Data Sheet May 1998 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Features The FW250H1 and FW300H1 Power Modules use advanced, surface-mount technology and deliver high-quality, compact, dc-dc conversion at an economical price. Applications Redundant and distributed power architectures Options Heat sink available for extended operation Size: 61.0 mm x 116.8 mm x 13.5 mm (2.40 in. x 4.60 in. x 0.53 in.) Wide input voltage range High efficiency: 89% typical Parallel operation with load sharing Output voltage set-point adjustment (trim) Thermal protection Synchronization Power good signal Current monitor Output overvoltage and overcurrent protection Constant frequency Case ground pin Input-to-output isolation Remote sense Remote on/off Short-circuit protection Output overvoltage clamp UL* Recognized, CSA Certified, VDE Licensed CE mark meets 73/23/EEC and 93/68/EEC directives Description The FW250H1 and FW300H1 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 250 W to 300 W at a typical full-load efficiency of 89%. Two or more modules may be paralleled with forced load sharing for redundant or enhanced power applications. The package, which mounts on a printed-circuit board, accommodates a heat sink for high-temperature applications. * UL is a registered trademark of Underwriters Laboratories, Inc. CSA is a registered trademark of Canadian Standards Association. 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.) FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Data Sheet May 1998 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 Input Voltage: Continuous Transient (100 ms) I/O Isolation Voltage Operating Case Temperature (See Thermal Considerations section and Figure 22.) Storage Temperature Symbol Min Max Unit VI VI, trans -- TC -- -- -- -40 80 100 1500 100 Vdc Vdc V C Tstg -55 125 C Electrical Specifications Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature conditions. Table 1. Input Specifications Parameter Operating Input Voltage Maximum Input Current (VI = 0 V to 75 V): FW250H1 FW300H1 Inrush Transient Input Reflected-ripple Current, Peak-to-peak (5 Hz to 20 MHz, 12 H source impedance; see Figure 12.) Input Ripple Rejection (120 Hz) Symbol VI Min 36 Typ 48 Max 75 Unit Vdc II, max II, max i2t -- -- -- -- -- -- 12 12 2.0 A A A2s -- -- 10 -- mAp-p -- -- 60 -- dB 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, dc fuse with a maximum rating of 20 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 Tyco Electronics Corp. FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Data Sheet May 1998 Electrical Specifications (continued) Table 2. Output Specifications Parameter Output Voltage (Over all operating input voltage, resistive load, and temperature conditions until end of life; see Figure 13 and Feature Descriptions.) Output Voltage Set Point (VI = 48 V; IO = IO, max; TC = 25 C) Output Regulation: Line (VI = 36 V to 75 V) Load (IO = IO, min to IO, max) Temperature (TC = -40 C to +100 C) Output Ripple and Noise Voltage (See Figures 7, 8, and 14.): RMS Peak-to-peak (5 Hz to 20 MHz) Output Current (At IO < IO, min, the modules may exceed output ripple specifications.): FW250H1 FW300H1 Output Current-limit Inception (VO = 90% of VO, set; see Feature Descriptions.) Output Short-circuit Current (VO = 1.0 V; indefinite duration, no hiccup mode; see Figures 3 and 4.) External Load Capacitance (electrolytic, total for one unit or multiple paralleled units): FW250H1 FW300H1 Efficiency (VI = 48 V; IO = IO, max; TC = 25 C; see Figures 5, 6, and 13.): FW250H1 FW300H1 Dynamic Response (IO/t = 1 A/10 s, VI = 48 V, TC = 25 C; see Figures 9 and 10.): 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) Symbol VO Min 23.15 Typ -- Max 24.85 Unit Vdc VO, set 23.45 -- 24.55 Vdc -- -- -- -- -- -- 0.01 0.05 100 0.1 0.2 300 % % mV -- -- -- -- -- -- 100 250 mVrms mVp-p IO IO -- -- -- 10.4 12.5 130 A A IO, cli 0.1 0.1 103 % IO, max -- -- -- 150 % IO, max -- -- 330 330 -- -- 5,000 5,000 F F 87 87 89 89 -- -- % % -- -- -- -- 2 200 -- -- %VO, set s -- -- -- -- 2 200 -- -- %VO, set s Min -- 10 Typ 1700 -- Max -- -- Unit pF M Table 3. Isolation Specifications Parameter Isolation Capacitance Isolation Resistance Tyco Electronics Corp. 3 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Data Sheet May 1998 General Specifications Parameter Calculated MTBF (IO = 80% of IO, max; TC = 40 C) Weight Min Typ 1,500,000 -- -- Max 200 (7) Unit hours g (oz.) Feature Specifications Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature conditions. See Feature Descriptions for further 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 15 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 (IO = 80% of IO, max; VO within 1% of steady state) Output Voltage Overshoot Output Voltage Adjustment (See Feature Descriptions.): Output Voltage Remote-sense Range Output Voltage Set-point Adjustment Range (trim) Output Overvoltage Protection (shutdown) Output Current Monitor (IO = IO, max, TC = 70 C) Synchronization: Clock Amplitude Clock Pulse Width Fan-out Capture Frequency Range Overtemperature Shutdown (See Figure 22.) Current Share Accuracy Power Good Signal Interface (See Feature Descriptions.): Low Impedance--Module Operating High Impedance--Module Off 4 Symbol Min Typ Max Unit Von/off Ion/off 0 -- -- -- 1.2 1.0 V mA Von/off Ion/off -- -- -- -- -- -- 30 15 50 50 V A ms -- -- 0 5 %VO, set -- -- -- -- 60 29.5 -- -- -- -- 0.25 0.5 110 34.0 -- V %VO, nom V V/A TC -- 4.00 0.4 -- 425 -- -- -- -- -- -- 105 10 5.00 -- 1 575 -- -- V s -- kHz C %IO, rated Rpwr/good Ipwr/good Rpwr/good Vpwr/good -- -- 1 -- -- -- -- -- 100 1 -- 40 mA M V IO, mon -- -- -- -- Tyco Electronics Corp. FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Data Sheet May 1998 Characteristic Curves The following figures provide typical characteristics for the FW250H1 and FW300H1 power modules. TURN-OFF 9 TURN-ON OUTPUT VOLTAGE, V O (V) 10 INPUT CURRENT, I I (A) 8 7 IO = 10.4 A 6 5 4 IO = 5.2 A 3 2 IO = 1.0 A 1 0 0 5 26 24 22 20 18 16 14 12 10 8 6 4 2 0 VI = 75 V VI = 55 V VI = 36 V 0 10 15 20 25 30 35 40 45 50 55 60 65 70 75 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 OUTPUT CURRENT, IO (A) INPUT VOLTAGE, VI (V) 8-1698 (C) Figure 1. Typical FW250H1 Input Characteristics at Room Temperature 8-1700 (C) Figure 3. Typical FW250H1 Output Characteristics at Room Temperature 12 25 OUTPUT VOLTAGE, VO (V) INPUT CURRENT, II (A) 10 IO = 12.5 A 8 6 IO = 6.25 A 4 2 IO = 1.25 A 0 0 10 20 30 40 50 60 70 80 INPUT VOLTAGE, VI (V) 15 10 VI = 75 V VI = 55 V VI = 36 V 5 0 0 2 4 6 8 10 12 14 16 18 OUTPUT CURRENT, IO (A) 8-1699 (C) Figure 2. Typical FW300H1 Input Characteristics at Room Temperature Tyco Electronics Corp. 20 8-1701 (C) Figure 4. Typical FW300H1 Output Characteristics at Room Temperature 5 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Data Sheet May 1998 Characteristic Curves (continued) 90 OUTPUT VOLTAGE, VO (V) (10 mV/div) 89 EFFICIENCY, (%) 88 87 86 85 VI = 75 V VI = 55 V VI = 36 V 84 83 82 VI = 48 V 81 80 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 OUTPUT CURRENT, IO (A) 8-1702 (C) Figure 5. Typical FW250H1 Efficiency vs. Output Current at Room Temperature TIME, t (500 ns/div) 8-1704 (C) Figure 7. Typical FW250H1 Output Ripple Voltage at Room Temperature and 50 A Output 90 89 87 86 VI = 75 V VI = 55 V VI = 36 V 85 84 83 82 81 80 0 2 4 6 8 10 12 OUTPUT CURRENT, IO (A) OUTPUT VOLTAGE, VO (V) (10 mV/div) EFFICIENCY, (%) 88 VI = 48 V 8-1703 (C) Figure 6. Typical FW300H1 Efficiency vs. Output Current at Room Temperature TIME, t (500 ns/div) 8-1705 (C) Figure 8. Typical FW300H1 Output Ripple Voltage at Room Temperature and 60 A Output 6 Tyco Electronics Corp. Data Sheet May 1998 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W REMOTE ON/OFF, V ON/OFF (V) 24 OUTPUT VOLTAGE, VO (V) (5 V/div) OUTPUT CURRENT, IO (A) (2 A/div) OUTPUT VOLTAGE, VO (V) (200 mV/div) Characteristic Curves (continued) 5.2 2.6 TIME, t (50 s/div) 8-1706 (C) OUTPUT CURRENT, IO (A) (2 A/div) OUTPUT VOLTAGE, VO (V) (200 mV/div) Figure 9. Typical FW250H1 Transient Response to Step Decrease in Load from 50% to 25% of Full Load at Room Temperature and 48 V Input (Waveform Averaged to Eliminate Ripple Component.) 0 24 0 TIME, t (10 ms/div) 8-1709 (C) Figure 11. Typical FW250H1 Start-Up Transient at Room Temperature, 48 V Input, and Full Load 24 8 5.2 TIME, t (50 s/div) 8-1707 (C) Figure 10. Typical FW250H1 Transient Response to Step Increase in Load from 50% to 75% of Full Load at Room Temperature and 48 V Input (Waveform Averaged to Eliminate Ripple Component.) Tyco Electronics Corp. 7 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Test Configurations Data Sheet May 1998 Design Considerations Input Source Impedance TO OSCILLOSCOPE LTEST VI(+) 12 H Cs 220 F ESR < 0.1 @ 20 C, 100 kHz BATTERY 100 F ESR < 0.3 @ 100 kHz VI(-) 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 12, a 100 F electrolytic capacitor (ESR < 0.3 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. 8-203 (C).o 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 12. Input Reflected-Ripple Test Setup SENSE(+) VI(+) VO(+) VI(-) VO(-) IO II CONTACT RESISTANCE 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., UL-1950, CSA 22.2-950, and EN60950. For the converter output to be considered meeting the requirements of safety extra-low voltage (SELV), one of the following must be true: SENSE(-) SUPPLY Safety Considerations LOAD CONTACT AND DISTRIBUTION LOSSES 8-683 (C).f 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. [VO(+) - VO(-)]IO = -------------------------------------------------- x 100 [VI(+) - VI(-)]II All inputs are SELV and floating, with the output also floating. All inputs are SELV and grounded, with the output also grounded. Any non-SELV input must be provided with reinforced insulation from any other hazardous voltages, including the ac mains, and must have a SELV reliability test performed on it in combination with the converters. Inputs must meet SELV requirements. If the input meets extra-low voltage (ELV) requirements, then the converter's output is considered ELV. Figure 13. Output Voltage and Efficiency Measurement Test Setup The input to these units is to be provided with a maximum 20 A normal-blow fuse in the ungrounded lead. COPPER STRIP V O (+) Electrical Descriptions 1.0 F 330 F SCOPE RESISTIVE LOAD V O (-) 8-513 (C).n Note: Use a 0.1 F ceramic capacitor and a 330 F aluminum or tantalum capacitor. The 330 F capacitor is needed for stability, Scope measurement should be made using a BNC socket. Position the load between 50 mm and 76 mm (2 in. and 3 in.) from the module. Figure 14. Peak-to-Peak Output Noise Measurement Test Setup 8 Current Limit To provide protection in a fault (output overload) condition, the unit is equipped with internal current-limiting circuitry and can endure current limiting for an unlimited duration. 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 current-limit circuit can exhibit either foldback or tailout characteristics (output-current decrease or increase). The unit operates normally once the output current is brought back into its specified range. Tyco Electronics Corp. Data Sheet May 1998 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Feature Descriptions Remote On/Off SENSE(+) SENSE(-) 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 15). A logic low is Von/off = 0 V to 1.2 V, during which the module is on. The maximum Ion/off during a logic low is 1 mA. The switch should maintain a logic-low 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. SENSE(-) VO(+) ON/OFF + Von/off - VO(+) VI(-) VO(-) IO CONTACT RESISTANCE LOAD CONTACT AND DISTRIBUTION LOSSES 8-651 (C).e Figure 16. Effective Circuit Configuration for Single-Module Remote-Sense Operation 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. With an external resistor between the TRIM and SENSE(-) pins (Radj-down), the output voltage set point (VO, adj) decreases (see Figure 17). The following equation determines the required external-resistor value to obtain a percentage output voltage change of %. SENSE(+) Ion/off VI(+) II Output Voltage Set-Point Adjustment (Trim) If not using the remote on/off feature, short the ON/OFF pin to VI(-). CASE SUPPLY VI(+) VO(-) VI(-) 8-580 (C).d Figure 15. 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 value indicated in the output overvoltage shutdown section of the Feature Specifications table. This limit includes any increase in voltage due to remote-sense compensation and output voltage set-point adjustment (trim), see Figure 16. If not using the remote-sense feature to regulate the output at the point of load, connect SENSE(+) to VO(+) and SENSE(-) to VO(-) at the module. 205 R adj-down = ---------- - 2.255 % k The test results for this configuration are displayed in Figure 18. 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 19). The following equation determines the required external-resistor value to obtain a percentage output voltage change of %. % ( V O, nom ( 1 + ---------- ) - 1.225 ) 100 R adj-up = ------------------------------------------------------------------------- 205 - 2.255 k ( 1.225% ) The test results for this configuration are displayed in Figure 20. The voltage between the VO(+) and VO(-) terminals must not exceed the minimum value of the output overvoltage protection as indicated in the Feature Specifications table. This limit includes any increase in voltage due to remote-sense compensation and output voltage set-point adjustment (trim). See Figure 16. If not using the trim feature, leave the TRIM pin open. Tyco Electronics Corp. 9 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Data Sheet May 1998 Output Voltage Set-Point Adjustment (Trim) (continued) VI(+) VO(+) ON/OFF CASE SENSE(+) RLOAD TRIM Radj-down VI(-) SENSE(-) ADJUSTMENT RESISTOR VALUE () Feature Descriptions (continued) 100k 10k 1k 100 0 VO(-) 2 4 6 8 10 PERCENT CHANGE IN OUTPUT VOLTAGE (%) 8-1934 (C) 8-748 (C).b Figure 20. Resistor Selection for Increased Output Voltage Figure 17. Circuit Configuration to Decrease Output Voltage ADJUSTMENT RESISTOR VALUE () Output Overvoltage Protection 1M The output voltage is monitored at the VO(+) and VO(-) pins of the module. If the voltage at these pins exceeds the value indicated in the Feature Specifications table, the module will shut down and latch off. Recovery from latched shutdown is accomplished by cycling the dc input power off for at least 1.0 s or toggling the primary referenced on/off signal for at least 1.0 s. 100k 10k Output Current Monitor 1k 0 10 20 30 40 PERCENT CHANGE IN OUTPUT VOLTAGE (%) 8-1171 (C).g Figure 18. Resistor Selection for Decreased Output Voltage VI(+) ON/OFF VO(+) SENSE(+) Radj-up CASE VI(-) TRIM RLOAD SENSE(-) The CURRENT MON pin provides a dc voltage proportional to the dc output current of the module given in the Feature Specifications table. For example, on the FW250H1, the V/A ratio is set at 250 mV/A 10% @ 70 C case. At a full load current of 12.5 A, the voltage on the CURRENT MON pin is 3.13 V. The current monitor signal is referenced to the SENSE(-) pin on the secondary and is supplied from a source impedance of approximately 2 k. It is recommended that the CURRENT MON pin be left open when not in use, although no damage will result if the CURRENT MON pin is shorted to secondary ground. Directly driving the CURRENT MON pin with an external source will detrimentally affect operation of the module and should be avoided. VO(-) 8-715 (C).b Figure 19. Circuit Configuration to Increase Output Voltage 10 Tyco Electronics Corp. Data Sheet May 1998 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Feature Descriptions (continued) Overtemperature Shutdown Synchronization To provide protection in a fault condition, the unit is equipped with an overtemperature shutdown circuit. The shutdown circuit will not engage unless the unit is operated above the maximum case temperature. Recovery from overtemperature shutdown is accomplished by cycling the dc input power off for at least 1.0 s or toggling the primary referenced on/off signal for at least 1.0 s. Any module can be synchronized to any other module or to an external clock using the SYNC IN or SYNC OUT pins. The modules are not designed to operate in a master/slave configuration; that is, if one module fails, the other modules will continue to operate. SYNC IN Pin This pin can be connected either to an external clock or directly to the SYNC OUT pin of another FW250x or FW300x module. If an external clock signal is applied to the SYNC IN pin, the signal must be a 500 kHz (50 kHz) square wave with a 4 Vp-p amplitude. Operation outside this frequency band will detrimentally affect the performance of the module and must be avoided. If the SYNC IN pin is connected to the SYNC OUT pin of another module, the connection should be as direct as possible, and the VI(-) pins of the modules must be shorted together. Unused SYNC IN pins should be tied to VI(-). If the SYNC IN pin is unused, the module will operate from its own internal clock. Forced Load Sharing (Parallel Operation) For either redundant operation or additional power requirements, the power modules can be configured for parallel operation with forced load sharing (see Figure 21). For a typical redundant configuration, Schottky diodes or an equivalent should be used to protect against short-circuit conditions. Because of the remote sense, the forward-voltage drops across the Schottky diodes do not affect the set point of the voltage applied to the load. For additional power requirements, where multiple units are used to develop combined power in excess of the rated maximum, the Schottky diodes are not needed. Good layout techniques should be observed for noise immunity. To implement forced load sharing, the following connections must be made: SYNC OUT Pin This pin contains a clock signal referenced to the VI(-) pin. The frequency of this signal will equal either the module's internal clock frequency or the frequency established by an external clock applied to the SYNC IN pin. The parallel pins of all units must be connected together. The paths of these connections should be as direct as possible. All remote-sense pins should be connected to the power bus at the same point, i.e., connect all SENSE(+) pins to the (+) side of the power bus at the same point and all SENSE(-) pins to the (-) side of the power bus at the same point. Close proximity and directness are necessary for good noise immunity. When synchronizing several modules together, the modules can be connected in a daisy-chain fashion where the SYNC OUT pin of one module is connected to the SYNC IN pin of another module. Each module in the chain will synchronize to the frequency of the first module in the chain. When not using the parallel feature, leave the PARALLEL pin open. To avoid loading effects, ensure that the SYNC OUT pin of any one module is connected to the SYNC IN pin of only one module. Any number of modules can be synchronized in this daisy-chain fashion. Tyco Electronics Corp. 11 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Data Sheet May 1998 Feature Descriptions (continued) Thermal Considerations Forced Load Sharing (Parallel Operation) Introduction (continued) 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 occurs at the position indicated in Figure 22. PARALLEL SENSE(+) SENSE(-) CASE VO(+) ON/OFF VI(+) VO(-) VI(-) PARALLEL SENSE(+) SENSE(-) CASE VI(+) MEASURE CASE TEMPERATURE HERE VO(+) VI(-) ON/OFF SYNC IN VO(+) 30.5 (1.20) ON/OFF VI(+) VO(-) VI(-) VO(-) SYNC OUT CASE 8-581 (C) Figure 21. Wiring Configuration for Redundant Parallel Operation Power Good Signal The PWR GOOD pin provides an open-drain signal (referenced to the SENSE(-) pin) that indicates the operating state of the module. A low impedance (<100 ) between PWR GOOD and SENSE(-) indicates that the module is operating. A high impedance (>1 M) between PWR GOOD and SENSE(-) indicates that the module is off or has failed. The PWR GOOD pin can be pulled up through a resistor to an external voltage to facilitate sensing. This external voltage level must not exceed 40 V, and the current into the PWR GOOD pin during the low-impedance state should be limited to 1 mA maximum. 12 82.6 (3.25) 8-1303 (C).a Note: Top view, measurements shown in millimeters and (inches). Pin locations are for reference only. Figure 22. Case Temperature Measurement Location The temperature at this location should not exceed 100 C. The maximum case temperature can be limited to a lower value for extremely high reliability. The output power of the module should not exceed the rated power for the module as listed in the Ordering Information table. For additional information about these modules, refer to the Thermal Management for FC- and FW-Series 250 W--300 W Board-Mounted Power Modules Technical Note (TN96-009EPS). Tyco Electronics Corp. Data Sheet May 1998 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Thermal Considerations (continued) Heat Transfer with Heat Sinks Heat Transfer Without Heat Sinks The power modules have through-threaded, M3 x 0.5 mounting holes, which enable heat sinks or cold plates to be attached to the module. The mounting torque must not exceed 0.56 N-m (5 in.-lb.). For the 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.). Derating curves for forced-air cooling without a heat sink are shown in Figures 23 and 24. These curves can be used to determine the appropriate airflow for a given set of operating conditions. For example, if the unit with airflow along its length dissipates 20 W of heat, the correct airflow in a 40 C environment is 1.0 m/s (200 ft./min.). POWER DISSIPATION, PD (W) 70 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.) 60 50 40 30 20 10 0.1 m/s (20 ft./min.) NAT. CONV. 0 0 10 20 30 40 50 60 70 80 90 100 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): (TC - TA) C, max ca = T = ------------------------------------------PD PD The location to measure case temperature (TC) is shown in Figure 22. Case-to-ambient thermal resistance vs. airflow for various heat sink configurations is shown in Figure 25 and Figure 26. These curves were obtained by experimental testing of heat sinks, which are offered in the product catalog. LOCAL AMBIENT TEMPERATURE, TA (C) 4.5 Figure 23. Convection Power Derating with No Heat Sink; Airflow Along Width (Transverse) POWER DISSIPATION, PD (W) 70 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.) 60 50 40 30 CASE-TO-AMBIENT THERMAL RESISTANCE, RCA (C/W) 8-1315 (C) 1 1/2 in. HEAT SINK 1 in. HEAT SINK 1/2 in. HEAT SINK 1/4 in. HEAT SINK NO HEAT SINK 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0 0.5 (100) 1.0 (200) 1.5 (300) 2.0 (400) 2.5 (500) 3.0 (600) AIR VELOCITY, m/s (ft./min.) 8-1321 (C) 20 10 Figure 25. Case-to-Ambient Thermal Resistance Curves; Transverse Orientation 0.1 m/s (20 ft./min.) NAT. CONV. 0 0 10 20 30 40 50 60 70 80 90 100 LOCAL AMBIENT TEMPERATURE, TA (C) 8-1314 (C) Figure 24. Convection Power Derating with No Heat Sink; Airflow Along Length (Longitudinal) Tyco Electronics Corp. 13 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Thermal Considerations (continued) CASE-TO-AMBIENT THERMAL RESISTANCE, RCA (C/W) 4.5 1 1/2 in. HEAT SINK 1 in. HEAT SINK 1/2 in. HEAT SINK 1/4 in. HEAT SINK NO HEAT SINK 3.5 3.0 2.5 POWER DISSIPATION, PD (W) 35 Heat Transfer with Heat Sinks (continued) 4.0 Data Sheet May 1998 2.0 30 VI = 75 V VI = 55 V VI = 36 V 25 20 15 10 5 0 0.0 1.0 1.5 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 OUTPUT CURRENT, IO (A) 1.0 8-1711 (C) 0.5 0.0 0 0.5 (100) 1.0 (200) 1.5 (300) 2.0 (400) 2.5 (500) 3.0 (600) Figure 27. FW250H1 Power Dissipation vs. Output Current AIR VELOCITY, m/s (ft./min.) 8-1320 (C) 50 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 25 and 26 had a thermal-conductive dry pad between the case and the heat sink to minimize contact resistance. To choose a heat sink, determine the power dissipated as heat by the unit for the particular application. Figures 27 and 28 show typical heat dissipation for a range of output currents and three voltages for the FW250H1 and FW300H1. 14 45 POWER DISSIPATION, P D (W) Figure 26. Case-to-Ambient Thermal Resistance Curves; Longitudinal Orientation 40 35 VI = 75 V VI = 55 V VI = 36 V 30 25 20 15 10 5 0 0 2 4 6 8 10 12 OUTPUT CURRENT, IO (A) 8-1712 (C) Figure 28. FW300H1 Power Dissipation vs. Output Current Tyco Electronics Corp. Data Sheet May 1998 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 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 29. Example If an 85 C case temperature is desired, what is the minimum airflow necessary? Assume the FW250H1 module is operating at nominal line and an output current of 10 A, maximum ambient air temperature of 40 C, and the heat sink is 0.5 inch. PD TC TS cs Solution Given: VI = 54 V IO = 10 A TA = 40 C TC = 85 C Heat sink = 0.5 inch. Determine PD by using Figure 27: PD = 28 W Then solve the following equation: TC - TA) ca = (----------------------PD 85 - 40 ) ca = (----------------------28 - ca = 1.61 C/W Use Figures 25 and 26 to determine air velocity for the 0.5 inch heat sink. The minimum airflow necessary for the FW250H1 module depends on heat sink fin orientation and is shown below: 1.25 m/s (250 ft./min.) (oriented along width) 1.5 m/s (300 ft./min.) (oriented along length) Tyco Electronics Corp. TA sa 8-1304 (C) Figure 29. Resistance from Case-to-Sink and Sinkto-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. Layout Considerations Copper paths must not be routed beneath the power module mounting inserts. 15 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Data Sheet May 1998 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 116.8 (4.60) 61.0 (2.40) Side View SIDE LABEL* 13.5 (0.53) 1.57 0.05 (0.062 0.002) DIA SOLDER-PLATED BRASS, 11 PLCS (VOUT-, VOUT+, VIN-, VIN+) 5.1 (0.20) MIN 1.02 0.05 (0.040 0.002) DIA SOLDER-PLATED BRASS 9 PLCS Bottom View MOUNTING INSERTS M3 x 0.5 THROUGH 4 PLCS 66.04 (2.600) 2.54 (0.100) TYP 12.7 (0.50) 7.62 (0.300) 30.48 (1.200) 50.8 (2.00) CASE SYNC OUT SYNC IN ON/OFF 2.54 (0.100) TYP SENSE- SENSE+ TRIM PARALLEL CURRENT MON PWR GOOD 12.70 17.78 (0.500) (0.700) 22.86 (0.900) 5.1 (0.20) VO- VI- VO+ 10.16 (0.400) 15.24 (0.600) 30.48 5.08 20.32 (1.200) (0.200) (0.800) 25.40 (1.000) 35.56 (1.400) VI+ 5.1 (0.20) 106.68 (4.200) 8-1650 (C) * Side label includes Tyco name, product designation, safety agency markings, input/output voltage and current ratings, and bar code. 16 Tyco Electronics Corp. Data Sheet May 1998 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Recommended Hole Pattern Component-side footprint. Dimensions are in millimeters and (inches). MOUNTING INSERTS 66.04 (2.600) 2.54 (0.100) TYP 7.62 (0.300) 5.1 (0.20) 7.62 12.7 (0.300) (0.50) 30.48 (1.200) 20.32 (0.800) 10.16 (0.400) 5.08 (0.200) VO- 25.40 35.56 (1.000) (1.400) PWR GOOD CURRENT MON PARALLEL TRIM SENSE+ SENSE- 15.24 (0.600) 2.54 (0.100) TYP 7.62 (0.300) CASE SYNC OUT SYNC IN ON/OFF VI- VO+ VI+ 12.70 (0.500) 17.78 (0.700) 22.86 (0.900) 30.48 (1.200) 50.8 (2.00) 5.1 (0.20) 106.68 (4.200) 8-1650 (C) Ordering Information Input Voltage 48 V 48 V Tyco Electronics Corp. Output Voltage 24 V 24 V Output Power 250 W 300 W Device Code FW250H1 FW300H1 Comcode 108026840 107430324 17 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Data Sheet May 1998 Notes 18 Tyco Electronics Corp. Data Sheet May 1998 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Notes Tyco Electronics Corp. 19 FW250H1 and FW300H1 Power Modules: dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 250 W to 300 W Data Sheet March 27, 2001 Tyco Electronics Power Systems, Inc. 3000 Skyline Drive, Mesquite, TX 75149, USA +1-800-526-7819 FAX: +1-888-315-5182 (Outside U.S.A.: +1-972-284-2626, FAX: +1-972-284-2900 http://power.tycoeleectronics.com Tyco Electronics Corportation reserves the right to make changes to the product(s) or information contained herein without notice. No liability is assumed as a result of their use or application. No rights under any patent accompany the sale of any such product(s) or information. (c) 2001 Tyco Electronics Corporation, Harrisburg, PA. All International Rights Reserved. Printed in U.S.A. May 1998 DS97-516EPS Printed on Recycled Paper