Data Sheet April 2008 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Features n The QW Series Power Modules use advanced, surface-mount technology and deliver high-quality, efficient, and compact dc-dc conversion. Applications n High power density n High efficiency: 84% typical n Low output noise n Constant frequency n Industry-standard pinout n Metal baseplate n 2:1 input voltage range n Overvoltage and overcurrent protection n Remote on/off n Remote sense n Adjustable output voltage n Overtemperature protection ISO* 9001 Certified manufacturing facilities n Distributed power architectures n n Workstations n n Computer equipment n Communications equipment Options n Heat sinks available for extended operation n Auto-restart after overcurrent shutdown Small size: 36.8 mm x 57.9 mm x 12.7 mm (1.45 in. x 2.28 in. x 0.50 in.) n UL1950 Recognized, CSA C22.2 No. 950-95 Certified, and VDE 0805 (EN60950, IEC950) Licensed CE mark meets 73/23/EEC and 93/68/EEC directives** * ISO is a registered trademark of the International Organization for Standardization. UL is a registered trademark of Underwriters Laboratories, Inc. CSA is a registered trademark of Canadian Standards Association. VDE is a trademark of Verband Deutscher Elektrotechniker e.V. ** This product is intended for integration into end-use equipment. All the required procedures for CE marking of end-use equipment should be followed. (The CE mark is placed on selected products.) Description The QW050A1 and QW075A1 Power Modules are dc-dc converters that operate over an input voltage range of 36 Vdc to 75 Vdc and provide a precisely regulated dc output. The outputs are fully isolated from the inputs, allowing versatile polarity configurations and grounding connections. The modules have maximum power ratings from 50 W to 75 W at a typical full-load efficiency of 84%. The sealed modules offer a metal baseplate for excellent thermal performance. Threaded-through holes are provided to allow easy mounting or addition of a heat sink for high-temperature applications. The standard feature set includes remote sensing, output trim, and remote on/off for convenient flexibility in distributed power applications. QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Data Sheet April 2008 Absolute Maximum Ratings Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are absolute stress ratings only. Functional operation of the device is not implied at these or any other conditions in excess of those given in the operations sections of the data sheet. Exposure to absolute maximum ratings for extended periods can adversely affect device reliability. Parameter Symbol Min Max Unit VI VI, trans -- -- 75 100 Vdc V Operating Case Temperature (See Thermal Considerations section; see Figure 22.) TC -40 100 C Storage Temperature Tstg -55 125 C I/O Isolation Voltage (for 1 minute) -- -- 1500 Vdc Input Voltage: Continuous Transient (100 ms) Electrical Specifications Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature conditions. Table 1. Input Specifications Parameter Symbol Min Typ Max Unit VI 36 48 75 Vdc II, max II, max -- -- -- -- 2.5 3.5 A A Inrush Transient i 2t -- -- 1.3 A2s Input Reflected-ripple Current, Peak-to-peak (5 Hz to 20 MHz, 12 H source impedance; see Figure 13.) II -- 10 -- mAp-p Input Ripple Rejection (120 Hz) -- -- 60 -- dB Operating Input Voltage Maximum Input Current (VI = 0 V to 75 V; IO = IO, max; see Figures 1 and 2): QW050A1 QW075A1 Fusing Considerations CAUTION: This power module is not internally fused. An input line fuse must always be used. This encapsulated power module can be used in a wide variety of applications, ranging from simple stand-alone operation to an integrated part of a sophisticated power architecture. To preserve maximum flexibility, internal fusing is not included; however, to achieve maximum safety and system protection, always use an input line fuse. The safety agencies require a normal-blow fuse with a maximum rating of 3 A (see Safety Considerations section). Based on the information provided in this data sheet on inrush energy and maximum dc input current, the same type of fuse with a lower rating can be used. Refer to the fuse manufacturer's data for further information. 2 Lineage Power Data Sheet April 2008 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Electrical Specifications (continued) Table 2. Output Specifications Parameter Device Symbol Min Typ Max Unit Output Voltage Set Point (VI = 48 V; IO = IO, max; TC = 25 C) All VO, set 4.92 5.0 5.08 Vdc Output Voltage (Over all operating input voltage, resistive load, and temperature conditions until end of life. See Figure 15.) All VO 4.85 -- 5.15 Vdc Output Regulation: Line (VI = 36 V to 75 V) Load (IO = IO, min to IO, max) Temperature (TC = -40 C to +100 C) All All All -- -- -- -- -- -- 0.01 0.05 15 0.1 0.2 50 %VO %VO mV Output Ripple and Noise Voltage (See Figure 14.): RMS Peak-to-peak (5 Hz to 20 MHz) All All -- -- -- -- -- -- 40 150 mVrms mVp-p All -- 0 -- * F Output Current (At IO < IO, min, the modules may exceed output ripple specifications.) External Load Capacitance QW050A1 QW075A1 IO IO 0.5 0.5 -- -- 10 15 A A Output Current-limit Inception (VO = 90% of VO, nom) QW050A1 QW075A1 IO, cli IO, cli -- -- 15 20 20 26 A A Efficiency (VI = 48 V; IO = IO, max; TC = 70 C) QW050A1 QW075A1 -- -- 84 84 -- -- % % All -- -- 380 -- kHz All All -- -- -- -- 5 700 -- -- %VO, set s All All -- -- -- -- 5 700 -- -- %VO, set s Switching Frequency Dynamic Response (yIO/yt = 1 A/10 s, VI = 48 V, TC = 25 C; tested with a 1000 F aluminum and a 1.0 F ceramic capacitor across the load.): Load Change from IO = 50% to 75% of IO, max: Peak Deviation Settling Time (VO < 10% of peak deviation) Load Change from IO = 50% to 25% of IO, max: Peak Deviation Settling Time (VO < 10% of peak deviation) * Consult your sales representative or the factory. These are manufacturing test limits. In some situations, results may differ. Table 3. Isolation Specifications Parameter Min Typ Max Unit Isolation Capacitance -- 2500 -- pF Isolation Resistance 10 -- -- M3/4 Lineage Power 3 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Data Sheet April 2008 General Specifications Parameter Min Calculated MTBF (IO = 80% of IO, max; TC = 40 C): QW050A1 QW075A1 Weight Typ Max Unit 4,000,000 3,500,000 -- hours hours -- 75 (2.7) g (oz.) Feature Specifications Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature conditions. See Feature Descriptions for additional information. Parameter Remote On/Off Signal Interface (VI = 0 V to 75 V; open collector or equivalent compatible; signal referenced to VI(-) terminal; see Figure 16 and Feature Descriptions.): Logic Low--Module On Logic High--Module Off Logic Low: At Ion/off = 1.0 mA At Von/off = 0.0 V Logic High: At Ion/off = 0.0 A Leakage Current Turn-on Time (See Figures 11 and 12.) (IO = 80% of IO, max; VO within 1% of steady state) Output Voltage Adjustment (See Feature Descriptions.): Output Voltage Remote-sense Range Output Voltage Set-point Adjustment Range (trim) Output Overvoltage Protection Overtemperature Protection Symbol Min Typ Max Unit Von/off Ion/off 0 -- -- -- 1.2 1.0 V mA Von/off Ion/off -- -- -- -- -- -- 20 15 50 35 V A ms -- -- -- 60 -- -- 0.5 110 V %VO, nom VO, sd 5.7* -- 6.8* V TC -- 105 -- C * These are manufacturing test limits. In some situations, results may differ. Solder, Cleaning, and Drying Considerations Post solder cleaning is usually the final circuit-board assembly process prior to electrical testing. The result of inadequate circuit-board cleaning and drying can affect both the reliability of a power module and the testability of the finished circuit-board assembly. For guidance on appropriate soldering, cleaning, and drying procedures, refer to the Board-Mounted Power Modules Soldering and Cleaning Application Note (AP97-021EPS). 4 Lineage Power Data Sheet April 2008 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Characteristic Curves The following figures provide typical characteristics for the power modules. The figures are identical for both on/off configurations. 2.5 85 83 EFFICIENCY, (%) INPUT CURRENT, II (A) 84 2.0 IO = 10 A IO = 6 A IO = 1 A 1.5 1.0 82 81 80 79 78 0.5 77 0.0 76 75 20 25 30 35 40 45 50 55 60 65 70 75 VI = 36 V VI = 48 V VI = 75 V 2 3 4 INPUT VOLTAGE, VI (V) 5 6 7 8 9 10 OUTPUT CURRENT, IO (A) 8-2949 (F) Figure 1. Typical QW050A1 Input Characteristics at Room Temperature 8-2950 (F) Note: Pending improvement will add 1% to the above curves. Figure 3. Typical QW050A1 Converter Efficiency vs. Output Current at Room Temperature 3.5 85 84 IO = 15 A IO = 7.5 A IO = 1.5 A 2.5 83 EFFICIENCY, (%) INPUT CURRENT, II (A) 3.0 2.0 1.5 1.0 0.5 82 81 80 VI = 36 V VI = 54 V VI = 75 V 79 78 77 0.0 20 25 30 35 40 45 50 55 60 65 70 75 76 75 INPUT VOLTAGE, V I (V) 8-2327 (C) Figure 2. Typical QW075A1 Input Characteristics at Room Temperature 3 4 5 6 7 8 9 10 11 12 13 14 15 OUTPUT CURRENT, IO (A) 8-2951 (F) Note: Pending improvement will add 1% to the above curves. Figure 4. Typical QW075A1 Converter Efficiency vs. Output Current at Room Temperature Lineage Power 5 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Data Sheet April 2008 OUTPUT VOLTAGE, VO (V) (100 mV/div) Characteristic Curves (continued) VI = 54 V OUTPUT CURRENT, IO (A) (1 A/div) OUTPUT VOLTAGE, VO (V) (50 mV/div) VI = 75 V VI = 36 V 5A 2.5 A TIME, t (500 s/div) 8-2952 (F) Note: Tested with a 1000 F aluminum and a 1.0 F ceramic capacitor across the load. TIME, t (1 s/div) 8-2062 (C) Figure 5. Typical QW050A1 Output Ripple Voltage at Room Temperature and IO = IO, max Figure 7. Typical QW050A1 Transient Response to Step Decrease in Load from 50% to 25% of IO, max at Room Temperature and 54 Vdc Input (Waveform Averaged to Eliminate Ripple Component.) OUTPUT VOLTAGE, VO (V) (100 mV/div) VI = 54 V OUTPUT CURRENT, IO (A) (1 A/div) OUTPUT VOLTAGE, VO (V) (50 mV/div) VI = 75 V VI = 36 V TIME, t (1 s/div) 3.75 A TIME, t (200 ns/div) 8-2298 (C) Note: See Figure 14 for test conditions. Figure 6. Typical QW075A1 Output Ripple Voltage at Room Temperature and IO = IO, max 6 7.5 A 8-2953 (F) Note: Tested with a 1000 F aluminum and a 1.0 F ceramic capacitor across the load. Figure 8. Typical QW075A1 Transient Response to Step Decrease in Load from 50% to 25% of IO, max at Room Temperature and 54 Vdc Input (Waveform Averaged to Eliminate Ripple Component.) Lineage Power Data Sheet April 2008 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W OUTPUT VOLTAGE, VO (V) (2 V/div) OUTPUT CURRENT, IO (A) (1 A/div) OUTPUT VOLTAGE, VO (V) (100 mV/div) REMOTE, ON/OFF VON/OFF (V) Characteristic Curves (continued) 7.5 A 5.0 A TIME, t (5 ms/div) TIME, t (500 s/div) 8-3027 (F) 8-2954 (F) Note: Tested with a 1000 F aluminum and a 1.0 F ceramic capacitor across the load. OUTPUT VOLTAGE, VO (V) (1 V/div) OUTPUT VOLTAGE, VO (V) (100 mV/div) 11.25 A OUTPUT CURRENT, IO (A) (1 A/div) Figure 11. QW050A1 Typical Start-Up from Remote On/Off; IO = IO, max REMOTE ON/OFF, VON/OFF (V) Figure 9. Typical QW050A1 Transient Response to Step Increase in Load from 50% to 75% of IO, max at Room Temperature and 54 Vdc Input (Waveform Averaged to Eliminate Ripple Component.) Note: Tested with a 1000 F aluminum and a 1.0 F ceramic capacitor across the load. 7.5 A TIME, t (2 ms/div) 8-2956 (F) TIME, t (200 s/div) 8-2955 (F) Note: Tested with a 220 F aluminum and a 1.0 F ceramic capacitor across the load. Figure 10. Typical QW075A1 Transient Response to Step Increase in Load from 50% to 75% of IO, max at Room Temperature and 54 Vdc Input (Waveform Averaged to Eliminate Ripple Component.) Lineage Power Note: Tested with a 1000 F aluminum and a 1.0 F ceramic capacitor across the load. Figure 12. QW075A1 Typical Start-Up from Remote On/Off; IO = IO, max 7 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Test Configurations Data Sheet April 2008 Design Considerations Input Source Impedance TO OSCILLOSCOPE CURRENT PROBE LTEST VI(+) 12 H CS 220 F ESR < 0.1 @ 20 C, 100 kHz BATTERY 33 F ESR < 0.7 @ 100 kHz VI(-) 8-203 (C).l Note: Measure input reflected-ripple current with a simulated source inductance (LTEST) of 12 H. Capacitor CS offsets possible battery impedance. Measure current as shown above. Figure 13. Input Reflected-Ripple Test Setup COPPER STRIP V O (+) 1.0 F 10 F RESISTIVE LOAD SCOPE V O (-) 8-513 (C).d Note: Use a 1.0 F ceramic capacitor and a 10 F aluminum or tantalum capacitor. Scope measurement should be made using a BNC socket. Position the load between 51 mm and 76 mm (2 in. and 3 in.) from the module. The power module should be connected to a low ac-impedance input source. Highly inductive source impedances can affect the stability of the power module. For the test configuration in Figure 13, a 33 F electrolytic capacitor (ESR < 0.7 3/4 at 100 kHz) mounted close to the power module helps ensure stability of the unit. For other highly inductive source impedances, consult the factory for further application guidelines. Safety Considerations For safety-agency approval of the system in which the power module is used, the power module must be installed in compliance with the spacing and separation requirements of the end-use safety agency standard, i.e., UL1950, CSA C22.2 No. 950-95, and VDE 0805 (EN60950, IEC950). If the input source is non-SELV (ELV or a hazardous voltage greater than 60 Vdc and less than or equal to 75 Vdc), for the module's output to be considered meeting the requirements of safety extra-low voltage (SELV), all of the following must be true: n n Figure 14. Peak-to-Peak Output Noise Measurement Test Setup n n SENSE(+) VI(+) CONTACT AND DISTRIBUTION LOSSES VO(+) IO II LOAD SUPPLY VI(-) CONTACT RESISTANCE One VI pin and one VO pin are to be grounded, or both the input and output pins are to be kept floating. The input pins of the module are not operator accessible. Another SELV reliability test is conducted on the whole system, as required by the safety agencies, on the combination of supply source and the subject module to verify that under a single fault, hazardous voltages do not appear at the module's output. Note: Do not ground either of the input pins of the module without grounding one of the output pins. This may allow a non-SELV voltage to appear between the output pin and ground. VO(-) SENSE(-) 8-749 (C) Note: All measurements are taken at the module terminals. When socketing, place Kelvin connections at module terminals to avoid measurement errors due to socket contact resistance. [ V O (+) - V O (-) ]I O = ------------------------------------------------ x 100 [ V I (+) - V I (-) ]I I The input source is to be provided with reinforced insulation from any hazardous voltages, including the ac mains. % Figure 15. Output Voltage and Efficiency Measurement Test Setup 8 The power module has extra-low voltage (ELV) outputs when all inputs are ELV. The input to these units is to be provided with a maximum 3 A normal-blow fuse in the ungrounded lead. Lineage Power Data Sheet April 2008 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Feature Descriptions Overcurrent Protection To provide protection in a fault (output overload) condition, the unit is equipped with internal current-limiting circuitry and can endure current limiting for up to one second. If overcurrent exists for more than one second, the unit will shut down. At the point of current-limit inception, the unit shifts from voltage control to current control. If the output voltage is pulled very low during a severe fault, the currentlimit circuit can exhibit either foldback or tailout characteristics (output current decrease or increase). The module is available in two overcurrent configurations. In one configuration, when the unit shuts down it will latch off. The overcurrent latch is reset by either cycling the input power or by toggling the ON/OFF pin for one second. In the other configuration, the unit will try to restart after shutdown. If the output overload condition still exists when the unit restarts, it will shut down again. This operation will continue indefinitely until the overcurrent condition is corrected. Remote On/Off Negative logic remote on/off turns the module off during a logic high and on during a logic low. To turn the power module on and off, the user must supply a switch to control the voltage between the on/off terminal and the VI(-) terminal (Von/off). The switch can be an open collector or equivalent (see Figure 16). A logic low is Von/off = 0 V to 1.2 V. The maximum Ion/off during a logic low is 1 mA. The switch should maintain a logiclow voltage while sinking 1 mA. During a logic high, the maximum Von/off generated by the power module is 15 V. The maximum allowable leakage current of the switch at Von/off = 15 V is 50 A. If not using the remote on/off feature, short the ON/OFF pin to VI(-). Ion/off + ON/OFF Von/off - SENSE(+) VO(+) LOAD VI(+) VI(-) VO(-) SENSE(-) 8-720 (C).c Figure 16. Remote On/Off Implementation Remote Sense Remote sense minimizes the effects of distribution losses by regulating the voltage at the remote-sense connections. The voltage between the remote-sense pins and the output terminals must not exceed the output voltage sense range given in the Feature Specifications table, i.e.: [VO(+) - VO(-)] - [SENSE(+) - SENSE(-)] 0.5 V The voltage between the VO(+) and VO(-) terminals must not exceed the minimum output overvoltage protection value shown in the Feature Specifications table. This limit includes any increase in voltage due to remote-sense compensation and output voltage setpoint adjustment (trim). See Figure 17. If not using the remote-sense feature to regulate the output at the point of load, then connect SENSE(+) to VO(+) and SENSE(-) to VO(-) at the module. Although the output voltage can be increased by both the remote sense and by the trim, the maximum increase for the output voltage is not the sum of both. The maximum increase is the larger of either the remote sense or the trim. Consult the factory if you need to increase the output voltage more than the above limitation. The amount of power delivered by the module is defined as the voltage at the output terminals multiplied by the output current. When using remote sense and trim, the output voltage of the module can be increased, which at the same output current would increase the power output of the module. Care should be taken to ensure that the maximum output power of the module remains at or below the maximum rated power. Lineage Power 9 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Data Sheet April 2008 Feature Descriptions (continued) remote-sense compensation and output voltage setpoint adjustment (trim). See Figure 17. Remote Sense (continued) Although the output voltage can be increased by both the remote sense and by the trim, the maximum increase for the output voltage is not the sum of both. The maximum increase is the larger of either the remote sense or the trim. Consult the factory if you need to increase the output voltage more than the above limitation. SENSE(+) SENSE(-) VI(+) SUPPLY VO(+) IO II VI(-) LOAD VO(-) CONTACT AND DISTRIBUTION LOSSES CONTACT RESISTANCE 8-651 (C).m Figure 17. Effective Circuit Configuration for Single-Module Remote-Sense Operation Output Voltage Set-Point Adjustment (Trim) The amount of power delivered by the module is defined as the voltage at the output terminals multiplied by the output current. When using remote sense and trim, the output voltage of the module can be increased, which at the same output current would increase the power output of the module. Care should be taken to ensure that the maximum output power of the module remains at or below the maximum rated power. VI(+) Output voltage trim allows the user to increase or decrease the output voltage set point of a module. This is accomplished by connecting an external resistor between the TRIM pin and either the SENSE(+) or SENSE(-) pins. The trim resistor should be positioned close to the module. ON/OFF CASE VI(-) k The test results for this configuration are displayed in Figure 19. This figure applies to all output voltages. With an external resistor connected between the TRIM and SENSE(+) pins (Radj-up), the output voltage set point (VO, adj) increases (see Figure 20). The following equation determines the required external-resistor value to obtain a percentage output voltage change of y%. 5.1V O ( 100 + % ) 510 - - ---------- - 10.2 k R adj-up = --------------------------------------------- % 1.225% The test results for this configuration are displayed in Figure 21. The voltage between the VO(+) and VO(-) terminals must not exceed the minimum output overvoltage protection value shown in the Feature Specifications table. This limit includes any increase in voltage due to 10 RLOAD TRIM SENSE(-) VO(-) 8-748 (C).b Figure 18. Circuit Configuration to Decrease Output Voltage ADJUSTMENT RESISTOR VALUE () 510 R adj-down = ---------- - 10.2 % SENSE(+) Radj-down If not using the trim feature, leave the TRIM pin open. With an external resistor between the TRIM and SENSE(-) pins (Radj-down), the output voltage set point (VO, adj) decreases (see Figure 18). The following equation determines the required external-resistor value to obtain a percentage output voltage change of y%. VO(+) 1M 100k 10k 1k 0 10 20 30 40 % CHANGE IN OUTPUT VOLTAGE ( %) 8-2577 (C) Figure 19. Resistor Selection for Decreased Output Voltage Lineage Power Data Sheet April 2008 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Feature Descriptions (continued) Overtemperature Protection Output Voltage Set-Point Adjustment (Trim) (continued) These modules feature an overtemperature protection circuit to safeguard against thermal damage. The circuit shuts down and latches off the module when the maximum case temperature is exceeded. The module can be restarted by cycling the dc input power for at least 1.0 second or by toggling the remote on/off signal for at least 1.0 second. VO (+) VI (+) SENSE(+) ON/OFF Radj-up CASE RLOAD TRIM Thermal Considerations SENSE(-) VI (-) Introduction VO(-) 8-715 (C).b ADJUSTMENT RESISTOR VALUE () Figure 20. Circuit Configuration to Increase Output Voltage 10M The power modules operate in a variety of thermal environments; however, sufficient cooling should be provided to help ensure reliable operation of the unit. Heat-dissipating components inside the unit are thermally coupled to the case. Heat is removed by conduction, convection, and radiation to the surrounding environment. Proper cooling can be verified by measuring the case temperature. Peak temperature (TC) occurs at the position indicated in Figure 22. 33 (1.30) 1M 14 (0.55) VI(+) ON/OFF VI(-) 100k 0 2 4 6 8 10 8-2104 (C) % CHANGE IN OUTPUT VOLTAGE ( %) 8-2855 (F) Figure 21. Resistor Selection for Increased Output Voltage Output Overvoltage Protection The output overvoltage protection consists of circuitry that monitors the voltage on the output terminals. If the voltage on the output terminals exceeds the overvoltage protection threshold, then the module will shut down and latch off. The overvoltage latch is reset by either cycling the input power for 1.0 second or by toggling the on/off signal for 1.0 second. Lineage Power VO(+) (+)SENSE TRIM (-)SENSE VO(-) Note: Top view, pin locations are for reference only. Measurements shown in millimeters and (inches). Figure 22. Case Temperature Measurement Location The temperature at this location should not exceed 100 C. The output power of the module should not exceed the rated power for the module as listed in the Ordering Information table. Although the maximum case temperature of the power modules is 100 C, you can limit this temperature to a lower value for extremely high reliability. 11 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Thermal Considerations (continued) Note that the natural convection condition was measured at 0.05 m/s to 0.1 m/s (10 ft./min. to 20 ft./min.); however, systems in which these power modules may be used typically generate natural convection airflow rates of 0.3 m/s (60 ft./min.) due to other heat dissipating components in the system. The use of Figure 25 is shown in the following example. Example What is the minimum airflow necessary for a QW050A1 operating at VI = 54 V, an output current of 10 A, and a maximum ambient temperature of 40 C? Solution Given: VI = 54 V IO = 10 A TA = 40 C Determine PD (Use Figure 23.): PD = 10 W Determine airflow (v) (Use Figure 25.): v = 1.25 m/s (250 ft./min.) Note: Pending improvement will lower the power dissipation and reduce the airflow needed. POWER DISSIPATION, PD (W) Increasing airflow over the module enhances the heat transfer via convection. Figure 25 shows the maximum power that can be dissipated by the module without exceeding the maximum case temperature versus local ambient temperature (TA) for natural convection through 4 m/s (800 ft./min.). 11 10 9 8 7 6 VI = 75 V VI = 48 V VI = 36 V 5 4 SEE NOTE 3 1 2 3 4 5 6 7 8 9 10 OUTPUT CURRENT, IO (A) 8-2957 (F) Note: Pending improvement will lower the power dissipation. Figure 23. QW050A1 Power Dissipation vs. Output Current at 25 C 16 POWER DISSIPATION, PD (W) Heat Transfer Without Heat Sinks Data Sheet April 2008 14 12 10 8 VI = 75 V VI = 54 V VI = 36 V 6 SEE NOTE 4 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 OUTPUT CURRENT, IO (A) 8-2958 (F) Note: Pending improvement will lower the power dissipation. Figure 24. QW075A1 Power Dissipation vs. Output Current at 25 C 12 Lineage Power Data Sheet April 2008 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Heat Transfer Without Heat Sinks (continued) POWER DISSIPATION, PD (W) 20 4.0 m/s (800 ft./min.) 3.5 m/s (700 ft./min.) 3.0 m/s (600 ft./min.) 2.5 m/s (500 ft./min.) 2.0 m/s (400 ft./min.) 1.5 m/s (300 ft./min.) 1.0 m/s (200 ft./min.) 0.5 m/s (100 ft./min.) 0.1 m/s (20 ft./min.) NATURAL CONVECTION 15 10 CASE-TO-AMBIENT THERMAL RESISTANCE, CA (C/W) Thermal Considerations (continued) 11 10 NO HEAT SINK 1/4 IN. HEAT SINK 1/2 IN. HEAT SINK 1 IN. HEAT SINK 9 8 7 6 5 4 3 2 1 0 NAT CONV 5 0.5 (100) 1.0 (200) 1.5 (300) 2.0 (400) 2.5 (500) 3.0 (600) AIR VELOCITY, m/s (ft./min.) 8-2107 (C) 0 0 10 20 30 40 50 60 70 80 90 100 LOCAL AMBIENT TEMPERATURE, TA (C) Figure 26. Case-to-Ambient Thermal Resistance Curves; Transverse Orientation 8-2306 (C).a Figure 25. Forced Convection Power Derating with No Heat Sink; Either Orientation The power modules have through-threaded, M3 x 0.5 mounting holes, which enable heat sinks or cold plates to attach to the module. The mounting torque must not exceed 0.56 N-m (5 in.-lb.). For a screw attachment from the pin side, the recommended hole size on the customer's PWB around the mounting holes is 0.130 0.005 inches. If a larger hole is used, the mounting torque from the pin side must not exceed 0.25 N-m (2.2 in.-lbs.). Thermal derating with heat sinks is expressed by using the overall thermal resistance of the module. Total module thermal resistance (ca) is defined as the maximum case temperature rise (TC, max) divided by the module power dissipation (PD): CASE-TO-AMBIENT THERMAL RESISTANCE, CA (C/W) Heat Transfer with Heat Sinks 11 10 NO HEAT SINK 1/4 IN. HEAT SINK 1/2 IN. HEAT SINK 1 IN. HEAT SINK 9 8 7 6 5 4 3 2 1 0 NAT CONV 0.5 (100) 1.0 1.5 2.0 (200) (300) (400) AIR VELOCITY, m/s (ft./min.) 2.5 (500) 3.0 (600) 8-2108 (C) Figure 27. Case-to-Ambient Thermal Resistance Curves; Longitudinal Orientation T C, max (TC - TA ) ca = --------------------= -----------------------PD PD The location to measure case temperature (TC) is shown in Figure 22. Case-to-ambient thermal resistance vs. airflow is shown, for various heat sink configurations, heights, and orientations, as shown in Figures 26 and 27. Longitudinal orientation is defined as the long axis of the module that is parallel to the airflow direction, whereas in the transverse orientation, the long axis is perpendicular to the airflow. These curves were obtained by experimental testing of heat sinks, which are offered in the product catalog. Lineage Power 13 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Data Sheet April 2008 POWER DISSIPATION, PD (W) Heat Transfer with Heat Sinks (continued) 20 18 1 IN. HEAT SINK 1/2 IN. HEAT SINK 1/4 IN. HEAT SINK NO HEAT SINK 16 14 12 10 POWER DISSIPATION, PD (W) Thermal Considerations (continued) 8 20 18 16 14 12 10 8 1 IN. HEAT SINK 1/2 IN. HEAT SINK 1/4 IN. HEAT SINK NO HEAT SINK 6 4 2 0 6 0 10 4 20 30 40 50 60 70 80 LOCAL AMBIENT TEMPERATURE, TA (C) 2 8-2382 (C) 0 0 10 20 30 40 50 60 70 80 90 100 LOCAL AMBIENT TEMPERATURE, TA (C) 8-2380 (C) Figure 30. Heat Sink Power Derating Curves; 1.0 m/s (200 lfm); Transverse Orientation POWER DISSIPATION, PD (W) POWER DISSIPATION, PD (W) Figure 28. Heat Sink Power Derating Curves; Natural Convection; Transverse Orientation 20 18 1 IN. HEAT SINK 1/2 IN. HEAT SINK 1/4 IN. HEAT SINK NO HEAT SINK 16 14 12 10 8 20 18 16 14 12 10 8 1 IN. HEAT SINK 1/2 IN. HEAT SINK 1/4 IN. HEAT SINK NO HEAT SINK 6 4 2 0 6 0 4 10 20 30 40 50 60 70 80 90 100 LOCAL AMBIENT TEMPERATURE, TA (C) 2 8-2383 (C) 0 0 10 20 30 40 50 60 70 80 90 100 LOCAL AMBIENT TEMPERATURE, TA (C) 8-2381 (C) Figure 29. Heat Sink Power Derating Curves; Natural Convection; Longitudinal Orientation 14 90 100 Figure 31. Heat Sink Power Derating Curves; 1.0 m/s (200 lfm); Longitudinal Orientation These measured resistances are from heat transfer from the sides and bottom of the module as well as the top side with the attached heat sink; therefore, the case-to-ambient thermal resistances shown are generally lower than the resistance of the heat sink by itself. The module used to collect the data in Figures 26 and 27 had a thermal-conductive dry pad between the case and the heat sink to minimize contact resistance. The use of Figures 26 and 27 are shown in the following example. Lineage Power Data Sheet April 2008 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Thermal Considerations (continued) Custom Heat Sinks Heat Transfer with Heat Sinks (continued) A more detailed model can be used to determine the required thermal resistance of a heat sink to provide necessary cooling. The total module resistance can be separated into a resistance from case-to-sink (cs) and sink-to-ambient (sa) as shown in Figure 32. Example If an 85 C case temperature is desired, what is the minimum airflow necessary? Assume the QW075A1 module is operating at VI = 54 V and an output current of 15 A, maximum ambient air temperature of 40 C, and the heat sink is 1/2 inch. The module is oriented in the transverse direction. PD TC TS cs Solution TA sa 8-1304 (C) Given: VI = 54 V IO = 15 A TA = 40 C TC = 85 C Heat sink = 1/2 inch Determine PD by using Figure 24: PD = 16 W Then solve the following equation: ( TC - TA ) ca = ----------------------PD 85 - 40 ) ca = (----------------------16 ca = 2.8 C/W Use Figure 26 to determine air velocity for the 1/2 inch heat sink. The minimum airflow necessary for the QW075A1 module is 1.2 m/s (240 ft./min.). Note: Pending improvement will lower the power dissipation and reduce the airflow needed. Figure 32. Resistance from Case-to-Sink and Sink-to-Ambient For a managed interface using thermal grease or foils, a value of cs = 0.1 C/W to 0.3 C/W is typical. The solution for heat sink resistance is: (TC - TA) sa = ------------------------ - cs PD This equation assumes that all dissipated power must be shed by the heat sink. Depending on the userdefined application environment, a more accurate model, including heat transfer from the sides and bottom of the module, can be used. This equation provides a conservative estimate for such instances. EMC Considerations For assistance with designing for EMC compliance, please refer to the FLTR100V10 data sheet (DS99-294EPS). Layout Considerations Copper paths must not be routed beneath the power module mounting inserts. For additional layout guidelines, refer to the FLTR100V10 data sheet (DS99-294EPS). Lineage Power 15 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Data Sheet April 2008 Outline Diagram Dimensions are in millimeters and (inches). Tolerances: x.x mm 0.5 mm (x.xx in. 0.02 in.) x.xx mm 0.25 mm (x.xxx in. 0.010 in.) Top View 36.8 (1.45) 57.9 (2.28) Side View 12.7 (0.50) SIDE LABEL* 0.51 (0.020) 4.1 (0.16) MIN, 2 PLACES 4.1 (0.16) MIN, 6 PLACES 3.5 (0.14) MIN 1.57 (0.062) DIA SOLDER-PLATED BRASS, 2 PLACES 1.02 (0.040) DIA SOLDER-PLATED BRASS, 6 PLACES Bottom View RIVETED CASE PIN (OPTIONAL) 1.09 x 0.76 (0.043 x 0.030) 3.6 (0.14) 50.80 (2.000) 5.3 (0.21) 10.9 (0.43) VO(-) VI(-) 15.24 (0.600) 26.16 (1.030) - SENSE TRIM ON/OFF + SENSE 5.3 (0.21) 7.62 (0.300) 15.24 (0.600) VO(+) VI(+) 7.62 (0.300) MOUNTING INSERTS M3 x 0.5 THROUGH, 4 PLACES 3.81 11.43 (0.150) (0.450) 12.7 (0.50) 11.2 (0.44) 47.2 (1.86) 8-1769 (F).b * Side label includes Lineage name, product designation, safety agency markings, input/output voltage and current ratings, and bar code. 16 Lineage Power Data Sheet April 2008 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Recommended Hole Pattern Component-side footprint. Dimensions are in millimeters and (inches). 5.3 (0.21) 7.62 (0.300) 26.16 (1.030) 15.24 (0.600) 47.2 (1.86) VI(+) VO(+) + SENSE TRIM ON/OFF 7.62 (0.300) - SENSE VI(-) VO(-) 3.81 (0.150) 5.3 (0.21) 10.9 (0.43) 3.6 (0.14) 11.2 (0.44) 50.80 (2.000) 12.7 (0.50) 15.24 (0.600) 11.43 (0.450) MOUNTING INSERTS M3 x 0.5 THROUGH, 4 PLACES CASE PIN (OPTIONAL) 8-1769 (F).b Ordering Information Table 4. Device Codes Input Voltage Output Voltage Output Power Remote On/Off Logic Device Code Comcode 48 V 5V 50 W Negative QW050A1 108153669 48 V 5V 75 W Negative QW075A1 107967218 Optional features can be ordered using the suffixes shown in Table 5. The suffixes follow the last letter of the device code and are placed in descending order. For example, the device codes for a QW050A1 module with the following options are shown below: Auto-restart after overcurrent shutdown QW050A41 Table 5. Device Options Option Suffix Auto-restart after overcurrent shutdown 4 Lineage Power 17 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Data Sheet April 2008 Ordering Information (continued) Table 6. Device Accessories Accessory Comcode 1/4 in. transverse kit (heat sink, thermal pad, and screws) 1/4 in. longitudinal kit (heat sink, thermal pad, and screws) 1/2 in. transverse kit (heat sink, thermal pad, and screws) 1/2 in. longitudinal kit (heat sink, thermal pad, and screws) 1 in. transverse kit (heat sink, thermal pad, and screws) 1 in. longitudinal kit (heat sink, thermal pad, and screws) 848060992 848061008 848061016 848061024 848061032 848061040 Dimensions are in millimeters and (inches). 1/4 IN. 2.280 0.015 (57.91 0.38) 1.450 0.015 (36.83 0.38) 1/2 IN. 1/4 IN. 1/2 IN. 1 IN. 1 IN. 1.850 0.005 (47.24 0.13) 1.030 0.005 (26.16 0.13) 8-2473 (F) 8-2472 (F) Figure 33. Longitudinal Heat Sink Figure 34. Transverse Heat Sink 18 Lineage Power Data Sheet April 2008 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Notes Lineage Power 19 QW050A1 and QW075A1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W and 75 W Data Sheet April 2008 A sia-Pacific Head qu art ers T el: +65 6 41 6 4283 World W ide Headq u arters Lin eag e Po wer Co rp oratio n 30 00 Sk yline D riv e, Mes quite, T X 75149, U SA +1-800-526-7819 (Outs id e U .S.A .: +1- 97 2-2 84 -2626) www.line ag ep ower.co m e-m ail: tech sup port1@ lin ea gep ower.co m Eu ro pe, M id dle-East an d Afric a He ad qu arters T el: +49 8 9 6089 286 Ind ia Head qu arters T el: +91 8 0 28411633 Lineage Power reserves the right to make changes to the produc t(s) or information contained herein without notice. No liability is ass umed as a res ult of their use or applic ation. No rights under any patent acc ompany the sale of any s uc h pr oduct(s ) or information. (c) 2008 Lineage Power Corpor ation, (Mesquite, Texas ) All International Rights Res er ved. April 2008 DS00-179EPS (Replaces DS00-178EPS)