MQFL-28V-2R5S Single Output H igH R eliability DC-DC C onveRteR 16-40V 5.5-50V 2.5V 40A 88% @ 20A / 87% @ 40A Continuous Input Transient Input Output Output Efficiency F ull P oweR o PeRation : -55ºC to +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 QorSeal® packaging approach ensures survivability in the most hostile environments. Compatible 2 ENA with the industry standard format, these converters operate RE SHA at a fixed frequency, have no opto-isolators, and follow conservative component derating guidelines. -ES S-Y 5 -2R -28V tER +VIN They are N IN RT ILITY STAB designed and manufactured to comply with a wide range of 1 ENA VER FL MQ DC Con ut@40A E AG DC.5Vo 1C in 2 5-30 320 28V D/C T C OU SYN C IN SYN military standards. +SNS -SNS RTN OUT T +VOU X10 1W 0 000 000 S/n Meets all -704 and -1275D under-voltage transients Design Process 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 In-Line Manufacturing Process • AS9100 and ISO 9001 certified facility • Full component traceability • Temperature cycling • Constant acceleration • 24, 96, 160 hour burn-in • Three level temperature screening Product# MQFL-28V-2R5S Phone 1-888-567-9596 DesigneD & ManufactureD in the usa featuring Qorseal® hi-rel asseMbly 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 and over-voltage shutdown Specification Compliance MQFL series converters (with MQME filter) are designed to meet: • MIL-HDBK-704-8 (A through F) • RTCA/DO-160 Section 16, 17, 18 • MIL-STD-1275 (B, D) • DEF-STAN 61-5 (part 6)/(5, 6) • MIL-STD-461 (C, D, E, F) • RTCA/DO-160(E, F, G) Section 22 www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 1 MQFL-28V-2R5S Output: 2.5V Current: 40A Technical Specification BLOCK DIAGRAM 1 INPUT RETURN 2 REGULATION STAGE BOOST CONVERTER SWITCHES AND CONTROL CURRENT SENSE CASE STABILITY GATE DRIVERS 3 CURRENT LIMIT UVLO ENABLE 1 4 SYNC OUT 5 SYNC IN 6 ISOLATION STAGE ISOLATION BARRIER +Vin +Vout 8 OUTPUT RETURN GATE DRIVERS MAGNETIC PRIMARY CONTROL 7 SECONDARY CONTROL DATA COUPLING 12 ENABLE 2 11 SHARE 10 + SENSE 9 − SENSE BIAS POWER CONTROL POWER TRANSFORMER TYPICAL CONNECTION DIAGRAM External bulk capacitor 28 Vdc + _ RSTABILITY CSTABILITY Product# MQFL-28V-2R5S open means on Phone 1-888-567-9596 1 +VIN 2 IN RTN 3 STABILITY 4 ENA 1 5 SYNC OUT 6 SYNC IN ENA 2 12 SHARE 11 MQFL www.SynQor.com +SNS 10 -SNS 9 open means on + Load OUT RTN 8 +VOUT 7 Doc.# 005-0005185 Rev. 3 06/03/15 _ Page 2 MQFL-28V-2R5S Output: 2.5V Current: 40A Technical Specification Under-Voltage Transient Profile Boost-Converter is armed (or re-armed) when Vin exceeds this value 20 VARM (~18V) Boost-Converter Operational Area 15 dV ≤ 0.1V μs dt VIN10 12.5V 5.5V 5 0 0 1.5 9 27 Time (s) Under-Voltage Transient Profile showing when the boost-converter is guaranteed to be operational. Before the boost converter will operate, it must first be armed (or re-armed) by making VIN greater than VARM. Note: This Under-Voltage Transient Profile is designed to comply (with appropriate margins) with all initial-engagement surges, starting or cranking voltage transients and under-voltage surges specified in: • MIL-STD-704-8 (A through F) • RTCA/DO-160 • MIL-STD-1275 • DEF-STAN 61-5 (part 6)/5 (operational portions) Product# MQFL-28V-2R5S Phone 1-888-567-9596 www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 3 MQFL-28V-2R5S Output: 2.5V Current: 40A Technical Specification MQFL-28V-2R5S ELECTRICAL CHARACTERISTICS Parameter Min. Typ. Max. Units Notes & Conditions Vin=28V dc ±5%, Iout=40A, CL=0µF, free running (see Note 10) boost-converter non-operational unless otherwise specified Specifications subject to change without notice ABSOLUTE MAXIMUM RATINGS Input Voltage Non-Operating Operating Reverse Bias (Tcase = 125ºC) Reverse Bias (Tcase = -55ºC) Isolation Voltage (I/O to case, I to O) Continuous Transient (≤100µs) Operating Case Temperature Storage Case Temperature Lead Temperature (20s) Voltage at ENA1, ENA2 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-Off Voltage Threshold Turn-On Voltage Threshold Shutdown Voltage Hysteresis Maximum Input Current No Load Input Current (operating) Disabled Input Current (ENA1) Disabled Input Current (ENA2) Input Terminal Current Ripple (pk-pk) OUTPUT CHARACTERISTICS Output Voltage Set Point (Tcase = 25ºC) Output Voltage Set Point Over Temperature Output Voltage Line Regulation Output Voltage Load Regulation Total Output Voltage Range Output Voltage Ripple and Noise Peak to Peak Operating Output Current Range Operating Output Power Range Output DC Current-Limit Inception Short Circuit Output Current Back-Drive Current Limit while Enabled Back-Drive Current Limit while Disabled Maximum Output Capacitance DYNAMIC CHARACTERISTICS Output Voltage Deviation Load Transient For a Pos. Step Change in Load Current For a Neg. Step Change in Load Current Settling Time (either case) Output Voltage Deviation Line Transient For a Pos. Step Change in Line Voltage For a Neg. Step Change in Line Voltage Settling Time (either case) Turn-On Transient Output Voltage Rise Time Output Voltage Overshoot Turn-On Delay, Rising Vin Turn-On Delay, Rising ENA1 Turn-On Delay, Rising ENA2 EFFICIENCY Iout = 40A (16Vin) Iout = 20A (16Vin) Iout = 40A (28Vin) Iout = 20A (28Vin) Iout = 40A (40Vin) Iout = 20A (40Vin) Load Fault Power Dissipation Short Circuit Power Dissipation Product# MQFL-28V-2R5S -500 -800 -55 -65 -1.2 60 60 -0.8 -1.2 V V V V 500 800 125 135 300 50 V V °C °C °C V 16 5.5 28 28 40 50 V V 14.75 13.80 0.50 15.50 14.40 1.10 16.00 15.00 1.80 V V V 54.0 50.0 2.0 56.8 51.4 5.3 60.0 54.0 8.0 8 160 5 50 120 V V V A mA mA mA mA 2.53 2.54 20 17 2.55 60 40 100 52 53 50 10,000 V V mV mV V mV A W A A A mA µF -300 300 200 450 350 mV mV µs 250 250 250 500 mV mV µs 6 0 5.5 3.0 1.5 10 2 8.0 6.0 3.0 ms % ms ms ms TBD TBD % % % % % % W W 110 2 25 80 2.47 2.46 -20 7 2.45 0 0 41 41 -450 -250 -250 2.50 2.50 0 12 2.50 15 46 47 13 10 TBD TBD TBD TBD TBD TBD Phone 1-888-567-9596 87 89 87 88 86 87 18 18 Group A Subgroup (see Note 13) See Note 1 HB Grade Products, See Notes 2 & 15 Continuous Transient, 1s; see Under-Voltage Transient Profile See Note 3 1, 2, 3 1, 2, 3 1, 2, 3 See Note 3 Vin = 16V; Iout = 40A See Note 5 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 Bandwidth = 100kHz – 10MHz; see Figure 14 Vout at sense leads “ “ “ ; Vout @ (Iout=0A) - Vout @ (Iout=40A) “ Bandwidth = 10MHz; CL=11µF 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 1, 2, 3 See Note 5 See Note 4 Vout ≤ 1.2V See Note 6 Total Iout step = 20A‹-›40A, 4A‹-›20A; CL=11µF “ See Note 7 Vin step = 16V‹-›50V; CL=11µF; see Note 8 “ “ See Note 7 4, 5, 6 4, 5, 6 Vout = 0.25V-›2.25V 4, 5, 6 See Note 5 4, 5, 6 4, 5, 6 4, 5, 6 ENA1, ENA2 = 5V; see Notes 9 & 12 ENA2 = 5V; see Note 12 ENA1 = 5V; see Note 12 1, 2, 3 Iout at current limit inception point; See Note 4 Vout ≤ 1.2V www.SynQor.com Doc.# 005-0005185 Rev. 3 1 1 06/03/15 Page 4 MQFL-28V-2R5S Output: 2.5V Current: 40A Technical Specification MQFL-28V-2R5S ELECTRICAL CHARACTERISTICS (Continued) Parameter Min. Typ. Max. Units Notes & Conditions Specifications subject to change without notice Vin=28V dc ±5%, Iout=40A, CL=0µF, free running (see Note 10) boostconverter non-operational unless otherwise specified Group A Subgroup (see Note 13) 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 (in rtn to out rtn) 100 MΩ 1 Isolation Resistance (any pin to case) 100 MΩ 1 Isolation Capacitance (in rtn to out rtn) 44 nF 1 FEATURE CHARACTERISTICS Switching Frequency (free running) 500 550 600 kHz 1, 2, 3 Synchronization Input Frequency Range 500 600 kHz 1, 2, 3 Logic Level High 2.0 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 other MQFL unit 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 Imax drawn from pin allowed, module on See Note 5 Pull-Up Voltage 3.2 4.0 4.5 V See Figure A 1, 2, 3 BOOST-CONVERTER OPERATION Input Voltage Arming Value 17.5 18.0 18.8 V 1, 2, 3 Switching Frequency 600 670 740 kHz 1 Input Terminal Current Ripple (RMS) 1 A Vin = 16V; Iout = 40A Total Converter Efficiency Iout = 15A (10Vin) 83 % 1 Iout = 15A (16Vin) 85 % Iout = 30A (16Vin) 85 % 1 RELIABILITY CHARACTERISTICS Calculated MTBF (MIL-STD-217F2) GB @ Tcase = 70ºC 2200 103 Hrs. AIF @ Tcase = 70ºC 390 103 Hrs. 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 = 135ºC (see Figure 5). 135ºC is above specified operating range. 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. SHARE pin outputs a power failure warning pulse during a fault condition. See Current Share section of the Control Features description. 12. After a disable or fault event, module is inhibited from restarting for 300ms. See Shut Down section of the Control Features description. 13. Only the ES and HB grade products are tested at three temperatures. The C- grade products are tested at one temperature. Please refer to the Construction and Environmental Stress Screening Options table for details. 14. These derating curves apply for the ES and HB grade products. The C- grade product has a maximum case temperature of 70ºC and a maximum junction temperature rise of 20ºC above Tcase. 15. The specified operating case temperature for ES grade products is -45ºC to 100ºC. The specified operating case temperature for C- grade products is 0ºC to 70ºC. Product# MQFL-28V-2R5S Phone 1-888-567-9596 www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 5 MQFL-28V-2R5S Output: 2.5V Current: 40A Application Section 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. In the MQFL-28V series of converters the regulation stage is preceeded by a boost-converter that permits these converters to operate through various Military and Aircraft under-voltage transients. Further discussion of this feature can be found later in these notes. 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. 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 opto-isolators 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 fold-back or fold-forward characteristic to the output current under this Product# MQFL-28V-2R5S Phone 1-888-567-9596 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. UNDER-VOLTAGE TRANSIENTS The MQFL-28V series of DC/DC converters incorporate a special “boost-converter” stage that permits the converters to deliver full power through transients where its input voltage falls to as low as 5.5V. Normally, the boost-converter is non-operational, and the converter’s input voltage is passed directly to its preregulation stage (see the Block Diagram). When an under-voltage transient occurs, the boost-converter becomes operational, and it steps-up the input voltage to a value greater than 16V so that the nominal output voltage can be sustained. It is important to note that the boost-converter stage must first become “armed” before it can become operational. This “arming” occurs when the converter’s input voltage exceeds approximately 18V. The boost-converter then becomes operational whenever the input voltage drops below the arming voltage, and it will remain operational as long as the input voltage remains within the region shown in the Under-Voltage Transient Profile Page. If the input voltage drops below this transient profile, the boost- converter stage is not guaranteed to continue operating (it may, but it will protect itself from excessive stresses). Once the boost- converter stops operating, the converter’s input voltage will be reconnected directly to the input of the pre-regulator stage. The output voltage will therefore collapse unless the input voltage is 16V, or greater. Note: the boost-converter will not become re-armed for the next transient unless the input voltage once again exceeds approximately 18V. The transient profile shown on the Under-Voltage Transient Profile page is designed to comply (with appropriate margins) with all initial-engagement surges, starting or cranking voltage transients, and under-voltage surges specified in: •MIL-STD-704-8(AthroughF) •RTCA/DO-160 •MIL-STD-1275 •DEF-STAN61-5(Part6)/5(operationalportions) Any input voltage transient that fits within the Under-Voltage Transient Profile can be repeated after a delay that is at least four times longer than the duration of the previous transient. During the time when the boost-converter stage is operational, the converter’s efficiency is reduced and the input ripple cur- www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 6 MQFL-28V-2R5S Output: 2.5V Current: 40A Application Section rent is increased. The lower the input voltage, the more these parameters are affected. mits the converter to be inhibited from either the input or the output side. Usually the converter has an EMI filter upstream of it, and the source voltage is connected to the input of this EMI filter. When, during compliance testing, the source voltage goes low during an under-voltage transient, the input to the converter will go even lower. This is because the inductance of the EMI filter (as well as the parasitic source inductance) will cause an oscillatory ring with the bulk capacitor. With the bulk capacitor that is present in an MQME-28 filter, the peak of this under-voltage ring may be approximately 2 volts if the source voltage drops to 6V (it will be smaller than this at a higher transient source voltage due to the lower current drawn by the converter). As a result, it is necessary to add extra bulk capacitor across the converter’s input pins if the source voltage is going to drop to 6V, as it does for MIL-STD-704(A) or MIL-STD-1275D. It is recommendedthata100μF/0.25WESRcapacitorbeconnected across the input pins of the converter be used as a starting point. For MIL-STD-704(B-F), where the source voltage drops toonly7V,a47μFhold-upcapacitorwouldbeagoodstarting point. The exact amount of capacitance required depends on the application (source induc- tance, load power, rate of fall of the source voltage, etc). Please consult the factory if further assistance is required. 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. Because input system stability is harder to maintain as the input voltage gets lower, the MQFL-28V series converters are designed to give external access to the voltage node between the boost-con- verter and the pre-regulator stages. This access, at the “STABILITY” pin (pin 3), permits the user to add a stabilizing bulk capacitor with series resistance to this node. Since the voltage at this node stays above 16V, the amount of capacitance required is much less than would be required on the converter’s input pins where the voltage might drop as low as 5.5V. It is recommendedthata22μFcapacitorwithanESRofabout1W be connected between the STABILITY pin and the INPUT RETURN pin (pin 2). Without this special connection to the internal node oftheconverter,a300μFstabilizingbulkcapacitorwouldhave been required across the converter’s input pins. Another advantage of the STABILITY pin is that it provides a volt- age source that stays above 16V when the under-voltage transient occurs. This voltage source might be useful for other circuitry in the system. 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. TheENA1pin(pin4)isreferencedwithrespecttotheconverter’s input return (pin 2). The ENA2 pin (pin 12) is referenced with respect to the converter’s output return (pin 8). This perProduct# MQFL-28V-2R5S Phone 1-888-567-9596 5.6V PIN 4 (OR PIN 12) 1N4148 82K TO ENABLE CIRCUITRY ENABLE 250K 2N3904 125K PIN 2 (OR PIN 8) IN RTN Figure A: Circuit diagram shown for reference only, actual circuit components may differ from values shown for equivalent circuit. 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. 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. 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. NOTE: Even if remote sensing of the load voltage is not desired, the +SENSE and the -SENSE pins must be connected to +Vout (pin7)andOUTPUTRETURN(pin8),respectively,togetproper www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 7 MQFL-28V-2R5S Output: 2.5V Current: 40A Application Section 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. Inside the converter, +SENSE is connected to +Vout with a resistor value from 100W to 301W, depending on output voltage, and –SENSE is connected to OUTPUT RETURN with a 10W 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. SYNCHRONIZATION: The MQFL converter’s regulation and isolation stage switching frequencies can be synchronized to an external frequency source that is in the 500 kHz to 600 kHz range.Theboost-converterstageisfree-runningatabout670 kHz while it is operational, and is not affected by synchronization signals. 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. 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. The SYNC OUT signal is available only when the voltage at the STABILITY pin (pin 3) 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. Product# MQFL-28V-2R5S Phone 1-888-567-9596 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. Figure B shows the equivalent circuit looking into the SYNC IN pin. Figure C shows the equivalent circuit looking into the SYNC OUT pin. 5V 5K PIN 6 PIN 2 SYNC IN TO SYNC CIRCUITRY 5K IN RTN Figure B: Equivalent circuit looking into the SYNC IN pin with respect to the IN RTN (input return) pin. 5V 5K SYNC OUT FROM SYNC CIRCUITRY IN RTN OPEN COLLECTOR OUTPUT PIN 5 PIN 2 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. 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. www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 8 MQFL-28V-2R5S Output: 2.5V Current: 40A Application Section 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: 407.5 Rtrim = 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 External bulk capacitor 28 Vdc + _ RSTABILITY CSTABILITY open means on 1 +VIN 2 IN RTN 3 STABILITY 4 ENA 1 5 SYNC OUT 6 SYNC IN 100,000 Trim Resistance (ohms) 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 14msastheoutputvoltagefalls. 10,000 1,000 100 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Increase in Vout (V) Figure E: Output Voltage Trim Graph 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. 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. This lockout only appears when the boost-converter is not operating. 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 unlessithasremainedinthatstateformorethanabout200μs. 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. ENA 2 12 SHARE 11 MQFL +SNS 10 -SNS 9 RTRIM _ OUT RTN 8 +VOUT 7 Load + Figure D: Typical connection for output voltage trimming. Product# MQFL-28V-2R5S Phone 1-888-567-9596 www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 9 MQFL-28V-2R5S Output: 2.5V Current: 40A Application Section 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 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. 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. 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. 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,amaximumtemperatureof145ºCispermissible,butnot 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. Product# MQFL-28V-2R5S Phone 1-888-567-9596 www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 10 MQFL-28V-2R5S Output: 2.5V Current: 40A Stress Screening CONSTRUCTION AND ENVIRONMENTAL STRESS SCREENING OPTIONS Consistent with MIL-STD-883F Screening C-Grade ES-Grade from ( specified 0 °C to +70 °C ) Element Evaluation HB-Grade from from ( -45specified ( -55specified °C to +100 °C ) °C to +125 °C ) No Yes Yes Yes Yes Internal Visual * Yes Temperature Cycle Method 1010 No Constant Acceleration Method 2001 (Y1 Direction) No 500g Condition A (5000g) Burn-in Method 1015 24 Hrs @ +125 °C 96 Hrs @ +125 °C 160 Hrs @ +125 °C Final Electrical Test Method 5005 (Group A) +25 °C -45, +25, +100 °C -55, +25, +125 °C Full QorSeal Full QorSeal Full QorSeal * Yes Yes QorSeal QorSeal QorSeal Mechanical Seal, Thermal, and Coating Process External Visual 2009 Construction Process Condition B Condition C (-55 °C to +125 °C) (-65 °C to +150 °C) * Per IPC-A-610 Class 3 MilQor converters and filters are offered in three variations of environmental stress screening options. All MilQor converters 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. 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 prequalifies each new batch of devices. Product# MQFL-28V-2R5S Phone 1-888-567-9596 www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 11 MQFL-28V-2R5S Output: 2.5V Current: 40A Technical Specifications MIL-STD-810F Qualification Testing MIL-STD-810F Test Fungus Method Description 508.5 Table 508.5-I 500.4 - Procedure I Storage: 70,000ft. / 2 Hr. duration 500.4 - Procedure II Operating; 70,000ft. / 2 Hr. duration; Ambient Temperature Rapid Decompression 500.4 - Procedure III Storage: 8,000ft. to 40,000ft. Acceleration 513.5 - Procedure II Operating - 15g’s Salt Fog 509.4 Storage 501.4 - Procedure I Storage: 135°C / 3 hrs 501.4 - Procedure II Operating: 100°C / 3 hrs 502.4 - Procedure I Storage: -65°C / 4 hrs 502.4 - Procedure II Operating: -55°C / 3 hrs Altitude High Temperature Low Temperature Temperature Shock 503.4 - Procedure I - C Storage: -65°C to 135°C; 12 cycles Rain 506.4 - Procedure I Wind Blown Rain Immersion 512.4 - Procedure I Non-Operating Humidity 507.4 - Procedure II Random Vibration 514.5 - Procedure I 10-2000 Hz, PSD level of 1.5 g2/Hz(54.6grms), duration = 1 hr/axis 516.5 - Procedure I 20g’s peak, 11ms, Functional Shock (Operating no load) (saw tooth) 516.5 - Procedure VI Bench Handling Shock Shock Sinusoidal vibration Sand and Dust Product# MQFL-28V-2R5S 514.5 - Category 14 Aggravated cycle @ 95% RH (Figure 507.5-7 aggravated temp humidity cycle, 15 cycles) Rotary wing aircraft - helicopter, 4hrs/axis, 20g’s (sine sweep from 10 500HZ) 510.4 - Procedure I Blowing Dust 510.4 - Procedure II Blowing Sand Phone 1-888-567-9596 www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 12 MQFL-28V-2R5S Output: 2.5V Current: 40A Technical Specifications First Article Testing consistent with MIL-STD-883F MIL-STD-883F Test Method Description Electrical Tests 5005 Physical Dimensions test 2016 Resistance to Solvents test 2015.13 Solderability test 2003.8 Lead Integrity test 2004.5 Salt Atmosphere test 1009.8 Adhesion of Lead Finish test 2025.4 Altitude Operation test 1001 Condition “C” ESD Sensitivity 3015.7 Class 2 Stabilization Bake test 1008.2 Condition “C” Vibration Fatigue test 2005.2 Condition “A” Random Vibration test 2026 Condition “II K” Condition “A” Sequential Test Group #1 Life Test – Steady State test 1005.8 Life Test – Intermittent Duty test 1006 Sequential Test Group #2 Temperature Cycle test 1010.8 Condition “C” Constant Acceleration test 2001.2 Condition “A” Thermal Shock test 1011.9 Condition “B” Temperature Cycle test 1010.8 Condition “C” Moisture Resistance test 1004.7 With Sub cycle Mechanical Shock test 2002.4 Condition “B” Variable Frequency Vibration test 2007.3 Condition “A” Sequential Test Group #3 Sequential Test Group #4 Product# MQFL-28V-2R5S Phone 1-888-567-9596 www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 13 MQFL-28V-2R5S Output: 2.5V Current: 40A Mechanical Diagrams 1 2 3 4 5 6 SEE NOTE 7 +VIN IN RTN SHARE STABILITY MQFL-28V-2R5S-X-ES +SNS DC-DC ConVERtER 28Vin 2.5Vout @ 40A ENA 1 -SNS SYNC OUT SYNC IN 12 11 10 9 8 7 ENA 2 MADE IN USA OUT RTN S/N 0000000 D/C 3205-301 CAGE 1WX10 +VOUT 0.250 [6.35] 1.50 [38.1] 0.040 [1.02] PIN 2.50 [63.50] 2.760 [70.10] 3.00 [76.2] 0.22 [5.6] 0.228 [5.79] 0.390 [9.91] SEE NOTE 7 6 +VIN ENA 2 IN RTN STABILITY SHARE MQFL-28V-2R5S-U-ES +SNS DC-DC ConVERtER 28Vin 2.5Vout @ 40A ENA 1 SYNC OUT SYNC IN 0.050 [1.27] 0.128 [3.25] 2.96 [75.2] 1 2 3 4 5 0.200 [5.08] TYP. NON-CUM. 1.260 [32.00] -SNS MADE IN USA S/N 0000000 D/C 3211-301 CAGE 1WX10 OUT RTN +VOUT 12 11 10 9 8 7 2.50 [63.5] 2.760 [70.10] 3.00 [76.2] Case X 0.250 [6.35] 0.200 [5.08] TYP. NON-CUM. 1.50 [38.1] 1.260 [32.00] 0.040 [1.02] PIN 0.050 [1.27] 0.42 [10.7] 0.128 [3.25] 0.22 [5.6] 2.80 [71.1] 0.390 [9.91] PIN DESIGNATIONS NOTES 1) 2) 3) 4) 5) 6) 7) 8) Pins 0.040’’ (1.02mm) diameter Pin Material: Copper Alloy Finish: Gold over Nickel plating, followed by Sn/Pb solder dip 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-610 Class III Print Labeling on Top Surface per Product Label Format Drawing Pin 1 identification hole, not intended for mounting (case X and U) Baseplate flatness tolerance is 0.004” (.10mm) TIR for surface. Product# MQFL-28V-2R5S Case U Phone 1-888-567-9596 www.SynQor.com Pin # Function 1 2 3 4 5 6 Pin # Function Positive input Input return Stability Enable 1 Sync output Sync input Doc.# 005-0005185 Rev. 3 7 8 9 10 11 12 Positive output Output return - Sense + Sense Share Enable 2 06/03/15 Page 14 MQFL-28V-2R5S Output: 2.5V Current: 40A Mechanical Diagrams 0.300 [7.62] 0.140 [3.56] 1.150 [29.21] 0.250 [6.35] TYP 1 2 3 4 5 6 +VIN ENA 2 IN RTN SHARE MQFL-28V-2R5S-Y-ES STABILITY ENA 1 -SNS SYNC OUT SYNC IN +SNS DC-DC ConVERtER 28Vin 2.5Vout @ 40A MADE IN USA S/N 0000000 D/C 3211-301 CAGE 1WX10 OUT RTN +VOUT 1.750 [44.45] 12 2.000 11 [50.80] 10 1.50 9 [38.1] 8 1.750 7 [44.45] 0.250 [6.35] 0.200 [5.08] TYP. NON-CUM. 0.040 [1.02] PIN 0.050 [1.27] 0.22 [5.6] 0.375 [9.52] 2.50 [63.5] 2.96 [75.2] 0.228 [5.79] 0.390 [9.91] Case Y 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 0.22 [5.6] 0.050 [1.27] 0.42 [10.7] 0.36 [9.14] 0.050 [1.27] 0.22 [5.6] 2.80 [71.1] 0.525 [13.33] 0.390 [9.91] 0.525 [13.33] 0.390 [9.91] 2.80 [71.1] PIN DESIGNATIONS NOTES 1) 2) 3) 4) 5) 6) 7) 8) Pins 0.040’’ (1.02mm) diameter Pin Material: Copper Alloy Finish: Gold over Nickel plating, followed by Sn/Pb solder dip 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-610 Class III Print Labeling on Top Surface per Product Label Format Drawing Pin 1 identification hole, not intended for mounting (case X and U) Baseplate flatness tolerance is 0.004” (.10mm) TIR for surface. Product# MQFL-28V-2R5S Phone 1-888-567-9596 www.SynQor.com Pin # Function 1 2 3 4 5 6 Pin # Function Positive input Input return Stability Enable 1 Sync output Sync input Doc.# 005-0005185 Rev. 3 7 8 9 10 11 12 Positive output Output return - Sense + Sense Share Enable 2 06/03/15 Page 15 MQFL-28V-2R5S Output: 2.5V Current: 40A Ordering Information MilQor Converter FAMILY MATRIX The tables below show the array of MilQor 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 Full Size MQFL-28 16-40Vin Cont. 16-50Vin 1s Trans.* Dual 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) 5V (05D) 12V (12D) 15V (15D) 40A 40A 40A 30A 24A 20A 16A 13A 10A 8A 4A 24A Total 10A Total 8A Total 40A 40A 40A 30A 24A 20A 16A 13A 10A 8A 4A 24A Total 10A Total 8A Total 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 24A Total 10A Total 8A Total 40A 40A 30A 22A 15A 12A 10A 8A 6A 5A 2.7A 15A Total 6A Total 5A Total 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) 5V (05D) 12V (12D) 15V (15D) 20A 20A 20A 15A 10A 8A 6.6A 5.5A 4A 3.3A 1.8A 10A Total 4A Total 3.3A Total 20A 20A 20A 15A 10A 8A 6.6A 5.5A 4A 3.3A 1.8A 10A Total 4A Total 3.3A Total 10A 10A 10A 7.5A 5A 4A 3.3A 2.75A 2A 1.65A 0.9A 5A Total 2A Total 1.65A Total 10A 10A 10A 7.5A 5A 4A 3.3A 2.75A 2A 1.65A 0.9A 5A Total 2A Total 1.65A Total 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 1s Trans.* Absolute Max Vin = 550V MQFL-270L 65-350Vin Cont. 65-475Vin 1s Trans.* Absolute Max Vin = 550V Single Output Half Size MQHL-28 16-40Vin Cont. 16-50Vin 1s Trans.* Dual Output † Absolute Max Vin = 60V MQHL-28E 16-70Vin Cont. 16-80Vin 1s Trans.* Absolute Max Vin =100V MQHR-28 16-40Vin Cont. 16-50Vin 1s Trans.* Absolute Max Vin = 60V MQHR-28E 16-70Vin Cont. 16-80Vin 1s Trans.* Absolute Max Vin = 100V Check with factory for availability. †80% of total output current available on any one output. *Converters may be operated at the highest transient input voltage, but some component electrical and thermal stresses would be beyond MILHDBK-1547A guidelines. Product# MQFL-28V-2R5S Phone 1-888-567-9596 www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 16 MQFL-28V-2R5S Output: 2.5V Current: 40A Ordering Information PART NUMBERING SYSTEM The part numbering system for SynQor’s MilQor DC-DC converters follows the format shown in the table below. Not all combinations make valid part numbers, please contact SynQor for availability. See the Product Summary web page for more options. Example: Input Voltage Range Model Name 28 28E 28V 28VE MQFL MQHL MQHR 270 270L MQFL-28V-2R5S-Y-ES Output Voltage(s) Single Output Dual Output 1R5S 1R8S 2R5S 3R3S 05S 06S 7R5S 09S 12S 15S 28S 05D 12D 15D Package Outline/ Pin Configuration Screening Grade U X Y W Z C ES HB APPLICATION NOTES A variety of application notes and technical white papers can be downloaded in pdf format from the SynQor website. Contact SynQor for further information and to order: Phone: Toll Free: Fax: E-mail: Web: Address: Product# MQFL-28V-2R5S 978-849-0600 1-888-567-9596 978-849-0602 [email protected] www.synqor.com 155 Swanson Road Boxborough, MA 01719 USA Phone 1-888-567-9596 PATENTS 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 Warranty SynQor offers a two (2) year limited warranty. Complete warranty information is listed on our website or is available upon request from SynQor. www.SynQor.com Doc.# 005-0005185 Rev. 3 06/03/15 Page 17