +/-0.25mm)
Pin
Name
Function
1 Vin(+) Positive input voltage
2 ON/OFF Logic control input to turn converter on/off.
3 Vin(–) Negative input
4 Vout(–) Negative output
5 Vout(+) Positive output
7) Weight: 1.5 oz (42 g) typical
8) Workmanship: Meets or exceeds IPC-A-610C Class II
9) UL/TUV standards require a clearance of 0.04” (1.02mm) around
primary areas of the module.
10) The flanged pins are designed to permit surface mount soldering
(allowing to avoid the wave soldering process) through the use of the
flanged pin-in-paste technique.
Product # BQ55120QEx50
Phone 1-888-567-9596
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Doc.# 005-0005571 Rev. F
10/03/11
Page 2
Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Baseplated Mechanical Diagram
1.510[38,35]
1.100[27,94]
.517±.030
[ 13,13±0,76 ]
OVERALL HEIGHT
.600
[15,24]
.053±.030
[ 1,35±0,76 ]
BOTTOMSIDE
CLEARANCE
4
5
2.340
[59,44]
1.900
[48,26]
2.000
[50,8]
.750
[19,05]
1
2
3
.060
[1,52]
.160±.0154,06±0,38[]
.455±.01511,56±0,38[]
.110
[2,79]
SEE NOTE 4
M3 INSERTS
(3 PLACES)
(SEE NOTES 1&2
.300[7,62]
.600[15,24]
.850[21,59]
NOTES
PIN DESIGNATIONS
1) M3 screws used to bolt unit's baseplate to other surfaces such as
heatsinks must not exceed 0.10" (2.54mm) depth below the surface
of the baseplate.
2)
3)
4)
5)
Applied torque per screw should not exceed 6in-lb (0.7nm)
Baseplate flatness tolerance is 0.004" (.10mm) TIR for surface
Other pin extension lengths available
Pins 1-3 are 0.040" (1.02mm) dia. with 0.080" (2.03mm) dia.
standoff shoulders
6) Pins 4 and 5 are 0.062" (1.57mm) dia. with 0.100" (2.54mm) dia.
standoff shoulders
7) All pins: Material: Copper Alloy
Finish: Matte Tin over Nickel plate
8) Undimensioned components are shown for visual reference only
9) Weight: 2.7 oz (78 g) typical
10) All dimensions in inches(mm)
Tolerances: x.xxin +/-0.02 (x.xmm +/-0.5mm)
x.xxxin +/-0.010 (x.xxmm +/-0.25mm)
Product # BQ55120QEx50
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Pin
Name
Function
1 Vin(+) Positive input voltage
2 ON/OFF Logic control input to turn converter on/off.
3 Vin(–) Negative input
4 Vout(–) Negative output
5 Vout(+) Positive output
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Doc.# 005-0005571 Rev. F
10/03/11
Page 3
Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Technical Specification
BQ55120QEx50 Electrical Characteristics
Ta = 25 °C, airflow rate = 300 LFM, Vin = 48V dc unless otherwise noted; full operating temperature range is -40 °C to +100 °C ambient temperature
with appropriate power derating. Specifications subject to change without notice.
Parameter
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Non-Operating
Operating
Isolation Voltage
Input to Output
Operating Temperature
Storage Temperature
Voltage at ON/OFF input pin
INPUT CHARACTERISTICS
Operating Input Voltage Range
Input Under-Voltage Lockout
Turn-On Voltage Threshold
Turn-Off Voltage Threshold
Lockout Voltage Hysteresis
Input Over-Voltage Shutdown
Turn-On Voltage Threshold
Turn-Off Voltage Threshold
Maximum Input Current
No-Load Input Current
Disabled Input Current
Input Reflected-Ripple Current
Input Terminal-Ripple Current
Recommended Input Fuse (see Note 1)
Recommended External Input Capacitance
Input Filter Component Values (C\L\C)
OUTPUT CHARACTERISTICS
Output Voltage Set Point
Output Voltage Regulation
Over Line
Over Load
Over Temperature
Total Output Voltage Range
Output Voltage Ripple and Noise
Peak-to-Peak
RMS
Operating Output Current Range
Output DC Current-Limit Inception
Output DC Current-Limit Shutdown Voltage
Back-Drive Current Limit while Disabled
Maximum Output Capacitance
DYNAMIC CHARACTERISTICS
Output Voltage during Load Current Transient
Step Change in Output Current (0.1 A/µs)
Settling Time
Turn-On Transient
Turn-On Time (with 5mF output capacitance)
Start-Up Inhibit Time
Output Voltage Overshoot
Product # BQ55120QEx50
Min.
Typ.
Max.
0
35
48
60
55
V
V
2000
100
125
18
V
°C
°C
V
55
V
-40
-55
-2
35
48
33.4
31
2.4
47
0.47\11
V
V
V
V
V
V
A
mA
mA
mA
mA
A
µF
µH\µF
12.0
V
40\4.75
5.2\500
2\200
%\V
%\mV
%\mV
V
56.9
59.2
8.5
10
600
14.5
110
12.0
20
20
8.300
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Units Notes & Conditions
13.750
75
30
0
125
50
65
10.4
10
5,000
450
100
10
200
0
15
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mV
mV
A
A
V
mA
µF
Continuous
Continuous
RMS through 10µH inductor
RMS, full load
Fast blow external fuse recommended
Typical ESR 0.1-0.2 Ω
Internal values
No load Vin = 48 V
Over sample, line, load, temperature & life
20 MHz bandwidth; see Note 2
Full load
Full load
Subject to thermal derating
Output Voltage 10% Low
Vin = 48 V
Negative current drawn from output
12.0 Vout at Half Load Resistive Load
mV
µs
50% to 75% to 50% Iout max
To within 1% Vout nom
ms
ms
%
Half load, Vout=90% nom.
-40 °C to +125 °C; Figure E
5 mF load capacitance
Doc.# 005-0005571 Rev. F
10/03/11
Page 4
Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Technical Specification
BQ55120QEx50 Electrical Characteristics (continued)
Ta = 25 °C, airflow rate = 300 LFM, Vin = 48V dc unless otherwise noted; full operating temperature range is -40 °C to +100 °C ambient temperature
with appropriate power derating. Specifications subject to change without notice.
Parameter
Min.
Typ.
Max.
Units Notes & Conditions
ISOLATION CHARACTERISTICS
Isolation Voltage (dielectric strength)
2000
V
See Absolute Maximum Ratings
Isolation Resistance
30
MΩ
Isolation Capacitance (input to output)
470
pF
See Note 3
TEMPERATURE LIMITS FOR POWER DERATING CURVES
Semiconductor Junction Temperature
125
°C
Package rated to 150 °C
Board Temperature
125
°C
UL rated max operating temp 130 °C
Transformer Core Temperature
140
°C
Maximum Baseplate Temperature, Tb
100
°C
EFFICIENCY
100% Load
96.8
%
50% Load
97
%
FEATURE CHARACTERISTICS
Switching Frequency
133
150
165
kHz
ON/OFF Control (Option P)
Off-State Voltage
-1
0.8
V
On-State Voltage
2.4
18
V
ON/OFF Control (Option N)
Off-State Voltage
2.4
18
V
On-State Voltage
-1
0.8
V
ON/OFF Controll (Either Option)
Application note Figure B
Pull-Up Voltage
5
V
Pull-Up Resistance
100
kΩ
Over-Temperature Shutdown OTP Trip Point
140
150
°C
Average PCB Temperature
Over-Temperature Shutdown Restart Hysteresis
10
°C
RELIABILITY CHARACTERISTICS
Calculated MTBF (Telcordia) TR-NWT-000332
3.7
106 Hrs. 80% load, 300LFM, 40 °C Ta
Calculated MTBF (MIL-217) MIL-HDBK-217F
2.9
106 Hrs. 80% load, 300LFM, 40 °C Ta
Field Demonstrated MTBF
106 Hrs. See our website for details
Note 1: UL’s product certification tests were carried out using 20A fast blow fuse. Fuse interruption characteristics have to be taken into account while
designing input traces. User should ensure that Input trace is capable of withstanding fault currents
Note 2: For applications requiring reduced output voltage ripple and noise, consult SynQor applications support (e-mail: [email protected])
Note 3: Isolation capacitance can be added external to the module.
Product # BQ55120QEx50
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Doc.# 005-0005571 Rev. F
10/03/11
Page 5
Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Technical Specification
Standards and Qualifications
Parameter
Notes & Conditions
STANDARDS COMPLIANCE
UL 60950-1:2007
Basic insulation
EN60950-1/A11:2009/A1:2010
CAN/CSA-C22.2 No. 60950-1:2007
IEC 61000-4-2
ESD test, 8 kV - NP, 15 kV air - NP (Normal Performance)
Note: An external input fuse must always be used to meet these safety requirements. Contact SynQor for official safety certificates on new
releases or download from the SynQor website.
Parameter
QUALIFICATION TESTING
Life Test
Vibration
Mechanical Shock
Temperature Cycling
Power/Thermal Cycling
Design Marginality
Humidity
Solderability
Product # BQ55120QEx50
# Units
32
5
5
10
5
5
5
15 pins
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Test Conditions
95% rated Vin and load, units at derating point, 1000 hours
10-55 Hz sweep, 0.060" total excursion, 1 min./sweep, 120 sweeps for 3 axis
100g minimum, 2 drops in x, y and z axis
-40 °C to 100 °C, unit temp. ramp 15 °C/min., 500 cycles
Toperating = min to max, Vin = min to max, full load, 100 cycles
Tmin-10 °C to Tmax+10 °C, 5 °C steps, Vin = min to max, 0-105% load
85 °C, 85% RH, 1000 hours, continuous Vin applied except 5 min/day
MIL-STD-883, method 2003
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Doc.# 005-0005571 Rev. F
10/03/11
Page 6
Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Technical Figures
100
98.0
95
97.5
97.0
85
Efficiency (%)
Efficiency (%)
90
80
75
70
96.5
96.0
35 Vin
25º C
48 Vin
65
55 Vin
60
0
10
20
30
40
Load Current (A)
40º C
95.5
95.0
100
50
Figure 1: Efficiency at nominal output voltage vs. load current for minimum,
55º C
200
Air Flow (LFM)
300
400
Figure 2: Efficiency at nominal output voltage and 60% rated power vs. airflow
rate for ambient air temperatures of 25°C, 40°C, and 55°C (nominal input
voltage).
nominal, and maximum input voltage at 25°C.
13
30
Power Dissipation (W)
Power Dissipation (W)
25
20
15
10
35 Vin
5
12
11
10
25º C
40º C
48 Vin
55º C
55 Vin
0
0
10
20
30
40
Load Current (A)
9
100
50
Figure 3: Power dissipation at nominal output voltage vs. load current for
minimum, nominal, and maximum input voltage at 25°C.
200
Air Flow (LFM)
300
400
Figure 4: Power dissipation at nominal output voltage and 60% rated power
vs. airflow rate for ambient air temperatures of 25°C, 40°C, and 55°C (nominal
input voltage).
60
Semiconductor junction temperature is
within 1°C of surface temperature
50
Iout (A)
40
30
20
400
300
200
100
10
LFM (2.0
LFM (1.5
LFM (1.0
LFM (0.5
m/s)
m/s)
m/s)
m/s)
0
25
40
55
70
85
Ambient Air Temperature (ºC)
Figure 5: Maximum output power-derating curve vs. ambient air temperature for
airflow rates of 100 LFM through 400 LFM with air flowing from pin 1 to pin 3
(nominal input voltage).
Product # BQ55120QEx50
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Figure 6: Thermal plot of converter at 37.3 A load current (434 W) with 55°C air
flowing at the rate of 200 LFM. Air is flowing across the converter from pin 1 to
pin 3 (nominal input voltage).
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Doc.# 005-0005571 Rev. F
10/03/11
Page 7
Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Technical Figures
60
50
Iout (A)
40
30
20
400
300
200
100
10
LFM (2.0
LFM (1.5
LFM (1.0
LFM (0.5
m/s)
m/s)
m/s)
m/s)
0
25
40
55
70
85
Semiconductor junction temperature is
within 1°C of surface temperature
Ambient Air Temperature (ºC)
Figure 7: Maximum output power derating curves vs. ambient air temperature
for airflow rates of 100 LFM through 400 LFM with air flowing across the
converter from output to input (nominal input voltage).
Figure 8: Thermal plot of converter at 35.0 A load current (407 W) with 55°C air
flowing at the rate of 200 LFM. Air is flowing across the converter from output
to input (nominal input voltage).
Figure 9: Turn-on transient at 50% load (resistive load) (5 ms/div). Load cap:
5 mF output capacitance. Input voltage pre-applied. Ch 1: Vout (2 V/div), Ch 2:
ON/OFF input (2 V/div).
Figure 10: Turn-on transient at zero load (5 ms/div). Load cap: 5 mF output
capacitance. Ch 1: Vout (2 V/div), Ch 2: ON/OFF input (2 V/div).
Figure 11: Output voltage response to step-change in load current (50%-75%50% of Iout(max); dI/dt = 0.1A/µs). Load cap: 15µF tantalum cap and 1µF
ceramic cap. Ch 1: Vout (500mV/div), Ch 2: Iout (20A/div).
Figure 12: Output voltage response to step-change in load current (50%-75%50% of Iout(max): dI/dt = 1A/µs). Load cap: 15µF, 30 mΩ ESR tantalum cap
and 1µF ceramic cap. Ch 1: Vout (500 mV/div), Ch 2: Iout (20A/div).
Product # BQ55120QEx50
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Doc.# 005-0005571 Rev. F
10/03/11
Page 8
Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Technical Figures
Input
Reflected
Ripple
Current
source
impedance
Input
Terminal
Ripple
Current
iS
iC
Output
Voltage
Ripple
DC-DC
Converter
VOUT
VSOURCE
electrolytic
capacitor
ceramic
capacitor
tantalum
capacitor
Figure 13: Test set-up diagram showing measurement points for Input Terminal
Ripple Current (Figure 14), Input Reflected Ripple Current (Figure 15) and
Output Voltage Ripple (Figure 16).
Figure 14: Input Terminal Ripple Current, ic, at full rated output current and
nominal input voltage with 10µH source impedance and 47µF electrolytic
capacitor (500 mA/div). See Figure 13.
Figure 15: Input reflected ripple current, is, through a 10 µH source inductor,
using a 47µF electrolytic input capacitor (50 mA/div). See Figure 13.
Figure 16: Output voltage ripple at nominal input voltage and rated load current
(100 mV/div). Load capacitance: 1µF ceramic capacitor and 15µF tantalum
capacitor. Bandwidth: 20 MHz. See Figure 13.
14
Output Voltage (V)
12
10
8
6
4
35 Vin
48 Vin
2
55 Vin
0
0
10
20
30
40
Load Current (A)
50
60
70
Figure 17: Output voltage vs. load current for different input voltages showing
typcial current limit curves.
Product # BQ55120QEx50
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Figure 18: Load current (50A/div) as a function of time when the converter
attempts to turn on into a 1 m-ohm short circuit. Top trace (2ms/div) is an
expansion of the on-time portion of the bottom trace.
www.synqor.com
Doc.# 005-0005571 Rev. F
10/03/11
Page 9
Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Application Section
BASIC OPERATION AND FEATURES
CONTROL FEATURES
With voltages dropping and currents rising, the economics
of an Intermediate Bus Architecture (IBA) are becoming
more attractive, especially in systems requiring multiple
low voltages. IBA systems separate the role of isolation and
voltage scaling from regulation and sensing. The BusQor
series bus converter provides isolation and an unregulated
voltage step down in one compact module, leaving regulation
to simpler, less expensive non-isolated converters.
REMOTE ON/OFF (Pin 2): The ON/OFF input, Pin 2,
permits the user to control when the converter is on or off.
This input is referenced to the return terminal of the input
bus, Vin(-). There are two versions of the converter that
differ by the sense of the logic used for the ON/OFF input.
In Figure A below, the BusQor module provides the isolation
stage of the IBA system. The isolated bus then distributes
power to the non-isolated buck regulators to generate the
required voltage levels at the points of load. In this case, the
bucks are represented with SynQor’s NiQor series of nonisolated DC/DC converters. In many applications requiring
multiple low voltage outputs, significant savings can be
achieved in board space and overall system costs
When designing an IBA system with bus converters, the
designer can select from a variety of bus voltages. While
there is no universally ideal bus voltage, most designs
employ one of the following: 12V, 9V, 7.5V, 5V, or 3.3V.
Higher bus voltages can lead to lower efficiency for the buck
regulators but are more efficient for the bus converter and
provide lower board level distribution current. Lower bus
voltages offer the opposite trade offs.
In the positive logic version, the ON/OFF input is active
high (meaning that a high turns the converter on). In the
negative logic version, the ON/OFF signal is active low
(meaning that a low turns the converter on). Figure B is a
detailed look of the internal ON/OFF circuitry.
Vin(+)
5V
5V
124K
On/Off
49.9K
TTL
100k
Vin(-)
Figure B: Internal ON/OFF pin circuitry
SynQor’s 12 Vout BusQor module acts as a true dc
transformer. The output voltage is proportional to the input
voltage, with a specified “turns ratio” or voltage ratio, plus
minor drop from the internal resistive losses in the module.
When used in IBA systems, the output variation of the
BusQor must be in accordance with the input voltage range
of the non-isolated converters being employed.
Typical User Board
2.5 V
48Vdc
35-55V
48Vdc
Front
End
3.3 V
BusQor
12 Vdc
Converter
1.8 V
1.5 V
0.9 V
NiQor
Loads
Converters
Figure A: Example of Intermediate Bus Architecture using BusQor bus
converter and NiQor non-isolated converters
Product # BQ55120QEx50
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Doc.# 005-0005571 Rev. F
10/03/11
Page 10
Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Application Section
PROTECTION FEATURES
Input Under-Voltage Lockout:The converter is
designed to turn off when the input voltage is too
low, helping avoid an input system instability problem,
described in more detail in the application note titled
“Input System Instability”. The lockout circuitry is a
comparator with DC hysteresis. When the input voltage
is rising, it must exceed the typical Turn-On Voltage
Threshold value (listed on the specification page) before
the converter will turn on. Once the converter is on, the
input voltage must fall below the typical Turn-Off Voltage
Threshold value before the converter will turn off. Also see
Figure E.
Output Current Limit: The output of the BusQor module
is electronically protected against output overloads. When
an overload current greater than the “DC Current-Limit
Inception” specification is drawn from the output, the
output shuts down to zero volt in a period of 20ms typical
(see Figure D). The shutdown period lasts for a typical
period of 200ms (Figure D) after which the BusQor tries
to power up again. If the overload persists, the output
voltage will go through repeated cycles of shutdown and
restart with a duty cycle of 10% (On) and 90% (Off)
respectively. The BusQor module returns (auto resetting)
to normal operation once the overload is removed. The
BusQor is designed to survive in this mode indefinitely
without damage and without human intervention.
Output
Current
60A
50A
Output
Voltage
<12V
0V
Time
1ms
100A
peak
Output
Current
Output
Voltage
<12V
0V
220ms
20ms
Time
Figure D: Output Short Circuit and Auto-Resetting protection diagram (not
to scale)
Output Short Circuit Protection: When the output of
the BusQor module is shorted, a peak current of typically
100 A will flow into the short circuit for a period of about
20ms. The output of the BusQor will shutdown to zero
for ~ 200mS (Figure D). At the end of the shutdown
period the BusQor module tries to power up again. If the
short circuit persists, the output voltage will go through
repeated cycles of shutdown and restart with a duty cycle
of 10% (On) and 90% (Off) respectively. The BusQor
module returns (auto resetting) to normal operation once
the short circuit is removed. The BusQor is designed
to survive in this mode indefinitely without damage and
without human intervention.
In the Auto resetting mode, also referred to as “Hiccup”
mode, the power drawn from the 48V input is about 5
Watts, most of which is dissipated into the external fault.
It is important that copper traces and pads from the
output circuit be designed to withstand the short term
peaks, although the average current into the fault may
be as low as 8A typical. See Figure 18 for appropriate
waveform.
Over-Temperature Shutdown: A temperature sensor
on the converter senses the average temperature of the
module. The thermal shutdown circuit is designed to turn
the converter off when the temperature at the sensed
location reaches the Over-Temperature Shutdown value.
It will allow the converter to turn on again when the
temperature of the sensed location falls by the amount of
the Over-Temperature Shutdown Restart Hysteresis value.
Figure C: Output Overload protection diagram (not to scale)
Product # BQ55120QEx50
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Doc.# 005-0005571 Rev. F
10/03/11
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Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Application Section
APPLICATION CONSIDERATIONS
0.01”
Start-Up Inhibit Period: Figure E details the Start-Up Inhibit Period
for the BusQor module. At time t0, when Vin is applied with On/Off pin
asserted (enabled), the BusQor output begins to build up. Before time t1,
when the input voltage is below the UVL threshold, the unit is disabled
by the Input Under-Voltage Lockout feature. When the input voltage rises
above the UVL threshold, the Input Under-Voltage Lockout is released, and
a typical Startup Inhibit Period of 12ms is initiated. The output builds up to
90% of the nominal value of 12V in a period of 15ms typical (50 % load).
0.023”
At time t2, when the On/Off pin is de-asserted (disabled), the BusQor
output instantly drops to 0V. Fall time from 12V to 0V is dependent on
output capacitance and any parasitic trace inductance in the output load
circuit.
At time t3, when the On/Off pin is re-asserted (enabled), the BusQor
module output begins to build up after the inhibit period of 200 ms typical
has elapsed.
Vin
1.50”
Primary
Secondary
Figure F: Keep Out Areas for BusQor module
UVLO
Bridging Components: Bridging components like EMI filter capacitors
required to be placed as close as possible to the BusQor module for
optimum performance must observe the clearance/creepage requirements
of 0.04”(40 mils) between pads to maintain compliance to UL standards for
the overall power system.
On/Off
(N logic)
OFF
ON
t0
Vout
Bridging
Capacitor
0.01”
t1
t2
t3
t
Note: Referenced keep out widths are adequate to withstand UL’s Basic
Insulation Dielectric strength tests for approved PCB materials. Applications
requiring Double or Reinforced insulation must double the keep out widths
shown in Figure F. Keep out areas shown have standard margins above
UL’s minimum requirements.
12V
200ms
12ms
Time
215ms
Figure E: Power Up/Down Diagram (not to scale) showing Start-Up Inhibit
Period
Refer to the Control Features section of the data sheet for details on
enabling and disabling methods for N and P logic type modules.
Component Keep Out Area: Keep out areas for components not
referenced to the Primary circuit are shown in shaded areas in Figure F.
The keep out areas shown are consistent with UL’s requirements for Basic
Insulation of 0.04” (40 mils) for Pollution degree 2. User should consult UL
standards for other insulation classes and operating environments.
For applications that require mounting parts BELOW the BusQor
module, one should be aware of potential high levels of electromagnetic
interference, in addition to safety keep out. Users are advised to consult
SynQor Applications engineering in such applications.
Copper Keep Out Area: Keep out areas shown in Figure F are to be
observed for Top layer copper traces and vias. Internal layers buried one
or more layers may be exempt, depending on the PCB material grade and
thickness. Users are advised to consult UL standards for details.
All layers including top and bottom, are subject to the keep out areas
shown around Primary pins of BusQor module. Actual keep outs along the
surface (Creepage) may vary depending on the PCB material CTI. Users
are advised to consult UL standards for details.
Product # BQ55120QEx50
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Figure G: Location of Sense Resistor
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Doc.# 005-0005571 Rev. F
10/03/11
Page 12
Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Application Section
where:
Iload = output load current
VRsense(no load) = voltage across the sense resistor with converter at
zero load
The number 2000 is a “Load Current Scale Factor” for this product, valid
only for Vin = 48V. Hence, measurement should be made at this input
voltage.
+
1
Vin
2
3
2
3
4.0%
3.0%
2.0%
1.0%
0.0%
-1.0%
-2.0%
-3.0%
Module 1
Module 2
-4.0%
-5.0%
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
Total Load Current (A)
Figure I: Current share performance of 2 paralleled modules
+
BusQor
module
(N logic
option)
5
Current Sharing: BusQor modules are designed to operate in parallel
without the use of any external current share circuitry. A typical circuit for
paralleling two BusQor modules is shown in Figure H. An output capacitor
12Vout is recommended across each module and located close to the converter
50A
for optimum filtering and noise control performance. Dedicated input
inductors are recommended but are considered optional. Input capacitors
must be located close to the converter module. PCB layout in the input
circuit should be such that high frequency ripple currents of each module is
—
restricted to a loop formed by the input capacitors and the input terminals
of the BusQor module. See Figure J for details on PCB layout. Contact
SynQor application engineering for further assistance on PCB trace design.
4
The current share performance of two paralleled modules is illustrated in
the graph in Figure I. In this graph the percent deviation from ideal sharing
(50%) is plotted for each module versus the total output load current at
48Vin.
5
4
—
1
5.0%
Deviation from 50/50 Sharing (%)
Output Load Current Calculation: The BusQor series allows the
converter output load to be measured without adding a current loop or
external shunt resistor to the designer’s PCB board under test. On the top
side of the BusQor converter is a current sense resistor as shown in Figure
G. The output load current is proportional to the voltage drop across this
sense resistor. This calculation is detailed below. A current sense resistor
referenced to the primary input is used in the equation below to calculate
the output load current.
Iload = (VRsense(load) - VRsense(no load) ) x 2000
BusQor
module
(N logic
option)
Figure H: BusQor Output Paralleling for increased current output
The voltage drop across the sense resistor is about 25 mV at full load of 50 A.
Therefore, proper measuring techniques must be used to ensure accuracy.
A calibrated DMM set to 300mV is acceptable. Since this measurement is
done on the Primary area of the converter, a slight non-linearity may be
observed over the load current range. Measurements should be made at 48
V input voltage. Using the Scale Factor referenced above, the error may be
on the order of 4%. For more detailed information consult the application
note on SynQor’s website titled “Output Load Current Calculations”.
BusQor module
48Vin
CM EMI
filter
(Not shown
in Figure H)
Bulk
Cap
BusQor module
Input LC filters
Figure J: Recommended PCB layout for input circuit
Product # BQ55120QEx50
Phone 1-888-567-9596
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Doc.# 005-0005571 Rev. F
10/03/11
Page 13
Input:35-55V
Output:12.0V
Current:50A
Part No.:BQ55120QEx50
Ordering Section
PART NUMBERING SYSTEM
ORDERING INFORMATION
The part numbering system for SynQor’s dc-dc converters
follows the format shown in the example below.
The tables below show the valid model numbers and ordering
options for converters in this product family. When ordering
SynQor converters, please ensure that you use the complete
15 character part number consisting of the 12 character
base part number and the additional characters for options.
Add “-G” to the model number for 6/6 RoHS compliance.
BQ 5 5 1 2 0 Q E A 5 0 N R S - G
6/6 RoHS
Options
(see
Ordering Information)
Output Current
Model Number
BQ55120QEw50xyz-G
Input
Voltage
35-55V
Output
Voltage
12.0V
Max Output
Current
50A
Thermal Design
Performance Level
The following options must be included in place of the w x y z
spaces in the model numbers listed above.
Package Size
Output Voltage
Options Description: w x y z
Input Voltage
Product Family
The first 12 characters comprise the base part number and
the last 3 characters indicate available options. The “-G”
suffix indicates 6/6 RoHS compliance.
Application Notes
A variety of application notes and technical white papers can
be downloaded in pdf format from our website.
RoHS Compliance: The EU led RoHS (Restriction of Hazardous
Substances) Directive bans the use of Lead, Cadmium,
Hexavalent Chromium, Mercury, Polybrominated Biphenyls
(PBB), and Polybrominated Diphenyl Ether (PBDE) in Electrical
and Electronic Equipment. This SynQor product is 6/6 RoHS
compliant. For more information please refer to SynQor’s
RoHS addendum available at our RoHS Compliance / Lead Free
Initiative web page or e-mail us at [email protected].
Thermal Design
Enable Logic
Pin Style
Feature Set
A - Open Frame
B - Baseplated
N - Negative
P - Positive
K - 0.110"
N - 0.145"
R - 0.180"
Y - 0.250"
S - Standard
Not all combinations make valid part numbers, please contact
SynQor for availability. See the Product Summary web page for
more options.
PATENTS
SynQor holds the following U.S. patents, one or more of which apply to
each product listed in this document. Additional patent applications may
be pending or filed in the future.
5,999,417
6,222,742
6,545,890
6,577,109
6,594,159
6,731,520
6,894,468
6,896,526
6,927,987
7,050,309
7,072,190
7,085,146
7,119,524
7,269,034
7,272,021
7,272,023
7,558,083
7,564,702
7,765,687
7,787,261
8,023,290
Contact SynQor for further information:
Phone:
Toll Free:
Fax:
E-mail:
Web:
Address:
Product # BQ55120QEx50
978-849-0600
888-567-9596
978-849-0602
[email protected]
www.synqor.com
155 Swanson Road
Boxborough, MA 01719
USA
Phone 1-888-567-9596
Warranty
SynQor offers a three (3) year limited warranty. Complete warranty information is listed on our website or is available upon request from SynQor.
Information furnished by SynQor is believed to be accurate and reliable.
However, no responsibility is assumed by SynQor for its use, nor for any
infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any
patent or patent rights of SynQor.
www.synqor.com
Doc.# 005-0005571 Rev. F
10/03/11
Page 14