20A [175W - 275W]

Technical
Specification
BQ55120ETx20
35-55 V
12 V
20 A
Input
Output
Current
240 Watt 2000 Vdc
Power
Isolation
Eighth-brick
DC Bus Converter
®
The BusQor® BQ55120ETx20 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 heat sink is not required, which saves cost,
weight, height, and application effort. The BusQor
series provides an isolated step down voltage from 3555 V to a 12 V intermediate bus with no regulation in a
standard “eighth-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. RoHS Compliant (see last page).
BQ55120ETA20 Model
Operational Features
Mechanical Features
• Ultra-high efficiency, >95.5% at full rated load current
• Delivers up to 20 amps of output current (240 W) with
minimal derating - no heat sink required
• Input voltage range: 35 – 55 V provides 12 V bus for
distributed power architectures
• Fixed frequency switching provides predictable EMI performance
•
•
•
•
Industry standard eighth-brick bus converter pin-out
Size: 0.90" x 2.3" (22.9x58.4mm) x 0.484" (12.29mm)
Total weight: 0.7 oz. (20 grams)
Encased Size: 0.99” x 2.39” (25x 60.6 mm)0.496” (12.6 mm)
Protection Features
• Input under-voltage lockout and over-voltage shutdown protects
against abnormal input voltages
• Output current limit and short circuit protection
• Thermal shutdown
Control Features
• On/Off control referenced to input side
(positive and negative logic options are available)
Contents
Page No.
Safety Features
• UL 60950-1:2007/R:2011-12
• EN 60950-1:2006/A2:2013
• CAN/CSA C22.2 No. 60950-1:2007/A1:2011
Product # BQ55120ETx20
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Open Frame Mechanical Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Encased Mechanical Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Compliance & Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Technical Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Applications Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
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Doc.# 005-2BE553B Rev. G
04/04/16
Page 1
Open Frame Mechanical Diagram
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
NOTES
PIN DESIGNATIONS
1) PINS 1-3 ARE 0.040" (1.02MM) DIA. WITH 0.080"
(2.03mm) DIA. STANDOFF SHOULDERS
2) PINS 4-5, ARE 0.062" (1.57mm) DIA. WITH 0.100"
(2.54mm) DIA. STANDOFF SHOULDERS
3) OTHER PIN EXTENSION LENGTHS AVAILABLE
4) ALL PINS: MATERIAL: COPPER ALLOY
FINISH: TIN-LEAD OVER NICKEL PLATE
5) UNDIMENSIONED COMPONENTS ARE SHOWN FOR
VISUAL REFERENCE ONLY
6) ALL DIMENSIONS IN INCHES (mm)
TOLERANCES: X.XXIN +/- 0.02 (X.Xmm +/- 0.5mm)
X.XXXIN +/- 0.010 (X.XXmm =/- 0.25mm)
7)WEIGHT: 0.7 oz. (20 grams)
8)WORKSMANSHIP: MEETS OR EXCEEDS IPC-A-610C CLASS II
9)UL/TUV STANDARDS REQUIRE A CLEARANCE OF 0.04" (1.02mm)
Pin Name
Function
1 Vin(+) Input positive (35V - 55V)
2 ON/OFF Logic control input to turn
converter on and off
3 Vin(–) Input Negative
4 Vout(–) Output Negative
5 Vout(+) Output Positive
AROUND PRIMARY AREAS OF THE MODULE. REFER TO SECTION ON
KEEP OUT AREAS UNDER APPLICATION CONSIDERATIONS FOR
DETAILS
10)THE FLANGED PINS ARE DESIGNED TO PERMIT SURFACE MOUNT
SOLDERING
Product # BQ55120ETx20
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Doc.#005-2BE553B Rev. G
04/04/16
Page 2
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
Encased Mechanical Diagram
0.99 (25)
0.496 ±0.025
0.600 (15.24)
(12.6 ±0.63)
Overall height
5
4
Side
View
Top View
2.39
(60.6)
2.00
(50.8)
0.18
(4.6)
0.145
1
2
(3.68)
See Note 3
3
0.19 (4.9)
0.300 (7.62)
0.600 (15.24)
PIN DESIGNATIONS
NOTES
1) Pins 1-3 are 0.040" (1.02mm) dia. with 0.080" (2.03mm) dia.
standoff shoulders.
2) Pins 4 and 5 are 0.062" (1.57mm) dia. with 0.100" (2.54mm) dia.
standoff shoulders
3) Other pin extension 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.xxin +/-0.02 (x.xmm +/-0.5mm)
x.xxxin +/-0.010 (x.xxmm +/-0.25mm)
7) Weight: 1.9 oz. (55.2g) typical
8) Workmanship: Meets or exceeds IPC-A-610C Class II
9) Baseplate tolerance is 0.004" (0.10mm) TIR for surface.
Product # BQ55120ETx20
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Pin Name
Function
1 Vin(+) Input positive (35V - 55V)
2 ON/OFF Logic control input to turn
converter on and off
3 Vin(–) Input Negative
4 Vout(–) Output Negative
5 Vout(+) Output Positive
www.synqor.com
Doc.#005-2BE553B Rev. G
04/04/16
Page 3
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
Technical Specification
BQ55120ETx20 Electrical Characteristics
Ta = 25 °C, airflow rate = 300 LFM, Vin = 48 V 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.
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
Inrush Current Transient Rating
Input Reflected Ripple Current
Input Terminal Ripple Current
Recommended Input Fuse
Input Filter Component Values (L\C)
Recommended External Input Capacitance
OUTPUT CHARACTERISTICS
Output Voltage Set Point
Output Voltage Regulation
Over Line
Over Load
Over Temperature
Total Output Voltage Range
Output Voltage Ripple and Noise1
Peak-to-Peak
RMS
Operating Output Current Range
Output DC Current-Limit Inception
Output DC Current-Limit Shutdown Voltage
Current Share Accuracy (2 units paralleled)
Back-Drive Current Limit while Disabled
Maximum Output Capacitance
EFFICIENCY
100% Load
50% Load
Typ.
-1
-40
-45
-2
35
48
Max.
60
56
2000
100
125
18
V
V
V
°C
°C
V
55
V
32.0
30.5
1.5
58
59
7
10
50
Units Notes & Conditions
5.5
0.1
15
0.1
V
V
V
V
V
V
A
A
mA
A2s
mA
mA
A
µH\µF
Continuous
Continuous
Basic insulation, Pollution Degree 2
On Open Frame model
100% Load, 35 Vin
µF
RMS through 10 µH inductor; Figures 12 & 14
RMS, full load; Figures 12 & 13
Fast blow external fuse recommended
Internal values
Typical ESR 0.1-0.2 Ω, see Figure 12
12.00
V
48 Vin, no load
±20 \ 2.4
±4.1 \ 500
±1.7 \ 200
13.8
%\V
%\mV
%\mV
V
150
40
20
mV
mV
A
3,000
A
V
%
mA
µF
100
12
1.5\2.0
47
8.0
100
20
0
27
Vin / 8
±10
10
95.5
96.0
%
%
Figure 4
Figure 4
Figure 4
Over sample, line, load, temperature & life
20 MHz bandwidth; Figures 12 & 15
Full Load, see Figures 12 & 15
Full Load, see Figures 12 & 15
Subject to thermal derating; Figures 5 - 8
Output Voltage 10% Low; Figure 16
% of rated output current
Negative current drawn from output
12 Vout at 20 A Resistive Load
Figures 1 & 3
Figures 1 & 3
Note 1: For applications requiring reduced output voltage ripple and noise, consult SynQor applications support (e-mail: [email protected]).
Product # BQ55120ETx20
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Doc.# 005-2BE553B Rev. G
04/04/16
Page 4
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
Technical Specification
BQ55120ETx20 Electrical Characteristics (continued)
Ta = 25 °C, airflow rate = 300 LFM, Vin = 48 V 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.
DYNAMIC CHARACTERISTICS
Output Voltage during Load Current Transient
For a Step Change in Output Current (0.1 A/µs)
Settling Time
Turn-On Transient
Turn-On Time
Fault Inhibit Time
Output Voltage Overshoot
TEMPERATURE LIMITS FOR POWER
Semiconductor Junction Temperature
Board Temperature
Transformer Temperature
ISOLATION CHARACTERISTICS
Isolation Voltage (dielectric strength)
Isolation Resistance
Isolation Capacitance (input to output)
FEATURE CHARACTERISTICS
Switching Frequency
ON/OFF Control (Option P)
Off-State Voltage
On-State Voltage
ON/OFF Control (Option N)
Off-State Voltage
On-State Voltage
ON/OFF Control (Either Option)
Pull-Up Voltage
Pull-Up Resistance
Over-Temperature Shutdown
Over-Temperature Shutdown Restart Hysteresis
Load Current Scale Factor
RELIABILITY CHARACTERISTICS
Calculated MTBF (Telcordia)
Calculated MTBF (MIL-217)
Field Demonstrated MTBF
Product # BQ55120ETx20
Typ.
Max.
200
200
mV
µs
50% to 75% to 50% Iout max; Figure 11
To within 1% Vout nom
9
250
0
ms
ms
%
Full load, Vout = 90% nom.; Figures 9 & 10
Figure E
2,500 μF load capacitance, Iout = 0 A
°C
°C
°C
Package rated to 150 °C
UL rated max operating temp 130 °C
See Figures 5 - 8 for derating curves
125
125
125
2000
30
470
165
Units Notes & Conditions
190
V
MΩ
pF
215
kHz
-1.0
2.4
0.8
18
V
V
2.4
-1.0
18
0.8
V
V
See Figure B
10
30
140
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150
10
667
2.36
1.79
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V
kΩ
°C
°C
Average PCB Temperature
See App Note: Output Load Current Calc.
106 Hrs. TR-NWT-000332; 80% load, 300 LFM, 40 °C Ta
106 Hrs. MIL-HDBK-217F; 80% load, 300 LFM, 40 °C Ta
106 Hrs. See our website for details
Doc.# 005-2BE553B Rev. G
04/04/16
Page 5
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
Technical Specification
Compliance & Testing
Parameter
Notes & Conditions
STANDARDS COMPLIANCE
UL 60950-1:2007/R:2011-12
Basic insulation
EN 60950-1:2006/A2:2013
CAN/CSA C22.2 No. 60950-1:2007/A1:2011
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 # BQ55120ETx20
# 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, 95% RH, 1000 hours, continuous Vin applied except 5 min/day
MIL-STD-883, method 2003
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Doc.# 005-2BE553B Rev. G
04/04/16
Page 6
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
Technical Figures
11
100
10
9
Power Dissipation (W)
Efficiency (%)
95
90
85
80
35 Vin
48 Vin
55 Vin
75
70
8
7
6
5
4
3
35 Vin
2
48 Vin
1
55 Vin
0
0
4
8
12
16
20
0
4
8
Load Current (A)
12
16
20
Load Current (A)
Figure 1: Efficiency at nominal output voltage vs. load current for minimum,
nominal, and maximum input voltage at 25 °C.
Figure 2: Power dissipation at nominal output voltage vs. load current
for minimum, nominal, and maximum input voltage at 25 °C.
97
14
13
12
Output Voltage (V)
Efficiency (%)
96
95
94
25 C
40 C
55 C
93
100
200
300
11
10
9
8
35V
48V
7
6
400
0
2
4
6
8
10
12
14
16
18
20
Load Current (A)
Air Flow (LFM)
Figure 3: 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).
55V
Figure 4: Output voltage regulation vs. load current for minimum, nominal, and
maximum input voltage at 25 °C.
20
Iout (A)
16
12
8
400
300
200
100
4
LFM (2.0
LFM (1.5
LFM (1.0
LFM (0.5
m/s)
m/s)
m/s)
m/s)
0
0
25
40
55
70
Semiconductor junction temperature is
within 1°C of surface temperature
85
Ambient Air Temperature (ºC)
Figure 5: Maximum output power derating curves vs. ambient air temperature
for airflow rates of 100 LFM through 400 LFM with air flowing from pin 3 to pin
1 (nominal input voltage).
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Figure 6: Thermal plot of converter at 20 amp load current (240 W)
with 55 °C air flowing at the rate of 200 LFM. Air is flowing across the
converter from pin 3 to pin 1 (nominal input voltage).
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Doc.#005-2BE553B Rev. G
04/04/16
Page 7
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
Technical Figures
20
Iout (A)
16
12
8
400
300
200
100
4
LFM (2.0
LFM (1.5
LFM (1.0
LFM (0.5
m/s)
m/s)
m/s)
m/s)
0
0
25
40
55
70
85
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 from output to
input (nominal input voltage).
Figure 8: Thermal plot of converter at 20 amp load current (240 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 half load (resistive load) and 3 mF output
capacitance (2.0 ms/div). Input voltage pre-applied. Channel 1: Vout
(2 V/div). Channel 2: ON/OFF input (2 V/div).
Figure 10: Turn-on transient at zero load and 3 mF output capacitance (2.0 ms/
div). Input voltage pre-applied. Channel 1: Vout (2 V/div). Channel 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 = 0.1 A/μ s). Load cap: 15 μ F, 100 mΩ ESR tantalum
cap and 1 μ F ceramic cap. Top trace: Vout (200 mV/div), Bottom trace: Iout (5
A/div).
Figure 12: Test set-up diagram showing measurement points for Input
Terminal Ripple Current (Figure 13), Input Reflected Ripple Current
(Figure 14) and Output Voltage Ripple (Figure 15)
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04/04/16
Page 8
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
Technical Figures
Figure 13: Input Terminal Ripple Current, ic, at full rated output current
and nominal input voltage with 10 μ H source impedance and 47 μ F
electrolytic capacitor (50 mA [200 mV]/div). See Figure 12.
Figure 14: Input reflected ripple current, is, through a 10 μ H source
inductor at nominal input voltage and rated load current (5 mA
[10 mV]/div). See Figure 12.
14
Output Voltage (V)
12
10
8
6
4
35V
48V
2
0
55V
0
5
10
15
20
25
30
Load Current (A)
Figure 15: Output voltage ripple at nominal input voltage and rated
load current (50 mV/div). Load capacitance: 1 μ F ceramic capacitor
and 15 μ F tantalum capacitor. Bandwidth: 20 MHz. See Figure 12.
Figure 16: Output voltage vs. load current showing typical current limit
curves and converter shutdown points.
1
35 Vin
Output Impedance (ohms)
48 Vin
55 Vin
0.1
0.01
10
100
1,000
10,000
100,000
Hz
Figure 17: Load current (10 A/div) as a function of time when the converter
attempts to turn on into a 1 mΩ short circuit. Top trace (5.0 ms/div) is an
expansion of the on-time portion of the bottom trace.
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Figure 18: Magnitude of incremental output impedance (Zout = vout/iout) for
minimum, nominal, and maximum input voltage at full rated power.
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Doc.#005-2BE553B Rev. G
04/04/16
Page 9
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
10
10
0
0
Reverse Transmission (dB)
Forward Transmission (dB)
Technical Figures
-10
-20
35 Vin
-30
48 Vin
-10
-20
35 Vin
-30
48 Vin
55 Vin
-40
10
55 Vin
100
1,000
10,000
-40
100,000
Hz
10
100
1,000
10,000
100,000
Hz
Figure 19: Magnitude of incremental forward transmission (FT = vout/vin)
for minimum, nominal, and maximum input voltage at full rated power.
Figure 20: Magnitude of incremental reverse transmission (RT = iin/iout)
for minimum, nominal, and maximum input voltage at full rated power.
10000
Input Impedance (ohms)
1000
100
10
35 Vin
1
48 Vin
55 Vin
0.1
10
100
1,000
10,000
100,000
Hz
Figure 21: Magnitude of incremental input impedance (Zin = vin/iin)
for minimum, nominal, and maximum input voltage at full rated power.
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Doc.#005-2BE553B Rev. G
04/04/16
Page 10
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
Applications 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 a coarse 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 point of load. In this case, the bucks are
represented with SynQor’s NiQor series of non-isolated dc/dc
converters. In many applications requiring multiple low voltage
outputs, significant savings can be achieved in board space
and overall system costs.
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(+)
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: 12 V, 9 V, 7.5 V, 5 V, or 3.3 V. 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.
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.
On/Off
5V
124K
5V
49.9K
TTL
100k
Vin(-)
Figure B: Internal ON/OFF pin circuitry
The BusQor architecture is very scalable, meaning multiple bus
converters can be connected directly in parallel to allow current
sharing for higher power applications.
3.3 V
Front End
48 Vdc
35-55 V
BusQor
Converter
12 Vdc
2.5 V
1.8 V
1.5 V
0.9 V
Typical User Board
Converters
Loads
Figure A: Example of Intermediate Bus Architecture using BusQor bus converter
and NiQor non-isolated converters
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Doc.#005-2BE553B Rev. G
04/04/16
Page 11
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
Applications 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 TurnOn 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.
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 1 ms typical (see
Figure C). The shutdown period lasts for a typical period of
250 ms (Figure D) after which the BusQor tries to power up
again (20ms). If the overload persists, the output voltage
will go through repeated cycles of shutdown and restart with
a duty cycle of 4 % (On) and 96 % (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
27 A
20 A
Output
Voltage
12 V
0V
Time
1 ms
Figure C: Output Overload protection diagram (not to scale)
Product # BQ55120ETx20
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Output
Current
42 A
peak
Output
Voltage
< 12 V
0V
Time
250 ms
10 ms
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
42 A will flow into the short circuit for a period of about
10 ms. The output of the BusQor will shutdown to zero for
~ 250 ms (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 4 %
(On) and 96 % (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 48 V 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 input current into the fault may be as
low as 0.1 A typical. See Figure 17 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.
www.synqor.com
Doc.#005-2BE553B Rev. G
04/04/16
Page 12
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
Applications Section
APPLICATION CONSIDERATIONS
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 3 ms is initiated. The output
builds up to 90% of the nominal value of 12 V in a period of 1.5 ms typical.
Figure F: Keep Out Areas for BusQor module
At time t2, when the On/Off pin is de-asserted (disabled), the BusQor output
instantly drops to 0V. Fall time from 12 V to 0 V 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 3 ms typical has elapsed.
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.
Vin
UVLO
On/Off
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.
(N logic)
OFF
ON
t0
t1
t2
t3
Vout
t
Vin
Start-up
Inhibit
Fault Inhibit
Time
Start-Up
Figure E: Power Up/Down Diagram (not to scale) showing Start-Up Inhibit
Period
Product # BQ55120ETx20
Phone 1-888-567-9596
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.
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.
www.synqor.com
Doc.#005-2BE553B Rev. G
04/04/16
Page 13
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
Applications Section
5.0%
Figure G: Location of Sense Resistor
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 667
where:
Iload = output load current
VRsense(load) = voltage across the sense resistor with converter under
load
VRsense(no load) = voltage across the sense resistor with converter at
zero load
The number 667 is a “Load Current Scale Factor” for this product, valid only
for Vin = 48 V. Hence, measurement should be made at this input voltage.
The voltage drop across the sense resistor is about 30 mV at full load
of 20 A. Therefore, proper measuring techniques must be used to
ensure accuracy. A calibrated DMM set to 300 mV 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”.
+
1
Vin
2
3
3.0%
2.0%
1.0%
0.0%
-1.0%
-2.0%
-3.0%
Module 1
-4.0%
-5.0%
Module 2
5
10
15
20
25
30
35
Figure I: Current share performance of 2 paralleled modules
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
is recommended across each module and located close to the converter 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.
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
48 Vin.
+
BusQor
module
(N logic
option)
12 Vout
40 A
4
48 Vin
BusQor module
—
1
2
3
40
Total Load Current (A)
5
—
BusQor
module
(N logic
option)
CM EMI
filter
5
(Not shown
in Figure H)
Bulk
Cap
BusQor module
4
Figure H: BusQor Output Paralleling for increased current output
Product # BQ55120ETx20
Deviation from 50/50 Sharing (%)
4.0%
Phone 1-888-567-9596
Input LC filters
Figure J: Recommended PCB layout for input circuit
www.synqor.com
Doc.#005-2BE553B Rev. G
04/04/16
Page 14
Input: 35-55 V
Output: 12 V
Current: 20 A
Package: Eighth-brick
Ordering Information
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 E T A 2 0 N N S - G
6/6 RoHS
Options
(see
Ordering Information)
Model Number
Input Voltage
BQ55120ETw20xyz-G
35-55 V
Output
Voltage
12 V
Max Output
Current
20 A
Output Current
Thermal Design
Performance Level
Package Size
The following options must be included in place of the w x y z spaces in the
model numbers listed above.
Output Voltage
Input Voltage
Thermal
Design
Product Family
A - Open Frame
C - Encased
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.
Options Description: w x y z
Enable
Logic *
Pin
Length
Feature
Set
P - Positive
N - Negative
K - 0.110"
N - 0.145"
R - 0.180"
Y - 0.250"
S - Standard
* Consult the factory before ordering the P logic option
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].
Not all combinations make valid part numbers, please contact SynQor for
availability.
Contact SynQor for further information and to order:
PATENTS
Phone:
Toll Free:
Fax:
E-mail:
Web:
Address:
Product # BQ55120ETx20
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
SynQor holds numerous U.S. patents, one or more of which apply to most of its power converter
products. Any that apply to the product(s) listed in this document are identified by markings on
the product(s) or on internal components of the product(s) in accordance with U.S. patent laws.
SynQor’s patents include the following:
5,999,417
6,222,742
6,545,890
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
8,149,597
8,493,751
8,644,027
9,143,042
WARRANTY
SynQor offers a three (3) year limited warranty. Complete warranty
information is listed on our website or is available upon request from SynQor.
www.synqor.com
Doc.#005-2BE553B Rev. G
04/04/16
Page 15