SYNQOR MQFL-28-2R5S

MQFL-28-2R5S
Single Output
H igh R eliability DC/DC C onverter
16-40V
Continuous Input
16-50V
Transient Input
2.5V
40A
Output
88% @ 20A / 87% @ 40A
Output
F ull P ower O peration : -55ºC
to
Efficiency
+125ºC
The MilQor® series of high-reliability DC/DC converters
brings SynQor’s field proven high-efficiency synchronous
rectifier technology to the Military/Aerospace industry.
SynQor’s innovative QorSealTM packaging approach ensures
survivability in the most hostile environments. Compatible
with the industry standard format, these converters operate
at a fixed frequency, have no opto-isolators, and follow
conservative component derating guidelines. They are
designed and manufactured to comply with a wide range of
military standards.
Design Process
Designed & Manufactured in the USA
Featuring QorSeal™ Hi-Rel Assembly
MQFL series converters are:
• Designed for reliability per NAVSO-P3641-A guidelines
• Designed with components derated per:
— MIL-HDBK-1547A
— NAVSO P-3641A
Qualification Process
MQFL series converters are qualified to:
• MIL-STD-810F
— consistent with RTCA/D0-160E
• SynQor’s First Article Qualification
— consistent with MIL-STD-883F
• SynQor’s Long-Term Storage Survivability Qualification
• SynQor’s on-going life test
Features
•
•
•
•
•
•
•
•
Fixed switching frequency
No opto-isolators
Parallel operation with current share
Remote sense
Clock synchronization
Primary and secondary referenced enable
Continuous short circuit and overload protection
Input under-voltage lockout/over-voltage shutdown
Specification Compliance
In-Line Manufacturing Process
•
•
•
•
•
•
AS9100 and ISO 9001:2000 certified facility
Full component traceability
Temperature cycling
Constant acceleration
24, 96, 160 hour burn-in
Three level temperature screening
Product # MQFL-28-2R5S
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MQFL series converters (with MQME filter) are designed to meet:
• MIL-HDBK-704-8 (A through F)
• RTCA/DO-160E Section 16
• MIL-STD-1275B
• DEF-STAN 61-5 (part 6)/5
• MIL-STD-461 (C, D, E)
• RTCA/DO-160E Section 22
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Doc.# 005-2MQ250S Rev. B
03/19/09
Page 1
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
BLOCK DIAGRAM
TYPICAL CONNECTION DIAGRAM
1
2
3
4
28Vdc +
–
5
open
means
on
Product # MQFL-28-2R5S
6
ENA 2
+VIN
IN RTN
SHARE
CASE
+ SNS
ENA 1
– SNS
SYNC OUT
OUT RTN
+VOUT
SYNC IN
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12
11
open
means
on
10
9
+
Load
8
–
7
Doc.# 005-2MQ250S Rev. B
03/19/09
Page 2
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
MQFL-28-2R5S ELECTRICAL CHARACTERISTICS
Parameter
Min. Nom.
Max. Units Notes & Conditions
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Non-Operating
Operating 1
Reverse Bias (Tcase = 125ºC)
Reverse Bias (Tcase = -55ºC)
Isolation Voltage (input/output to case, input to output)
Continuous
-500
Transient (≤100 µs)
-800
Operating Case Temperature 2
-55
Storage Case Temperature
-65
Lead Temperature (20 sec)
Voltage at ENA1, ENA2, SYNC IN
-1.2
INPUT CHARACTERISTICS
Operating Input Voltage Range (continuous)
16
28
Operating Input Voltage Range (transient, 1 sec)
16
28
Input Under-Voltage Lockout 3
Turn-On Voltage Threshold
14.75
15.50
Turn-Off Voltage Threshold
13.80
14.40
Lockout Voltage Hysteresis
0.50
1.10
Input Over-Voltage Shutdown 3
Turn-Off Voltage Threshold
54.0
56.8
Turn-On Voltage Threshold
50.0
51.4
Shutdown Voltage Hysteresis
2.0
5.3
Maximum Input Current
No Load Input Current (operating)
110
Disabled Input Current (ENA1)
2
Disabled Input Current (ENA2)
25
Input Terminal Current Ripple (peak to peak)
40
OUTPUT CHARACTERISTICS
60
60
-0.8
-1.2
V
V
V
V
500
800
135
135
300
50
V
V
°C
°C
°C
V
40
50
V
V
1, 2, 3
4, 5, 6
16.00
15.00
1.80
V
V
V
1, 2, 3
1, 2, 3
1, 2, 3
60.0
54.0
8.0
8
160
5
50
60
Output Voltage Set Point (Tcase = 25ºC)
2.47
2.50
2.53
Output Voltage Set Point Over Temperature
2.46
2.50
2.54
Output Voltage Line Regulation
-20
0
20
Output Voltage Load Regulation
7
12
17
Total Output Voltage Range
2.45
2.50
2.55
Output Voltage Ripple and Noise Peak to Peak
15
60
Operating Output Current Range
0
40
Operating Output Power Range
0
100
Output DC Current-Limit Inception 4
41
46
52
Short Circuit Output Current
41
47
53
Back-Drive Current Limit while Enabled
13
Back-Drive Current Limit while Disabled
10
50
Maximum Output Capacitance
10,000
DYNAMIC CHARACTERISTICS
Output Voltage Deviation Load Transient 6
For a Positive Step Change in Load Current
-450
-300
For a Negative Step Change in Load Current
300
450
Settling Time (either case) 7
200
350
Output Voltage Deviation Line Transient 8
For a Positive Step Change in Line Voltage -250
250
For a Negative Step Change in Line Voltage -250
250
7
Settling Time (either case) 250
500
Turn-On Transient
Output Voltage Rise Time
6
10
Output Voltage Overshoot
0
2
Turn-On Delay, Rising Vin 9 11
5.5
8.0
Turn-On Delay, Rising ENA1 11
3.0
6.0
Turn-On Delay, Rising ENA2 11
1.5
3.0
EFFICIENCY
Iout = 40A (16Vin)
82
Iout = 20A (16Vin)
86
Iout = 40A (28Vin)
82
Iout = 20A (28Vin)
85
Iout = 40A (40Vin)
81
Iout = 20A (40Vin)
83
Load Fault Power Dissipation
Short Circuit Power Dissipation
Product # MQFL-28-2R5S
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Group A
Vin=28V DC ±5%, Iout = 40A, CL = 0 µF, free running10Subgroup13
unless otherwise specified
87
89
87
88
86
87
19
34
20
34
V
V
V
A
Vin = 16V; Iout = 40A
mA
mA
Vin = 16V, 28V, 50V
mA
Vin = 16V, 28V, 50V
mA
Bandwidth = 100 kHz – 10 MHz; see Figure 14
V
Vout at sense leads
V
“
mV
“
; Vin = 16V, 28V, 50V
mV
“
; Vout @ (Iout=0A) - Vout @ (Iout=40A)
V
“
mV
Bandwidth = 10 MHz; CL=11µF
A
W
A
A
Vout ≤ 1.2V
A
mA
µF
mV
Total Iout step = 20A ↔ 40A, 4A ↔ 20A; CL=11µF
mV
“
µs
1,
1,
1,
1,
1,
1,
1,
1,
2,
2,
2,
2,
2,
2,
2,
2,
3
3
3
3
3
3
3
3
1
2, 3
1, 2, 3
1, 2, 3
1, 2, 3
1, 2, 3
1, 2, 3
1, 2, 3
1, 2, 3
1, 2, 3
See Note 5
1, 2, 3
See Note 5
4, 5, 6
4, 5, 6
4, 5, 6
mV
Vin step = 16V ↔ 50V; CL=11µF
mV
“
µs
4, 5, 6
4, 5, 6
See Note 5
ms
Vout = 0.25V → 2.25V
%
ms
ENA1, ENA2 = 5V
ms
ENA2 = 5V
ms
ENA1 = 5V
4, 5, 6
See Note 5
4, 5, 6
4, 5, 6
4, 5, 6
%
%
%
%
%
%
W
Iout at current limit inception point 4
W
Vout ≤ 1.2V
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Doc.# 005-2MQ250S Rev. B
1,
1,
1,
1,
1,
1,
1,
1,
03/19/09
2,
2,
2,
2,
2,
2,
2,
2,
3
3
3
3
3
3
3
3
Page 3
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
MQFL-28-2R5S ELECTRICAL CHARACTERISTICS (Continued)
Parameter
Min. Nom.
Max. Units Notes & Conditions
ISOLATION CHARACTERISTICS
Isolation Voltage (dielectric strength)
Input RTN to Output RTN
500
Any Input Pin to Case
500
Any Output Pin to Case
500
Isolation Resistance (input rtn to output rtn)
100
Isolation Resistance (any pin to case)
100
Isolation Capacitance (input rtn to output rtn)
44
FEATURE CHARACTERISTICS
Switching Frequency (free running)
500
550
600
Synchronization Input
Frequency Range
500
700
Logic Level High
2
10
Logic Level Low
-0.5
0.8
Duty Cycle
20
80
Synchronization Output
Pull Down Current
20
Duty Cycle
25
75
Enable Control (ENA1 and ENA2)
Off-State Voltage
0.8
Module Off Pulldown Current
80
On-State Voltage
2
Module On Pin Leakage Current
20
Pull-Up Voltage
3.2
4.0
4.5
RELIABILITY CHARACTERISTICS
Calculated MTBF (MIL-STD-217F2)
GB @ Tcase=70ºC
AIF @ Tcase=70ºC
Demonstrated MTBF
2800
440
TBD
Device Weight
79
WEIGHT CHARACTERISTICS
Group A
Vin=28V DC ±5%, Iout = 40A, CL = 0 µF, free running10Subgroup13
unless otherwise specified
V
V
V
MW
MW
nF
1
1
1
1
1
1
kHz
1, 2, 3
kHz
V
V
%
1, 2, 3
1, 2, 3
1, 2, 3
See Note 5
mA
%
See Note 5
See Note 5
VSYNC OUT = 0.8V
Output connected to SYNC IN of another MQFL converter
V
1, 2, 3
µA
Current drain required to ensure module is off
See Note 5
V
1, 2, 3
µA
Maximum current draw from pin allowed with module still on See Note 5
V
See Figure A
1, 2, 3
103 Hrs.
103 Hrs.
103 Hrs.
g
Electrical Characteristics Notes
1. Converter will undergo input over-voltage shutdown.
2. Derate output power to 50% of rated power at Tcase = 135º C.
3. High or low state of input voltage must persist for about 200µs to be acted on by the lockout or shutdown circuitry.
4. Current limit inception is defined as the point where the output voltage has dropped to 90% of its nominal value.
5. Parameter not tested but guaranteed to the limit specified.
6. Load current transition time ≥ 10µs.
7. Settling time measured from start of transient to the point where the output voltage has returned to ±50mV of its final value.
8. Line voltage transition time ≥ 100µs.
9. Input voltage rise time ≤ 250µs.
10. Operating the converter at a synchronization frequency above the free running frequency will cause the converter’s efficiency to be
slightly reduced and it may also cause a slight reduction in the maximum output current/power available. For more information consult
the factory.
11. After a disable or fault event, module is inhibited from restarting for 300ms. See Shut Down section on Page 9.
12. SHARE pin outputs a power failure warning pulse during a fault condition. See Current Share section on Page 11.
13. Only the ES and HB grade products are tested at three temperatures. The B and C grade products are tested at one temperature. Please refer to the
ESS table on Page 13 for details.
14. These derating curves apply for the ES- and HB- grade products. The C- grade product has a maximum case temperature of 100º C and a maximum
junction temperature rise of 20º C above TCASE. The B- grade product has a maximum case temperature of 85º C and a maximum junction temperature rise of 20º C at full load.
Product # MQFL-28-2R5S
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Doc.# 005-2MQ250S Rev. B
03/19/09
Page 4
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
100
100
95
95
90
90
Efficiency (%)
Efficiency (%)
Technical Specification
85
80
75
70
80
75
70
16 Vin
28 Vin
65
85
16 Vin
28 Vin
40 Vin
65
40 Vin
60
60
0
5
10
15
20
25
30
35
-55ºC
40
25ºC
Load Current (A)
125ºC
Case Temperature (ºC)
Figure 1: Efficiency at nominal output voltage vs. load current for minimum, nominal, and maximum input voltage at Tcase=25°C.
Figure 2: Efficiency at nominal output voltage and 60% rated power vs.
case temperature for input voltage of 16V, 28V, and 40V.
16
20
18
14
Power Dissipation (W)
Power Dissipation (W)
16
14
12
10
8
6
16 Vin
4
12
10
8
6
4
16 Vin
28 Vin
2
28 Vin
2
40 Vin
40 Vin
0
0
0
5
10
15
20
25
30
35
40
-55ºC
25ºC
Load Current (A)
125ºC
Case Temperature (ºC)
Figure 3: Power dissipation at nominal output voltage vs. load current for
minimum, nominal, and maximum input voltage at Tcase=25°C.
50
Figure 4: Power dissipation at nominal output voltage and 60% rated
power vs. case temperature for input voltage of 16V, 28V, and 40V.
3.0
125
45
40
2.5
100
75
25
20
Output Voltage (V)
30
Pout (W)
Iout (A)
35
50
15
Tjmax = 105ºC
Tjmax = 125ºC
Tjmax = 145ºC
10
5
65
28 Vin
85
105
125 135
0.0
145
0
Figure 5: Output Current / Output Power derating curve as a function of
Tcase and the Maximum desired power MOSFET junction temperature at
Vin = 28V (see Note 14).
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5
10
15
20
25
30
35
40
45
50
Load Current (A)
Case Temperature (ºC)
Product # MQFL-28-2R5S
1.0
0.5
0
45
1.5
25
0
25
2.0
Figure 6: Output voltage vs. load current showing typical current limit curves.
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Doc.# 005-2MQ250S Rev. B
03/19/09
Page 5
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
Figure 7: Turn-on transient at full resistive load and zero output capacitance initiated by ENA1. Input voltage pre-applied. Ch 1: Vout (500mV/
div). Ch 2: ENA1 (5V/div).
Figure 8: Turn-on transient at full resistive load and 10mF output capacitance initiated by ENA1. Input voltage pre-applied. Ch 1: Vout (500mV/
div). Ch 2: ENA1 (5V/div).
Figure 9: Turn-on transient at full resistive load and zero output capacitance initiated by ENA2. Input voltage pre-applied. Ch 1: Vout (500mV/
div). Ch 2: ENA2 (5V/div).
Figure 10: Turn-on transient at full resistive load and zero output capacitance initiated by Vin. ENA1 and ENA2 both previously high. Ch 1: Vout
(500mV/div). Ch 2: Vin (10V/div).
Figure 11: Output voltage response to step-change in load current 50%100%-50% of Iout (max). Load cap: 1µF ceramic cap and 10µF, 100mΩ
ESR tantalum cap. Ch 1: Vout (200mV/div). Ch 2: Iout (20A/div).
Figure 12: Output voltage response to step-change in load current
0%-50%-0% of Iout (max). Load cap: 1µF ceramic cap and 10µF, 100 mΩ
ESR tantalum cap. Ch 1: Vout (200mV/div). Ch 2: Iout (20A/div).
Product # MQFL-28-2R5S
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Doc.# 005-2MQ250S Rev. B
03/19/09
Page 6
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
See Fig. 15
MQME
Filter
iC
See Fig. 16
MQFL
Converter
VSOURCE
VOUT
1 µF
10 µF,
ceramic 100mW ESR
capacitor
capacitor
Figure 13: Output voltage response to step-change in input voltage (16V 50V - 16V). Load cap: 10µF, 100mΩ ESR tantalum cap and 1µF ceramic
cap. Ch 1: Vout (200mV/div). Ch 2: Vin (20V/div).
Figure 14: Test set-up diagram showing measurement points for Input
Terminal Ripple Current (Figure 15) and Output Voltage Ripple (Figure 16).
Figure 15: Input terminal current ripple, ic, at full rated output current
and nominal input voltage with SynQor MQ filter module (50mA/div).
Bandwidth: 20MHz. See Figure 14.
Figure 16: Output voltage ripple, Vout, at nominal input voltage and rated
load current (20mV/div). Load capacitance: 1µF ceramic capacitor and
10µF tantalum capacitor. Bandwidth: 10MHz. See Figure 14.
Figure 17: Rise of output voltage after the removal of a short circuit across
the output terminals. Ch 1: Vout (500mV/div). Ch 2: Iout (20A/div).
Figure 18: SYNC OUT vs. time, driving SYNC IN of a second SynQor
MQFL converter. Ch1: SYNC OUT: (1V/div).
Product # MQFL-28-2R5S
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Doc.# 005-2MQ250S Rev. B
03/19/09
Page 7
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
0.1
0
Forward Transmission (dB)
Output Impedance (ohms)
-10
0.01
0.001
16Vin
28Vin
-20
-30
-40
-50
-60
-70
16Vin
28Vin
-80
40Vin
-90
0.0001
40Vin
-100
10
100
1,000
10,000
100,000
10
100
Hz
1,000
10,000
100,000
Hz
Figure 19: Magnitude of incremental output impedance (Zout = vout/iout)
for minimum, nominal, and maximum input voltage at full rated power.
Figure 20: Magnitude of incremental forward transmission (FT = vout/vin)
for minimum, nominal, and maximum input voltage at full rated power.
10
100
Input Impedance (ohms)
Reverse Transmission (dB)
0
-10
-20
-30
16Vin
28Vin
-40
10
1
16Vin
28Vin
0.1
40Vin
40Vin
-50
0.01
10
100
1,000
10,000
100,000
10
Hz
100
1,000
10,000
100,000
Hz
Figure 21: Magnitude of incremental reverse transmission (RT = iin/iout)
for minimum, nominal, and maximum input voltage at full rated power.
Figure 22: Magnitude of incremental input impedance (Zin = vin/iin) for
minimum, nominal, and maximum input voltage at full rated power.
Figure 23: High frequency conducted emissions of standalone MQFL-2805S, 5Vout module at 120W output, as measured with Method CE102. Limit
line shown is the ‘Basic Curve’ for all applications with a 28V source.
Figure 24: High frequency conducted emissions of MQFL-28-05S, 5Vout
module at 120W output with MQFL-28-P filter, as measured with Method
CE102. Limit line shown is the ‘Basic Curve’ for all applications with a
28V source.
Product # MQFL-28-2R5S
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Doc.# 005-2MQ250S Rev. B
03/19/09
Page 8
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
BASIC OPERATION AND FEATURES
The MQFL DC/DC converter uses a two-stage power conversion
topology. The first, or regulation, stage is a buck-converter that
keeps the output voltage constant over variations in line, load, and
temperature. The second, or isolation, stage uses transformers
to provide the functions of input/output isolation and voltage
transformation to achieve the output voltage required.
Both the regulation and the isolation stages switch at a fixed
frequency for predictable EMI performance. The isolation stage
switches at one half the frequency of the regulation stage, but due
to the push-pull nature of this stage it creates a ripple at double its
switching frequency. As a result, both the input and the output of
the converter have a fundamental ripple frequency of about 550
kHz in the free-running mode.
Rectification of the isolation stage’s output is accomplished with
synchronous rectifiers. These devices, which are MOSFETs with a
very low resistance, dissipate far less energy than would Schottky
diodes. This is the primary reason why the MQFL converters have
such high efficiency, particularly at low output voltages.
CONTROL FEATURES
ENABLE: The MQFL converter has two enable pins. Both must
have a logic high level for the converter to be enabled. A logic
low on either pin will inhibit the converter.
The ENA1 pin (pin 4) is referenced with respect to the converter’s
input return (pin 2). The ENA2 pin (pin 12) is referenced with
respect to the converter’s output return (pin 8). This permits the
converter to be inhibited from either the input or the output side.
Regardless of which pin is used to inhibit the converter, the
regulation and the isolation stages are turned off. However,
when the converter is inhibited through the ENA1 pin, the bias
supply is also turned off, whereas this supply remains on when
the converter is inhibited through the ENA2 pin. A higher input
standby current therefore results in the latter case.
Both enable pins are internally pulled high so that an open
connection on both pins will enable the converter. Figure A
shows the equivalent circuit looking into either enable pins. It is
TTL compatible.
Besides improving efficiency, the synchronous rectifiers permit
operation down to zero load current. There is no longer a need
for a minimum load, as is typical for converters that use diodes
for rectification. The synchronous rectifiers actually permit a
negative load current to flow back into the converter’s output
terminals if the load is a source of short or long term energy. The
MQFL converters employ a “back-drive current limit” to keep this
negative output terminal current small.
There is a control circuit on both the input and output sides of the
MQFL converter that determines the conduction state of the power
switches. These circuits communicate with each other across the
isolation barrier through a magnetically coupled device. No optoisolators are used.
A separate bias supply provides power to both the input and output
control circuits. Among other things, this bias supply permits the
converter to operate indefinitely into a short circuit and to avoid a
hiccup mode, even under a tough start-up condition.
An input under-voltage lockout feature with hysteresis is provided,
as well as an input over-voltage shutdown. There is also
an output current limit that is nearly constant as the load
impedance decreases to a short circuit (i.e., there is not foldback or fold-forward characteristic to the output current under this
condition). When a load fault is removed, the output voltage rises
exponentially to its nominal value without an overshoot.
The MQFL converter’s control circuit does not implement an output
over-voltage limit or an over-temperature shutdown.
The following sections describe the use and operation of additional
control features provided by the MQFL converter.
Product # MQFL-28-2R5S
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Figure A: Equivalent circuit looking into either the ENA1 or ENA2
pins with respect to its corresponding return pin.
SHUT DOWN: The MQFL converter will shut down in response
to only four conditions: ENA1 input low, ENA2 input low, VIN
input below under-voltage lockout threshold, or VIN input above
over-voltage shutdown threshold. Following a shutdown event,
there is a startup inhibit delay which will prevent the converter
from restarting for approximately 300ms. After the 300ms delay
elapses, if the enable inputs are high and the input voltage is
within the operating range, the converter will restart. If the VIN
input is brought down to nearly 0V and back into the operating
range, there is no startup inhibit, and the output voltage will rise
according to the “Turn-On Delay, Rising Vin” specification.
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Doc.# 005-2MQ250S Rev. B
03/19/09
Page 9
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
REMOTE SENSE: The purpose of the remote sense pins is to
correct for the voltage drop along the conductors that connect the
converter’s output to the load. To achieve this goal, a separate
conductor should be used to connect the +SENSE pin (pin 10)
directly to the positive terminal of the load, as shown in the
connection diagram on Page 2. Similarly, the –SENSE pin (pin
9) should be connected through a separate conductor to the return
terminal of the load.
This frequency is either the free-running frequency if there is no
synchronization signal at the SYNC IN pin, or the synchronization
frequency if there is.
NOTE: Even if remote sensing of the load voltage is not
desired, the +SENSE and the -SENSE pins must be connected
to +Vout (pin 7) and OUTPUT RETURN (pin 8), respectively,
to get proper regulation of the converter’s output. If they
are left open, the converter will have an output voltage that
is approximately 200mV higher than its specified value. If
only the +SENSE pin is left open, the output voltage will be
approximately 25mV too high.
NOTE: An MQFL converter that has its SYNC IN pin driven by
the SYNC OUT pin of a second MQFL converter will have its start
of its switching cycle delayed approximately 180 degrees relative
to that of the second converter.
The SYNC OUT signal is available only when the DC input
voltage is above approximately 12V and when the converter is
not inhibited through the ENA1 pin. An inhibit through the ENA2
pin will not turn the SYNC OUT signal off.
Figure B shows the equivalent circuit looking into the SYNC IN
pin. Figure C shows the equivalent circuit looking into the SYNC
OUT pin.
Inside the converter, +SENSE is connected to +Vout with a resistor
value from 100Ω to 274Ω, depending on output voltage, and
–SENSE is connected to OUTPUT RETURN with a 10Ω resistor.
It is also important to note that when remote sense is used, the
voltage across the converter’s output terminals (pins 7 and 8)
will be higher than the converter’s nominal output voltage due to
resistive drops along the connecting wires. This higher voltage at
the terminals produces a greater voltage stress on the converter’s
internal components and may cause the converter to fail to deliver
the desired output voltage at the low end of the input voltage
range at the higher end of the load current and temperature
range. Please consult the factory for details.
Figure B: Equivalent circuit looking into the SYNC IN pin with
respect to the IN RTN (input return) pin.
SYNCHRONIZATION:
The MQFL converter’s switching
frequency can be synchronized to an external frequency source
that is in the 500 kHz to 700 kHz range. A pulse train at the
desired frequency should be applied to the SYNC IN pin (pin 6)
with respect to the INPUT RETURN (pin 2). This pulse train should
have a duty cycle in the 20% to 80% range. Its low value should
be below 0.8V to be guaranteed to be interpreted as a logic low,
and its high value should be above 2.0V to be guaranteed to be
interpreted as a logic high. The transition time between the two
states should be less than 300ns.
If the MQFL converter is not to be synchronized, the SYNC IN pin
should be left open circuit. The converter will then operate in its
free-running mode at a frequency of approximately 550 kHz.
If, due to a fault, the SYNC IN pin is held in either a logic low or
logic high state continuously, the MQFL converter will revert to its
free-running frequency.
The MQFL converter also has a SYNC OUT pin (pin 5). This
output can be used to drive the SYNC IN pins of as many as ten
(10) other MQFL converters. The pulse train coming out of SYNC
OUT has a duty cycle of 50% and a frequency that matches the
switching frequency of the converter with which it is associated.
Product # MQFL-28-2R5S
Phone 1-888-567-9596
Figure C: Equivalent circuit looking into SYNC OUT pin with
respect to the IN RTN (input return) pin.
CURRENT SHARE:
When several MQFL converters are
placed in parallel to achieve either a higher total load power
or N+1 redundancy, their SHARE pins (pin 11) should be
connected together. The voltage on this common SHARE node
represents the average current delivered by all of the paralleled
converters. Each converter monitors this average value and
adjusts itself so that its output current closely matches that of
the average.
www.synqor.com
Doc.# 005-2MQ250S Rev. B
03/19/09
Page 10
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
Since the SHARE pin is monitored with respect to the OUTPUT
RETURN (pin 8) by each converter, it is important to connect all of
the converters’ OUTPUT RETURN pins together through a low DC
and AC impedance. When this is done correctly, the converters
will deliver their appropriate fraction of the total load current to
within +/- 10% at full rated load.
Whether or not converters are paralleled, the voltage at the
SHARE pin could be used to monitor the approximate average
current delivered by the converter(s). A nominal voltage of 1.0V
represents zero current and a nominal voltage of 2.2V represents
the maximum rated current, with a linear relationship in between.
The internal source resistance of a converter’s SHARE pin signal
is 2.5 kW. During an input voltage fault or primary disable event,
the SHARE pin outputs a power failure warning pulse. The SHARE
pin will go to 3V for approximately 14ms as the output voltage
falls.
NOTE: Converters operating from separate input filters with
reverse polarity protection (such as the MQME-28-T filter) with
their outputs connected in parallel may exhibit hiccup operation
at light loads. Consult factory for details.
OUTPUT VOLTAGE TRIM: If desired, it is possible to increase
the MQFL converter’s output voltage above its nominal value. To
do this, use the +SENSE pin (pin 10) for this trim function instead
of for its normal remote sense function, as shown in Figure D.
In this case, a resistor connects the +SENSE pin to the –SENSE
pin (which should still be connected to the output return, either
remotely or locally). The value of the trim resistor should be
chosen according to the following equation or from Figure E:
Rtrim =
407.5
Vout – Vnom – 0.025
where:
Vnom = the converter’s nominal output voltage,
Vout = the desired output voltage (greater than Vnom), and
Rtrim is in Ohms.
1
2
3
4
28Vdc +
–
5
open
means
on
6
Figure E: Output Voltage Trim Graph
As the output voltage is trimmed up, it produces a greater voltage
stress on the converter’s internal components and may cause
the converter to fail to deliver the desired output voltage at the
low end of the input voltage range at the higher end of the load
current and temperature range. Please consult the factory for
details. Factory trimmed converters are available by request.
INPUT UNDER-VOLTAGE LOCKOUT: The MQFL converter
has an under-voltage lockout feature that ensures the converter will
be off if the input voltage is too low. The threshold of input voltage
at which the converter will turn on is higher that the threshold at
which it will turn off. In addition, the MQFL converter will not
respond to a state of the input voltage unless it has remained in
that state for more than about 200µs. This hysteresis and the delay
ensure proper operation when the source impedance is high or in
a noisy environment.
INPUT OVER-VOLTAGE SHUTDOWN: The MQFL converter
also has an over-voltage feature that ensures the converter will be
off if the input voltage is too high. It also has a hysteresis and
time delay to ensure proper operation.
+VIN
ENA 2
IN RTN
SHARE
CASE
+ SNS
ENA 1
– SNS
SYNC OUT
OUT RTN
+VOUT
SYNC IN
12
11
10
9
Rtrim
–
8
7
Load
+
Figure D: Typical connection for output voltage trimming.
Product # MQFL-28-2R5S
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-2MQ250S Rev. B
03/19/09
Page 11
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
BACK-DRIVE CURRENT LIMIT: Converters that use MOSFETs
as synchronous rectifiers are capable of drawing a negative
current from the load if the load is a source of short- or long-term
energy. This negative current is referred to as a “back-drive
current”.
Conditions where back-drive current might occur include paralleled
converters that do not employ current sharing, or where the current
share feature does not adequately ensure sharing during the
startup or shutdown transitions. It can also occur when converters
having different output voltages are connected together through
either explicit or parasitic diodes that, while normally off, become
conductive during startup or shutdown. Finally, some loads, such
as motors, can return energy to their power rail. Even a load
capacitor is a source of back-drive energy for some period of time
during a shutdown transient.
To avoid any problems that might arise due to back-drive current,
the MQFL converters limit the negative current that the converter
can draw from its output terminals. The threshold for this backdrive current limit is placed sufficiently below zero so that the
converter may operate properly down to zero load, but its
absolute value (see the Electrical Characteristics page) is small
compared to the converter’s rated output current.
THERMAL CONSIDERATIONS: Figure 5 shows the suggested
Power Derating Curves for this converter as a function of the case
temperature and the maximum desired power MOSFET junction
temperature. All other components within the converter are cooler
than its hottest MOSFET, which at full power is no more than 20ºC
higher than the case temperature directly below this MOSFET.
Product # MQFL-28-2R5S
Phone 1-888-567-9596
The Mil-HDBK-1547A component derating guideline calls for a
maximum component temperature of 105ºC. Figure 5 therefore
has one power derating curve that ensures this limit is maintained.
It has been SynQor’s extensive experience that reliable long-term
converter operation can be achieved with a maximum component
temperature of 125ºC. In extreme cases, a maximum temperature
of 145ºC is permissible, but not recommended for long-term
operation where high reliability is required. Derating curves for
these higher temperature limits are also included in Figure 5.
The maximum case temperature at which the converter should be
operated is 135ºC.
When the converter is mounted on a metal plate, the plate will
help to make the converter’s case bottom a uniform temperature.
How well it does so depends on the thickness of the plate and
on the thermal conductance of the interface layer (e.g. thermal
grease, thermal pad, etc.) between the case and the plate. Unless
this is done very well, it is important not to mistake the plate’s
temperature for the maximum case temperature. It is easy for
them to be as much as 5-10ºC different at full power and at high
temperatures. It is suggested that a thermocouple be attached
directly to the converter’s case through a small hole in the plate
when investigating how hot the converter is getting. Care must
also be made to ensure that there is not a large thermal resistance
between the thermocouple and the case due to whatever adhesive
might be used to hold the thermocouple in place.
INPUT SYSTEM INSTABILITY: This condition can occur
because any DC/DC converter appears incrementally as a
negative resistance load. A detailed application note titled
“Input System Instability” is available on the SynQor website
which provides an understanding of why this instability arises,
and shows the preferred solution for correcting it.
www.synqor.com
Doc.# 005-2MQ250S Rev. B
03/19/09
Page 12
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
CONSTRUCTION AND ENVIRONMENTAL STRESS SCREENING OPTIONS
Screening
Consistent with
MIL-STD-883F
B-Grade
(-40 ºC to +85 ºC)
C-Grade
(-40 ºC to +100 ºC)
ES-Grade
(-55 ºC to +125 ºC)
(Element Evaluation)
HB-Grade
(-55 ºC to +125 ºC)
(Element Evaluation)
Internal Visual
*
Yes
Yes
Yes
Yes
Temperature Cycle
Method 1010
No
No
Condition B
(-55 ºC to +125 ºC)
Condition C
(-65 ºC to +150 ºC)
Constant
Acceleration
Method 2001
(Y1 Direction)
No
No
500g
Condition A
(5000g)
Burn-in
Method 1015
Load Cycled
• 10s period
• 2s @ 100% Load
• 8s @ 0% Load
12 Hrs @ +100 ºC
24 Hrs @ +125 ºC
96 Hrs @ +125 ºC
160 Hrs @ +125 ºC
Final Electrical Test
Method 5005
(Group A)
+25 ºC
+25 ºC
-45, +25, +100 ºC
-55, +25, +125 ºC
Anodized Package
Full QorSeal
Full QorSeal
Full QorSeal
*
*
Yes
Yes
Ruggedized
QorSeal
QorSeal
QorSeal
Mechanical Seal,
Thermal, and Coating
Process
External Visual
Construction Process
2009
* Per IPC-A-610 (Rev. D) Class 3
MilQor converters and filters are offered in four variations of construction technique and environmental stress screening options. The
three highest grades, C, ES, and HB, all use SynQor’s proprietary QorSeal™ Hi-Rel assembly process that includes a Parylene-C coating
of the circuit, a high performance thermal compound filler, and a nickel barrier gold plated aluminum case. The B-grade version uses
a ruggedized assembly process that includes a medium performance thermal compound filler and a black anodized aluminum case†.
Each successively higher grade has more stringent mechanical and electrical testing, as well as a longer burn-in cycle. The ES- and
HB-Grades are also constructed of components that have been procured through an element evaluation process that pre-qualifies each
new batch of devices.
† Note: Since the surface of the black anodized case is not guaranteed to be electrically conductive, a star washer or similar device
should be used to cut through the surface oxide if electrical connection to the case is desired.
Product # MQFL-28-2R5S
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-2MQ250S Rev. B
03/19/09
Page 13
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
0.093
[2.36]
1
2
3
4
5
6
+VIN
ENA 2
IN RTN
CASE
ENA 1
SHARE
MQFL-28-2R5S-X-HB
DC/DC CONVERTER
28Vin 2.5Vout @ 40A
-SNS
MADE IN USA
SYNC OUT
SYNC IN
+SNS
S/N 0000000 D/C 3205-301 CAGE 1WX10
OUT RTN
+VOUT
12
11
10
9
8
7
0.250 [6.35]
1.50 [38.10]
1.260
[32.00]
0.200 [5.08]
TYP. NON-CUM.
0.040 [1.02]
PIN
2.50 [63.50]
2.76 [70.10]
3.00 [76.20]
0.050 [1.27]
0.128 [3.25]
0.220 [5.59]
2.96 [75.2]
0.228 [5.79]
0.390 [9.91]
Case X
0.093
[2.36]
1
2
3
4
5
6
+VIN
ENA 2
IN RTN
CASE
ENA 1
SHARE
MQFL-28-2R5S-U-HB
SYNC OUT
SYNC IN
+SNS
DC/DC CONVERTER
28Vin 2.5Vout @ 40A
-SNS
MADE IN USA
S/N 0000000 D/C 3205-301 CAGE 1WX10
OUT RTN
+VOUT
2.50 [63.50]
2.76 [70.10]
3.00 [76.20]
12
11
10
9
8
7
0.250 [6.35]
0.200 [5.08]
TYP. NON-CUM.
1.50 [38.10]
1.260
[32.00]
0.040 [1.02]
PIN
0.42
[10.7]
0.128 [3.25]
0.050 [1.27]
0.220 [5.59]
2.80 [71.1]
Case U
0.390 [9.91]
NOTES
PIN DESIGNATIONS
1)
Pins 0.040” (1.02mm) diameter
2)
Pins Material: Copper
Finish: Gold over Nickel plate
1
Positive input
7
Positive output
3)
All dimensions in inches (mm) Tolerances: x.xx +/-0.02 in. (x.x +/-0.5mm)
x.xxx +/-0.010 in. (x.xx +/-0.25mm)
2
Input return
8
Output return
Weight: 2.8 oz (78.5 g) typical
3
CASE
9
- Sense
4)
5)
Workmanship: Meets or exceeds IPC-A-610C Class III
4
Enable 1
10 + Sense
6)
Print Labeling on Top Surface per Product Label Format Drawing
5
Sync output
11 Share
6
Sync input
12 Enable 2
Product # MQFL-28-2R5S
Phone 1-888-567-9596
Pin Function
www.synqor.com
Doc.# 005-2MQ250S Rev. B
Pin Function
03/19/09
Page 14
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
1
2
3
4
5
6
0.300 [7.62]
0.140 [3.56]
1.15 [29.21]
0.250 [6.35]
TYP
+VIN
ENA 2
IN RTN
SHARE
MQFL-28-2R5S-Y-HB
CASE
ENA 1
-SNS
SYNC OUT
SYNC IN
+SNS
DC/DC CONVERTER
28Vin 2.5Vout @ 40A
MADE IN USA
S/N 0000000 D/C 3205-301 CAGE 1WX10
OUT RTN
+VOUT
1.750 [44.45]
0.250 [6.35]
12
2.00
11
[50.80]
10
1.50
9 [38.10]
8
1.750
7
[44.45]
0.200 [5.08]
TYP.
NON-CUM.
0.040
[1.02]
PIN
0.050 [1.27]
0.375 [9.52]
2.50 [63.50]
0.220 [5.59]
2.96 [75.2]
0.228 [5.79]
Case Y
0.390 [9.91]
Case Z
(variant of Y)
0.250 [6.35]
Case W
(variant of Y)
0.250 [6.35]
0.200 [5.08]
TYP. NON-CUM.
0.200 [5.08]
TYP. NON-CUM.
0.040 [1.02]
PIN
0.040 [1.02]
PIN
0.220 [5.59]
0.050 [1.27]
0.420 [10.7]
0.050 [1.27]
0.220 [5.59]
0.36 [9.2]
2.80 [71.1]
0.525 [13.33]
0.390
[9.91]
0.390
[9.91]
0.525 [13.33]
2.80 [71.1]
PIN DESIGNATIONS
NOTES
1)
2)
3)
4)
5)
6)
Pins 0.040” (1.02mm) diameter
Pins Material: Copper
Finish: Gold over Nickel plate
All dimensions in inches (mm) Tolerances: x.xx +/-0.02 in. (x.x +/-0.5mm)
x.xxx +/-0.010 in. (x.xx +/-0.25mm)
Weight: 2.8 oz (78.5 g) typical
Workmanship: Meets or exceeds IPC-A-610C Class III
Print Labeling on Top Surface per Product Label Format Drawing
Product # MQFL-28-2R5S
Phone 1-888-567-9596
www.synqor.com
Pin Function
1
2
3
4
5
6
Positive input
Input return
CASE
Enable 1
Sync output
Sync input
Doc.# 005-2MQ250S Rev. B
Pin Function
7
8
9
10
11
12
Positive output
Output return
- Sense
+ Sense
Share
Enable 2
03/19/09
Page 15
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
MilQor MQFL FAMILY MATRIX
The tables below show the array of MQFL converters available. When ordering SynQor converters, please ensure that you use
the complete part number according to the table in the last page. Contact the factory for other requirements.
Single Output
1.5V
(1R5S)
1.8V
(1R8S)
2.5V
(2R5S)
3.3V
(3R3S)
5V
(05S)
6V
(06S)
7.5V
(7R5S)
9V
(09S)
12V
(12S)
15V
(15S)
28V
(28S)
40A
40A
40A
30A
24A
20A
16A
13A
10A
8A
4A
40A
40A
40A
30A
24A
20A
16A
13A
10A
8A
4A
40A
40A
40A
30A
20A
17A
13A
11A
8A
6.5A
3.3A
40A
40A
40A
30A
20A
17A
13A
11A
8A
6.5A
3.3A
40A
40A
40A
30A
24A
20A
16A
13A
10A
8A
4A
40A
40A
40A
30A
20A
17A
13A
11A
8A
6.5A
3.3A
40A
40A
30A
22A
15A
12A
10A
8A
6A
5A
2.7A
MQFL-28
16-40Vin Cont.
16-50Vin 1s Trans.*
Absolute Max Vin = 60V
MQFL-28E
16-70Vin Cont.
16-80Vin 1s Trans.*
Absolute Max Vin =100V
MQFL-28V
16-40Vin Cont.
5.5-50Vin 1s Trans.*
Absolute Max Vin = 60V
MQFL-28VE
16-70Vin Cont.
5.5-80Vin 1s Trans.*
Absolute Max Vin = 100V
MQFL-270
155-400Vin Cont.
155-475Vin 0.1s Trans.*
Absolute Max Vin = 550V
MQFL-270E
130-475Vin Cont.
130-520Vin 0.1s Trans.*
Absolute Max Vin = 600V
MQFL-270L
65-350Vin Cont.
65-475Vin 0.1s Trans.*
Absolute Max Vin = 550V
Dual Output
5V
(05D)
12V
(12D)
15V
(15D)
24A
Total
10A Total
8A
Total
16-40Vin Cont.
16-50Vin 1s Trans.*
Absolute Max Vin = 60V
24A
Total
10A Total
8A
Total
16-70Vin Cont.
16-80Vin 1s Trans.*
Absolute Max Vin =100V
20A
Total
8A
Total
6.5A
Total
16-40Vin Cont.
5.5-50Vin 1s Trans.*
Absolute Max Vin = 60V
20A
Total
8A
Total
6.5A
Total
16-70Vin Cont.
5.5-80Vin 1s Trans.*
Absolute Max Vin = 100V
MQFL-28
16-40Vin Cont.
16-50Vin 1s Trans.*
Absolute Max Vin = 60V
10A Total 8A Total
155-400Vin Cont.
155-475Vin 0.1s Trans.*
Absolute Max Vin = 550V
22A/
±1A
22A/
±0.8A
15A/
±1A
15A/
±0.8A
2.5A/
±0.8A
22A/
±1A
22A/
±0.8A
15A/
±1A
15A/
±0.8A
2.5A/
±0.8A
22A/
±1A
22A/
±0.8A
15A/
±1A
15A/
±0.8A
2.5A/
±0.8A
22A/
±1A
22A/
±0.8A
15A/
±1A
15A/
±0.8A
2.5A/
±0.8A
22A/
±1A
22A/
±0.8A
15A/
±1A
15A/
±0.8A
2.5A/
±0.8A
22A/
±1A
22A/
±0.8A
15A/
±1A
15A/
±0.8A
2.5A/
±0.8A
22A/
±1A
22A/
±0.8A
15A/
±1A
15A/
±0.8A
2.5A/
±0.8A
MQFL-270E
20A
Total
8A
Total
6.5A
Total
130-475Vin Cont.
130-520Vin 0.1s Trans.*
Absolute Max Vin = 600V
15A
Total
6A
Total
5A
Total
65-350Vin Cont.
65-475Vin 0.1s Trans.*
Absolute Max Vin = 550V
MQFL-270L
65-350Vin Cont.
65-475Vin 0.1s Trans.*
Absolute Max Vin = 550V
30V/±15V
(3015T)
MQFL-270
24A
Total
MQFL-270E
130-475Vin Cont.
130-520Vin 0.1s Trans.*
Absolute Max Vin = 600V
5V/±15V
(0515T)
MQFL-28VE
MQFL-270
155-400Vin Cont.
155-475Vin 0.1s Trans.*
Absolute Max Vin = 550V
5V/±12V
(0512T)
MQFL-28V
MQFL-28VE
16-70Vin Cont.
5.5-80Vin 1s Trans.*
Absolute Max Vin = 100V
3.3V/±15V
(3R315T)
MQFL-28E
MQFL-28V
16-40Vin Cont.
5.5-50Vin 1s Trans.*
Absolute Max Vin = 60V
3.3V/±12V
(3R312T)
MQFL-28
MQFL-28E
16-70Vin Cont.
16-80Vin 1s Trans.*
Absolute Max Vin =100V
Triple Output
MQFL-270L
(75Wmax Total Output Power)
*Converters may be operated continuously at the highest transient input voltage, but some
component electrical and thermal stresses would be beyond MIL-HDBK-1547A guidelines.
Product # MQFL-28-2R5S
Phone 1-888-567-9596
www.synqor.com
†80% of total output current available on
any one output.
Doc.# 005-2MQ250S Rev. B
03/19/09
Page 16
MQFL-28-2R5S
Output: 2.5 V
Current: 40 A
Technical Specification
PART NUMBERING SYSTEM
The part numbering system for SynQor’s MilQor DC-DC converters follows the format shown in the table below.
Model
Name
Input
Voltage
Range
28
28E
28V
28VE
MQFL
270
270E
270L
Output Voltage(s)
Single
Output
Dual
Output
Triple
Output
1R5S
1R8S
2R5S
3R3S
05S
06S
7R5S
09S
12S
15S
28S
05D
12D
15D
3R312T
3R315T
0512T
0515T
3015T
Example:
Package Outline/
Pin Configuration
Screening
Grade
U
X
Y
W
Z
B
C
ES
HB
MQFL – 28VE – 2R5S – Y – ES
APPLICATION NOTES
A variety of application notes and technical white papers can be downloaded in pdf format from the SynQor website.
PATENTS
SynQor holds the following patents, one or more of which might apply to this product:
5,999,417
6,594,159
6,927,987
7,119,524
6,222,742
6,731,520
7,050,309
7,269,034
6,545,890
6,894,468
7,072,190
7,272,021
6,577,109
6,896,526
7,085,146
7,272,023
Contact SynQor for further information:
Phone:
Toll Free:
Fax:
E-mail:
Web:
Address:
Product # MQFL-28-2R5S
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 two (2) 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.# 005-2MQ250S Rev. B
03/19/09
Page 17