MQFL-28-28S-Y-B - SynQor, Inc.

MQFL-28-28S

Single Output

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 1

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RELIABILITY

ELIABILITY DC/DC C

DC/DC CONVERTER

ONVERTER

FULL

ULL P

POWER

OWER O

OPERA

PERATION

TION: -55ºC

: -55ºC TO

TO +125ºC

+125ºC

• 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

Features

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

Specification Compliance

MQFL series converters are:

• Designed for reliability per NAVSO-P3641-A guidelines

• Designed with components derated per:

— MIL-HDBK-1547A

— NAVSO P-3641A

Design Pr

Design Process

ocess

16-40V

16-40V 16-50V

16-50V 28.0V

28.0V 4A

4A 91% @ 2A / 88% @ 4A

91% @ 2A / 88% @ 4A

Continuous Input

Continuous Input T

Transient Input

ransient Input Output

Output Output

Output Efficiency

Efficiency

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

Qualification Pr

Qualification Process

ocess

• AS9100 and ISO 9001:2000 certified facility

• Full component traceability

• Temperature cycling

• Constant acceleration

• 24, 96, 160 hour burn-in

• Three level temperature screening

In-Line Manufacturing Pr

In-Line Manufacturing Process

ocess

DESIGNED & MANUFACTURED IN THE USA

FEATURING QORSEAL™HI-REL ASSEMBLY

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 2

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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TYPICAL CONNECTION DIAGRAM

BLOCK DIAGRAM

−

SENSE

ISOLATION STAGEREGULATION STAGE 7

UVLO

OVSD

SECONDARY

CONTROL

GATE DRIVERS

CONTROL

POWER

PRIMARY

CONTROL

POSITIVE

INPUT

RETURN

CASE

ENABLE 1

SYNC OUTPUT

SYNC INPUT

POSITIVE

OUTPUT

RETURN

ENABLE 2

+ SENSE

GATE DRIVERS

MAGNETIC

DATA COUP LING

ISOLATION BARRIER

CURRENT

LIMIT

CURRENT

SENSE

BIAS POWER

TRANSFORMER

T1 T2 T1 T2

28Vdc

+VIN

Load

IN RTN

CASE

ENA 1

SYNC OUT

MQFL

SYNC IN

ENA 2

+ SNS

– SNS

OUT RTN

+VOUT

open

means

open

means

–

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 3

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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Parameter

Min. Nom. Max. Units Notes & Conditions Group A

Vin=28V DC ±5%, Iout = 4A, CL= 0

F, free running10 Subgroup13

unless otherwise specified

ABSOLUTE MAXIMUM RATINGS

Input Voltage

Non-Operating 60 V

Operating 160 V

Reverse Bias (TCASE = 125ºC) -0.8 V

Reverse Bias (TCASE = -55ºC) -1.2 V

Isolation Voltage (input/output to case, input to output)

Continuous -500 500 V

Transient (≤100

s) -800 800 V

Operating Case Temperature 2-55 135

°C

Storage Case Temperature -65 135

°C

Lead Temperature (20 sec) 300

°C

Voltage at ENA1, ENA2, SYNC IN -1.2 50 V

INPUT CHARACTERISTICS

Operating Input Voltage Range (continuous) 16 28 40 V1, 2, 3

Operating Input Voltage Range (transient, 1 sec) 16 28 50 V 4, 5, 6

Input Under-Voltage Lockout 3

Turn-On Voltage Threshold 14.75 15.50 16.00 V 1, 2, 3

Turn-Off Voltage Threshold 13.80 14.40 15.00 V 1, 2, 3

Lockout Voltage Hysteresis 0.50 1.10 1.80 V 1, 2, 3

Input Over-Voltage Shutdown 3

Turn-Off Voltage Threshold 54.0 56.8 60.0 V 1, 2, 3

Turn-On Voltage Threshold 50.0 51.4 54.0 V 1, 2, 3

Shutdown Voltage Hysteresis 2.0 5.3 8.0 V 1, 2, 3

Maximum Input Current 9.5 A Vin = 16V;

Iout = 4A

1, 2, 3

No Load Input Current (operating) 110 160 mA 1, 2, 3

Disabled Input Current (ENA1) 2 5 mA Vin = 16V, 28V, 50V 1, 2, 3

Disabled Input Current (ENA2) 25 50 mA Vin = 16V, 28V, 50V 1, 2, 3

Input Terminal Current Ripple (peak to peak) 40 60 mA Bandwidth = 100 kHz – 10 MHz; see Figure 14 1, 2, 3

OUTPUT CHARACTERISTICS

Output Voltage Set Point (TCASE = 25ºC) 27.72 28.00 28.28 V Vout at sense leads 1

Output Voltage Set Point Over Temperature 27.60 28.00 28.40 V “ 2, 3

Output Voltage Line Regulation -20 0 20 mV “ ; Vin = 16V, 28V, 50V 1, 2, 3

Output Voltage Load Regulation 120 135 150 mV “ ; Vout @ (Iout=0A) - Vout @ (Iout=4A) 1, 2, 3

Total Output Voltage Range 27.44 28.00 28.56 V “ 1, 2, 3

Output Voltage Ripple and Noise Peak to Peak 30 100 mV Bandwidth = 10 MHz;

CL=11µF

1, 2, 3

Operating Output Current Range 0 4 A 1, 2, 3

Operating Output Power Range 0 112 W 1, 2, 3

Output DC Current-Limit Inception 44.1 4.6 5.0 A 1, 2, 3

Short Circuit Output Current 4.1

4.8 5.5

Vout ≤1.2V 1, 2, 3

Back-Drive Current Limit while Enabled 1.2 A

1, 2, 3

Back-Drive Current Limit while Disabled 10 50 mA

1, 2, 3

Maximum Output Capacitance 3,000

µF See Note 5

DYNAMIC CHARACTERISTICS

Output Voltage Deviation Load Transient

For a Positive Step Change in Load Current -1200 -650 mV Total Iout step = 2A ↔4A, 0.4A ↔2A; CL=11µF 4, 5, 6

For a Negative Step Change in Load Current 650 1200 mV “ 4, 5, 6

Settling Time (either case)

50 200 µs 4, 5, 6

Output Voltage Deviation Line Transient

For a Positive Step Change in Line Voltage -800 800 mV Vin step = 16V ↔50V; CL=11µF; Iout=3.5A 4, 5, 6

For a Negative Step Change in Line Voltage -800 800 mV “ 4, 5, 6

Settling Time (either case)

250 500 µs See Note 5

Turn-On Transient

Output Voltage Rise Time 6 10 ms Vout = 2.8V →25.2V 4, 5, 6

Output Voltage Overshoot 0 2 % See Note 5

Turn-On Delay, Rising Vin

5.5 8.0 ms ENA1, ENA2 = 5V 4, 5, 6

Turn-On Delay, Rising ENA1 3.0 6.0 ms ENA2 = 5V 4, 5, 6

Turn-On Delay, Rising ENA2 1.5 3.0 ms ENA1 = 5V 4, 5, 6

EFFICIENCY

Iout = 4A (16Vin) 84 88 %

1, 2, 3

Iout = 2A (16Vin) 88 91 %

1, 2, 3

Iout = 4A (28Vin) 84 88 %

1, 2, 3

Iout = 2A (28Vin) 87 91 %

1, 2, 3

Iout = 4A (40Vin) 83 87 %

1, 2, 3

Iout = 2A (40Vin) 85 89 %

1, 2, 3

Load Fault Power Dissipation 22 32 W Iout at current limit inception point

41, 2, 3

Short Circuit Power Dissipation 24 33 W Vout ≤1.2V 1, 2, 3

MQFL-28-28S ELECTRICAL CHARACTERISTICS

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 4

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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MQFL-28-28S ELECTRICAL CHARACTERISTICS (Continued)

Parameter

Min. Nom. Max. Units Notes & Conditions Group A

Vin=28V DC ±5%, Iout = 4A, CL= 0

F, free running10 Subgroup13

unless otherwise specified

ISOLATION CHARACTERISTICS

Isolation Voltage (dielectric strength)

Input RTN to Output RTN 500 V 1

Any Input Pin to Case 500 V 1

Any Output Pin to Case 500 V 1

Isolation Resistance (input rtn to output rtn) 100 M

Ω

Isolation Resistance (any pin to case) 100 M

Ω

Isolation Capacitance (input rtn to output rtn) 44 nF 1

FEATURE CHARACTERISTICS

Switching Frequency (free running) 500 550 600 kHz 1, 2, 3

Synchronization Input

Frequency Range 500 700 kHz 1, 2, 3

Logic Level High 2 10 V 1, 2, 3

Logic Level Low -0.5 0.8 V 1, 2, 3

Duty Cycle 20 80 %See Note 5

Synchronization Output

Pull Down Current 20 mA VSYNC OUT = 0.8V See Note 5

Duty Cycle 25 75 % Output connected to SYNC IN of another MQFL converter See Note 5

Enable Control (ENA1 and ENA2)

Off-State Voltage 0.8 V 1, 2, 3

Module Off Pulldown Current 80 µA Current drain required to ensure module is off See Note 5

On-State Voltage 2 V 1, 2, 3

Module On Pin Leakage Current 20 µA Maximum current draw from pin allowed with module still on See Note 5

Pull-Up Voltage 3.2 4.0 4.5 V See Figure A 1, 2, 3

RELIABILITY CHARACTERISTICS

Calculated MTBF (MIL-STD-217F2)

GB @ Tcase=70

C 2800 103Hrs.

AIF @ Tcase=70

C 440 103Hrs.

Demonstrated MTBF TBD 103Hrs.

WEIGHT CHARACTERISTICS

Device Weight 79 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 200

s 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 ≥10

7. Settling time measured from start of transient to the point where the output voltage has returned to ±1% of its final value.

8. Line voltage transition time ≥100

9. Input voltage rise time ≤250

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 tempera-

ture rise of 20º C at full load.

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 5

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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100

01234

Load Curr ent (A)

Efficiency (%)

16 V in

28 V in

40 V in

Figure 1: Efficiency at nominal output voltage vs. load current for min-

imum, nominal, and maximum input voltage at T

CASE=25

100

-55ºC 25ºC 125ºC

Case Temperature ( ºC)

Efficiency (%)

16 V in

28 Vin

40 V in

Figure 2: Efficiency at nominal output voltage and 60% rated power vs.

case temperature for input voltage of 16V, 28V, and 40V.

0 1 2 3 4

Load Curr ent (A)

Power Dissipation (W)

16 V in

28 V in

40 V in

Figure 3: Power dissipation at nominal output voltage vs. load current

for minimum, nominal, and maximum input voltage at T

CASE=25

-55ºC 25ºC 125ºC

Case Temperature ( ºC)

Power Dissipation (W)

16 V in

28 V in

40 V in

Figure 4: Power dissipation at nominal output voltage and 60% rated

power vs. case temperature for input voltage of 16V, 28V, and 40V.

25 45 65 85 105 125 145

Case Temperat ur e ( ºC)

Iout (A)

112

140

168

= 105ºC

= 125ºC

= 145ºC

Pout (W)

Figure 5: Output Current / Output Power derating curve as a function

of T

CASE and the Maximum desired power MOSFET junction tempera-

ture at Vin = 28V (see Note 14).

0123456

Load Curr ent ( A)

Output Voltage (V)

28 Vi n

Figure 6: Output voltage vs. load current showing typical current limit

curves.

Tjmax

135

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 6

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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Figure 7: Turn-on transient at full resistive load and zero output capac-

itance initiated by ENA1. Input voltage pre-applied. Ch 1: Vout

(5V/div). Ch 2: ENA1 (5V/div).

Figure 8: Turn-on transient at full resistive load and 3 mF output

capacitance initiated by ENA1. Input voltage pre-applied. Ch 1: Vout

(5V/div). Ch 2: ENA1 (5V/div).

Figure 9: Turn-on transient at full resistive load and zero output capac-

itance initiated by ENA2. Input voltage pre-applied. Ch 1: Vout

(5V/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 (5V/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: 1

F ceramic cap and 10

F, 100 m

Ω

ESR

tantalum cap. Ch 1: Vout (500mV/div). Ch 2: Iout (2A/div).

Figure 12: Output voltage response to step-change in load current (0%-50%-

0% of Iout (max). Load cap: 1

F ceramic cap and 10

F, 100 m

Ω

ESR tanta-

lum cap. Ch 1: Vout (500mV/div). Ch 2: Iout (2A/div).

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 7

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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Figure 13: Output voltage response to step-change in input voltage (16V -

50V - 16V). Load cap: 10

F, 100 m

Ω

ESR tantalum cap and 1

F ceramic

cap. Ch 1: Vout (500mV/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).

MQFL

Converter

MQME

Filter

See Fig. 15 See Fig. 16

ceramic

capacitor

100m

Ω

ESR

capacitor

VSOURCE

iCVOUT

Figure 15: Input terminal current ripple, ic, at full rated output current

and nominal input voltage with SynQor MQ filter module (50 mA/div).

Bandwidth: 20MHz. See Figure 14.

Figure 16: Output voltage ripple, Vout, at nominal input voltage and

rated load current (20 mV/div). Load capacitance: 1

F ceramic capac-

itor and 10

F tantalum capacitor. Bandwidth: 10 MHz. See Figure 14.

Figure 17: Rise of output voltage after the removal of a short circuit

across the output terminals. Ch 1: Vout (5V/div). Ch 2: Iout (2A/div). Figure 18: SYNC OUT vs. time, driving SYNC IN of a second SynQor

MQFL converter. Ch1: SYNC OUT: (1V/div).

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 8

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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0.01

0.1

10 100 1,000 10,000 100,000

Output Impedance (ohms)

16Vin

28Vin

40Vin

Figure 23: High frequency conducted emissions of standalone MQFL-28-

05S, 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 fr equency conducted emissions of MQFL-28-05S, 5Vout mod-

ule 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.

Figure 19: Magnitude of incremental output impedance (Zout =

vout/iout) for minimum, nominal, and maximum input voltage at full

rated power.

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

10 100 1,000 10,000 100,000

Forward Transmission (dB)

16Vin

28Vin

40Vin

Figure 20: Magnitude of incremental forward transmission (FT =

vout/vin) for minimum, nominal, and maximum input voltage at full

rated power.

-50

-40

-30

-20

-10

10 100 1,000 10,000 100,000

Reverse Transmission (dB)

16Vin

28Vin

40Vin

Figure 21: Magnitude of incremental reverse transmission (RT =

iin/iout) for minimum, nominal, and maximum input voltage at full rated

power.

0.01

0.1

100

10 100 1,000 10,000 100,000

Input Impedance (ohms)

16Vin

28Vin

40Vin

Figure 22: Magnitude of incremental input impedance (Zin = vin/iin)

for minimum, nominal, and maximum input

voltage at full rated power.

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 9

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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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 transform-

ers 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 fre-

quency 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 dou-

ble 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 con-

verters have such high efficiency, particularly at low output volt-

ages.

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 neg-

ative load current to flow back into the converter’s output termi-

nals 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 opto-isolators are used.

A separate bias supply provides power to both the input and out-

put 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 out-

put current limit that is nearly constant as the load impedance

decreases to a short circuit (i.e., there is not fold-back or fold-for-

ward characteristic to the output current under this condition).

When a load fault is removed, the output voltage rises exponen-

tially to its nominal value without an overshoot.

The MQFL converter’s control circuit does not implement an out-

put over-voltage limit or an over-temperature shutdown.

The following sections describe the use and operation of addi-

tional control features provided by the MQFL converter.

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 reg-

ulation 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 con-

verter 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 con-

nection on both pins will enable the converter. Figure A shows

the equivalent circuit looking into either enable pins. It is TTL

compatible.

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

2N3904

1N4148

250K

125K

82K

5.6V

TO ENABLE

CIRCUITRY

PIN 4

(or PIN 12)

PIN 2

(or PIN 8) RTN

ENABLE

Figure A: Equivalent circuit looking into either the ENA1 or ENA2

pins with respect to its corresponding return pin.

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 10

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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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.

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 con-

nection diagram on Page 2. Similarly, the –SENSE pin (pin 9)

should be connected through a separate conductor to the return

terminal of the load.

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 con-

verter 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.

Inside the converter, +SENSE is connected to +Vout with a 100Ω

resistor and –SENSE is connected to OUTPUT RETURN with a

10Ωresistor.

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 convert-

er’s internal components and may cause the converter to fail to

deliver the desired output voltage at the low end of the input volt-

age range at the higher end of the load current and temperature

range. Please consult the factory for details.

SYNCHRONIZATION: The MQFL converter’s switching fre-

quency 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 out-

put 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.

This frequency is either the free-running frequency if there is no

synchronization signal at the SYNC IN pin, or the synchroniza-

tion frequency if there is.

The SYNC OUT signal is available only when the DC input volt-

age 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.

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 rela-

tive to that of the second converter.

Figure B shows the equivalent circuit looking into the SYNC IN

pin. Figure C shows the equivalent circuit looking into the SYNC

OUT pin.

PIN 2

PIN 6

SYNC IN

IN RTN

TO SYNC

CIRCUITRY

Figure B: Equivalent circuit looking into the SYNC IN pin with

respect to the IN RTN (input return) pin.

FROM SYNC

CIRCUITRY

SYNC OUT

IN RTN PIN 2

PIN 5

OPEN COLLECTOR

OUTPUT

Figure C: Equivalent circuit looking into SYNC OUT pin with

respect to the IN RTN (input return) pin.

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 11

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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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.

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 con-

verters will deliver their appropriate fraction of the total load cur-

rent 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 kΩ. 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 cho-

sen according to the following equation or from Figure E:

Rtrim = 100 x Vnom

[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.

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 cur-

rent and temperature range. Please consult the factory for

details. Factory trimmed converters are available by request.

Figure D: Typical connection for output voltage trimming.

28Vdc

+VIN

Load

IN RTN

CASE

ENA 1

SYNC OUT

SYNC IN

ENA 2

+ SNS

– SNS

OUT RTN

+VOUT

open

means

Rtrim

–

100

1,000

10,000

100,000

00.5 11.5 22.5 3

I ncr ea se in Vout ( V)

Trim Resistance (ohms)

Figure E: Output Voltage Trim Graph

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 12

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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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 200

s. This hysteresis

and the delay ensure proper operation when the source imped-

ance 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.

BACK-DRIVE CURRENT LIMIT: Converters that use MOSFETs

as synchronous rectifiers are capable of drawing a negative cur-

rent 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 cur-

rent”.

Conditions where back-drive current might occur include paral-

leled 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 con-

verters 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 back-

drive 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 cool-

er than its hottest MOSFET, which at full power is no more than

20ºC higher than the case temperature directly below this MOS-

FET.

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 main-

tained. 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 convert-

er 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 ther-

mal 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.

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 13

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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CONSTRUCTION AND ENVIRONMENTAL STRESS SCREENING OPTIONS

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 coat-

ing 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.

QorSealQorSealQorSealRuggedized

Construction

Process

YesYes

2009

External Visual

Full QorSealFull QorSealFull QorSealAnodized Package

Mechanical Seal,

Thermal, and

Coating Process

+25oC

24 Hrs @ +125oC

Yes

C-Grade

(-40oC to +100 oC)

* Per IPC-A-610 (Rev. D) Class 3

160 Hrs @ +125oC96 Hrs @ +125oC12 Hrs @ +100oC

Method 1015

Load Cycled

•10s period

•2s @ 100% Load

•8s @ 0% Load

Burn-in

Condition A

(5000g)

500gNo

Method 2001

(Y1 Direction)

Constant

Acceleration

Condition C

(-65oC to +150 oC)

Condition B

(-55oC to +125 oC)

NoMethod 1010

Temperature Cycle

YesYesYes

Internal Visual

-55, +25, +125oC-45, +25, +100oC+25oC

Method 5005

(Group A)

Final Electrical Test

HB-Grade

(-55oC to +125 oC)

(Element Evaluation)

ES-Grade

(-55oC to +125 oC)

(Element Evaluation)

B-Grade

(-40oC to +85oC)

Consistent with

MIL-STD-883F

Screening

QorSealQorSealQorSealRuggedized

Construction

Process

YesYes

2009

External Visual

Full QorSealFull QorSealFull QorSealAnodized Package

Mechanical Seal,

Thermal, and

Coating Process

+25oC

24 Hrs @ +125oC

Yes

C-Grade

(-40oC to +100 oC)

* Per IPC-A-610 (Rev. D) Class 3

160 Hrs @ +125oC96 Hrs @ +125oC12 Hrs @ +100oC

Method 1015

Load Cycled

•10s period

•2s @ 100% Load

•8s @ 0% Load

Burn-in

Condition A

(5000g)

500gNo

Method 2001

(Y1 Direction)

Constant

Acceleration

Condition C

(-65oC to +150 oC)

Condition B

(-55oC to +125 oC)

NoMethod 1010

Temperature Cycle

YesYesYes

Internal Visual

-55, +25, +125oC-45, +25, +100oC+25oC

Method 5005

(Group A)

Final Electrical Test

HB-Grade

(-55oC to +125 oC)

(Element Evaluation)

ES-Grade

(-55oC to +125 oC)

(Element Evaluation)

B-Grade

(-40oC to +85oC)

Consistent with

MIL-STD-883F

Screening

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 14

Output:

Current:

28.0 V

4 A

MQFL-28-28S

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Pin # Function

1 POSITIVE INPUT

2 INPUT RETURN

3CASE

4 ENABLE 1

5 SYNC OUTPUT

6SYNC INPUT

7POSITIVE OUTPUT

8 OUTPUT RETURN

9- SENSE

10 + SENSE

11 SHARE

12 ENABLE 2

PACKAGE PINOUTS

MQFL-28-28S-X-HB

DC/DC CONVERTER

28Vin 28.0Vout @ 4A

MQFL-28-28S-Y-HB

DC/DC CONVERTER

28Vin 28.0Vout @ 4A

NOTES

1) Case: Aluminum with gold over nick-

el plate finish for the C-, ES-, and HB-

Grade products.

Aluminum with black anodized finish

for the B-Grade products.

2) Pins: Diameter: 0.040” (1.02mm)

Material: Copper

Finish: Gold over Nickel plate

3) All dimensions as inches (mm)

4) Tolerances: a) x.xx +0.02”

(x.x +0.5mm)

b) x.xxx +0.010”

(x.xx +0.25mm)

5) Weight: 2.8 oz. (79 g) typical

6) Workmanship: Meets or exceeds IPC-

A-610C Class III

Product # MQFL-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 15

Output:

Current:

28.0 V

4 A

MQFL-28-28S

TTee

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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 Converters

Triple Output ConvertersDual Output Converters†

40A

1.5V

(1R5S)

3.3A6.58A11A13A17A20A30A40A40A

MQFL

MQFL-

-270E

270E

130

130-

-475Vin Cont.

475Vin Cont.

130

130-

-520Vin 0.1s Trans.

520Vin 0.1s Trans.*

Absolute Max Vin = 600V

10A

16A

13A

16A

7.5V

(7R5S) 28V

(28S)

15V

(15S)

12V

(12S)

(09S)

(06S)

(05S)

3.3V

(3R3S)

2.5V

(2R5S)

1.8V

(1R8S)

2.7A

3.3A

5A6A8A12A15A22A30A40A

MQFL

MQFL-

-270L

270L

65-

-350Vin Cont.

350Vin Cont.

65-

-475Vin 0.1s Trans.

475Vin 0.1s Trans.*

Absolute Max Vin = 550V

8A10A13A20A24A30A40A40A

MQFL

MQFL-

-270

270

155

155-

-400Vin Cont.

400Vin Cont.

155

155-

-475Vin 0.1s Trans.

475Vin 0.1s Trans.*

Absolute Max Vin = 550V

6.58A11A17A20A30A40A40A

MQFL

MQFL-

-28VE

28VE

16-

-70Vin Cont.

70Vin Cont.

5.5

5.5-

-80Vin 1s Trans.

80Vin 1s Trans.*

Absolute Max Vin = 100V

6.58A11A17A20A30A40A40A

MQFL

MQFL-

-28V

28V

16-

-40Vin Cont.

40Vin Cont.

5.5

5.5-

-50Vin 1s Trans.

50Vin 1s Trans.*

Absolute Max Vin = 60V

8A10A13A20A24A30A40A40A

MQFL

MQFL-

-28E

28E

16-

-70Vin Cont.

70Vin Cont.

16-

-80Vin 1s Trans.

80Vin 1s Trans.*

Absolute Max Vin =100V

8A10A13A20A24A30A40A40A

MQFL

MQFL-

-28

16-

-40Vin Cont.

40Vin Cont.

16-

-50Vin 1s Trans.

50Vin 1s Trans.*

Absolute Max Vin = 60V

40A

1.5V

(1R5S)

3.3A6.58A11A13A17A20A30A40A40A

MQFL

MQFL-

-270E

270E

130

130-

-475Vin Cont.

475Vin Cont.

130

130-

-520Vin 0.1s Trans.

520Vin 0.1s Trans.*

Absolute Max Vin = 600V

10A

16A

13A

16A

7.5V

(7R5S) 28V

(28S)

15V

(15S)

12V

(12S)

(09S)

(06S)

(05S)

3.3V

(3R3S)

2.5V

(2R5S)

1.8V

(1R8S)

2.7A

3.3A

5A6A8A12A15A22A30A40A

MQFL

MQFL-

-270L

270L

65-

-350Vin Cont.

350Vin Cont.

65-

-475Vin 0.1s Trans.

475Vin 0.1s Trans.*

Absolute Max Vin = 550V

8A10A13A20A24A30A40A40A

MQFL

MQFL-

-270

270

155

155-

-400Vin Cont.

400Vin Cont.

155

155-

-475Vin 0.1s Trans.

475Vin 0.1s Trans.*

Absolute Max Vin = 550V

6.58A11A17A20A30A40A40A

MQFL

MQFL-

-28VE

28VE

16-

-70Vin Cont.

70Vin Cont.

5.5

5.5-

-80Vin 1s Trans.

80Vin 1s Trans.*

Absolute Max Vin = 100V

6.58A11A17A20A30A40A40A

MQFL

MQFL-

-28V

28V

16-

-40Vin Cont.

40Vin Cont.

5.5

5.5-

-50Vin 1s Trans.

50Vin 1s Trans.*

Absolute Max Vin = 60V

8A10A13A20A24A30A40A40A

MQFL

MQFL-

-28E

28E

16-

-70Vin Cont.

70Vin Cont.

16-

-80Vin 1s Trans.

80Vin 1s Trans.*

Absolute Max Vin =100V

8A10A13A20A24A30A40A40A

MQFL

MQFL-

-28

16-

-40Vin Cont.

40Vin Cont.

16-

-50Vin 1s Trans.

50Vin 1s Trans.*

Absolute Max Vin = 60V

15A

Total

20A

Total

20A

Total

20A

Total

20A

Total

20A

Total

20A

Total

±5V

(05D)

6.5A

Total

MQFL

MQFL-

-270E

270E

130

130-

-475Vin Cont.

475Vin Cont.

130

130-

-520Vin 0.1s Trans.

520Vin 0.1s Trans.*

Absolute Max Vin = 600V

±15V

(15D)

±12V

(12D)

Total

10A

Total

10A

Total

10A

Total

6.5A

Total

6.5A

Total

MQFL

MQFL-

-270L

270L

65-

-350Vin Cont.

350Vin Cont.

65-

-475Vin 0.1s Trans.

475Vin 0.1s Trans.*

Absolute Max Vin = 550V

MQFL

MQFL-

-270

270

155

155-

-400Vin Cont.

400Vin Cont.

155

155-

-475Vin 0.1s Trans.

475Vin 0.1s Trans.*

Absolute Max Vin = 550V

MQFL

MQFL-

-28VE

28VE

16-

-70Vin Cont.

70Vin Cont.

5.5

5.5-

-80Vin 1s Trans.

80Vin 1s Trans.*

Absolute Max Vin = 100V

MQFL

MQFL-

-28V

28V

16-

-40Vin Cont.

40Vin Cont.

5.5

5.5-

-50Vin 1s Trans.

50Vin 1s Trans.*

Absolute Max Vin = 60V

MQFL

MQFL-

-28E

28E

16-

-70Vin Cont.

70Vin Cont.

16-

-80Vin 1s Trans.

80Vin 1s Trans.*

Absolute Max Vin =100V

MQFL

MQFL-

-28

16-

-40Vin Cont.

40Vin Cont.

16-

-50Vin 1s Trans.

50Vin 1s Trans.*

Absolute Max Vin = 60V

15A

Total

20A

Total

20A

Total

20A

Total

20A

Total

20A

Total

20A

Total

±5V

(05D)

6.5A

Total

MQFL

MQFL-

-270E

270E

130

130-

-475Vin Cont.

475Vin Cont.

130

130-

-520Vin 0.1s Trans.

520Vin 0.1s Trans.*

Absolute Max Vin = 600V

±15V

(15D)

±12V

(12D)

Total

10A

Total

10A

Total

10A

Total

6.5A

Total

6.5A

Total

MQFL

MQFL-

-270L

270L

65-

-350Vin Cont.

350Vin Cont.

65-

-475Vin 0.1s Trans.

475Vin 0.1s Trans.*

Absolute Max Vin = 550V

MQFL

MQFL-

-270

270

155

155-

-400Vin Cont.

400Vin Cont.

155

155-

-475Vin 0.1s Trans.

475Vin 0.1s Trans.*

Absolute Max Vin = 550V

MQFL

MQFL-

-28VE

28VE

16-

-70Vin Cont.

70Vin Cont.

5.5

5.5-

-80Vin 1s Trans.

80Vin 1s Trans.*

Absolute Max Vin = 100V

MQFL

MQFL-

-28V

28V

16-

-40Vin Cont.

40Vin Cont.

5.5

5.5-

-50Vin 1s Trans.

50Vin 1s Trans.*

Absolute Max Vin = 60V

MQFL

MQFL-

-28E

28E

16-

-70Vin Cont.

70Vin Cont.

16-

-80Vin 1s Trans.

80Vin 1s Trans.*

Absolute Max Vin =100V

MQFL

MQFL-

-28

16-

-40Vin Cont.

40Vin Cont.

16-

-50Vin 1s Trans.

50Vin 1s Trans.*

Absolute Max Vin = 60V

15A/

±0.8A

15A/

±0.8A

15A/

±0.8A

15A/

±0.8A

15A/

±0.8A

15A/

±0.8A

15A/

±0.8A

5V/±15V

(0515T)

2.5A/

±0.8A

15A/

±1A

22A/

±0.8A

22A/

±1A

MQFL

MQFL-

-270E

270E

130

130-

-475Vin Cont.

475Vin Cont.

130

130-

-520Vin 0.1s Trans.

520Vin 0.1s Trans.*

Absolute Max Vin = 600V

15A/

±1A

15A/

±1A

15A/

±1A

15A/

±1A

15A/

±1A

15A/

±1A

5V/±12V

(0512T) 30V/±15V

(3015T)

3.3V/±15V

(3R315T)

3.3V/±12V

(3R312T)

22A/

±1A

22A/

±1A

22A/

±1A

22A/

±1A

22A/

±1A

22A/

±1A

22A/

±0.8A

22A/

±0.8A

22A/

±0.8A

22A/

±0.8A

22A/

±0.8A

22A/

±0.8A

2.5A/

±0.8A

MQFL

MQFL-

-270L

270L

65-

-350Vin Cont.

350Vin Cont.

65-

-475Vin 0.1s Trans.

475Vin 0.1s Trans.*

Absolute Max Vin = 550V

2.5A/

±0.8A

MQFL

MQFL-

-270

270

155

155-

-400Vin Cont.

400Vin Cont.

155

155-

-475Vin 0.1s Trans.

475Vin 0.1s Trans.*

Absolute Max Vin = 550V

2.5A/

±0.8A

MQFL

MQFL-

-28VE

28VE

16-

-70Vin Cont.

70Vin Cont.

5.5

5.5-

-80Vin 1s Trans.

80Vin 1s Trans.*

Absolute Max Vin = 100V

2.5A/

±0.8A

MQFL

MQFL-

-28V

28V

16-

-40Vin Cont.

40Vin Cont.

5.5

5.5-

-50Vin 1s Trans.

50Vin 1s Trans.*

Absolute Max Vin = 60V

2.5A/

±0.8A

MQFL

MQFL-

-28E

28E

16-

-70Vin Cont.

70Vin Cont.

16-

-80Vin 1s Trans.

80Vin 1s Trans.*

Absolute Max Vin =100V

2.5A/

±0.8A

MQFL

MQFL-

-28

16-

-40Vin Cont.

40Vin Cont.

16-

-50Vin 1s Trans.

50Vin 1s Trans.*

Absolute Max Vin = 60V

15A/

±0.8A

15A/

±0.8A

15A/

±0.8A

15A/

±0.8A

15A/

±0.8A

15A/

±0.8A

15A/

±0.8A

5V/±15V

(0515T)

2.5A/

±0.8A

15A/

±1A

22A/

±0.8A

22A/

±1A

MQFL

MQFL-

-270E

270E

130

130-

-475Vin Cont.

475Vin Cont.

130

130-

-520Vin 0.1s Trans.

520Vin 0.1s Trans.*

Absolute Max Vin = 600V

15A/

±1A

15A/

±1A

15A/

±1A

15A/

±1A

15A/

±1A

15A/

±1A

5V/±12V

(0512T) 30V/±15V

(3015T)

3.3V/±15V

(3R315T)

3.3V/±12V

(3R312T)

22A/

±1A

22A/

±1A

22A/

±1A

22A/

±1A

22A/

±1A

22A/

±1A

22A/

±0.8A

22A/

±0.8A

22A/

±0.8A

22A/

±0.8A

22A/

±0.8A

22A/

±0.8A

2.5A/

±0.8A

MQFL

MQFL-

-270L

270L

65-

-350Vin Cont.

350Vin Cont.

65-

-475Vin 0.1s Trans.

475Vin 0.1s Trans.*

Absolute Max Vin = 550V

2.5A/

±0.8A

MQFL

MQFL-

-270

270

155

155-

-400Vin Cont.

400Vin Cont.

155

155-

-475Vin 0.1s Trans.

475Vin 0.1s Trans.*

Absolute Max Vin = 550V

2.5A/

±0.8A

MQFL

MQFL-

-28VE

28VE

16-

-70Vin Cont.

70Vin Cont.

5.5

5.5-

-80Vin 1s Trans.

80Vin 1s Trans.*

Absolute Max Vin = 100V

2.5A/

±0.8A

MQFL

MQFL-

-28V

28V

16-

-40Vin Cont.

40Vin Cont.

5.5

5.5-

-50Vin 1s Trans.

50Vin 1s Trans.*

Absolute Max Vin = 60V

2.5A/

±0.8A

MQFL

MQFL-

-28E

28E

16-

-70Vin Cont.

70Vin Cont.

16-

-80Vin 1s Trans.

80Vin 1s Trans.*

Absolute Max Vin =100V

2.5A/

±0.8A

MQFL

MQFL-

-28

16-

-40Vin Cont.

40Vin Cont.

16-

-50Vin 1s Trans.

50Vin 1s Trans.*

Absolute Max Vin = 60V

(75Wmax Total O u tp u t Power)

†80% of total output current available on

any one output.

*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-28-28S Phone 1-888-567-9596 www.synqor.com Doc.# 005-2MQ280S Rev. B 2/27/08 Page 16

Output:

Current:

28.0 V

4 A

MQFL-28-28S

TTee

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cchh

hhnn

nnii

iicc

ccaa

aall

SSpp

ppee

eecc

ccii

iiff

ffii

iicc

ccaa

aatt

ttii

iioo

oonn

PART NUMBERING SYSTEM

The part numbering system for SynQor’s MilQor DC/DC converters follows the format shown in the table below.

Example: MQFL – 28VE – 28S – Y – ES

APPLICATION NOTES

A variety of application notes and technical white papers can be downloaded in pdf format from the SynQor website.

Triple

Output

Dual

Output

Single

Output

Output Voltage(s)

1R5S

1R8S

2R5S

3R3S

05S

06S

7R5S

09S

12S

15S

28S

05D

12D

15D

Package Outline/

Pin Configuration

Screening

Grade

3R312T

3R315T

0512T

0515T

3015T

28E

28V

28VE

270

270E

270L

MQFL

Input

Voltage

Range

Model

Name Triple

Output

Dual

Output

Single

Output

Output Voltage(s)

1R5S

1R8S

2R5S

3R3S

05S

06S

7R5S

09S

12S

15S

28S

05D

12D

15D

Package Outline/

Pin Configuration

Screening

Grade

3R312T

3R315T

0512T

0515T

3015T

28E

28V

28VE

270

270E

270L

MQFL

Input

Voltage

Range

Model

Name

PATENTS (additional patent applications may be filed)

SynQor holds the following patents, one or more of which might apply to this product:

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

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.

Contact SynQor for further information:

Phone: 978-849-0600

Toll Free: 888-567-9596

Fax: 978-849-0602

E-mail: power@synqor.com

Web: www.synqor.com

Address: 155 Swanson Road

Boxborough, MA 01719

USA