Data Sheet May 1999 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Features The FC250R Power Module uses advanced, surface-mount technology and delivers high-quality, compact, dc-dc conversion at an economical price. Applications ■ 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: 88% typical ■ Parallel operation with load sharing ■ Adjustable output voltage ■ Thermal protection ■ Synchronization ■ Power good signal ■ Current monitor ■ Output overvoltage and overcurrent protection ■ Constant frequency ■ Redundant and/or distributed power architectures ■ Case ground pin ■ Workstations ■ Input-to-output isolation ■ EDP equipment ■ Remote sense ■ Telecommunication ■ Remote on/off ■ Short-circuit protection ■ Output overvoltage clamp ISO9001 Certified manufacturing facilities Options ■ Heat sinks available for extended operation ■ ■ Choice of primary remote on/off logic configurations ■ UL* 1950 Recognized, CSA † C22.2 No. 950-95 Certified, and VDE 0805 (EN60950, IEC950) Licensed Description The FC250R Power Module is a dc-dc converter that operates over an input voltage range of 18 Vdc to 36 Vdc and provides a precisely regulated dc output. The outputs are fully isolated from the inputs, allowing versatile polarity configurations and grounding connections. The module has a maximum power rating of 250 W at a typical full-load efficiency of 88%. 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. FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Data Sheet May 1999 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 I/O Isolation Voltage Operating Case Temperature (See Thermal Considerations section and Figure 18.) Storage Temperature Symbol VI — TC Min — — –40 Max 50 1500 100 Unit 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 36 V) Inrush Transient Input Reflected-ripple Current, Peak-to-peak (5 Hz to 20 MHz, 12 µH source impedance; see Figure 8.) Input Ripple Rejection (120 Hz) Symbol VI II, max i2t Min 18 — — Typ 28 — — Max 36 22 4.0 Unit Vdc 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 fuse with a maximum rating of 25 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. FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Data Sheet May 1999 Electrical Specifications (continued) Table 2. Output Specifications Parameter Output Voltage Set Point (VI = 28 V; IO = IO, max; TC = 25 °C) Output Voltage (Over all operating input voltage, resistive load, and temperature conditions until end of life; see Figure 9 and Feature Descriptions.) Output Regulation: Line (VI = 18 V to 36 V) Load (IO = IO, min to IO, max) Temperature (TC = –40 °C to +100 °C) Output Ripple and Noise Voltage (See Figures 4 and 10.): RMS Peak-to-peak (5 Hz to 20 MHz) Output Current (At IO < IO, min, the modules may exceed output ripple specifications.) 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 Figure 2.) External Load Capacitance (total for one unit or multiple paralleled units) Efficiency (VI = 28 V; IO = IO, max; TC = 25 °C; see Figures 3 and 9.) Switching Frequency Dynamic Response (∆IO/∆t = 1 A/10 µs, VI = 28 V, TC = 25 °C (tested with a 330 µF aluminum and a 1.0 µF ceramic capacitor across the load); see Figures 5 and 6.): 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, set Min 27.45 Typ 28.0 Max 28.55 Unit Vdc VO 27.16 — 28.84 Vdc — — — — — — 0.01 0.05 100 0.1 0.2 300 % % mV — — IO — — 0.3 — — — 50 100 9.0 mVrms mVp-p A IO, cli 103* — 130* % IO, max — — — 150 % IO, max — 330 — † µF η — 88 — % — — 500 — kHz — — — — 300 250 — — mV µs — — — — 400 250 — — mV µs Min — 10 Typ 1700 — Max — — Unit pF MΩ * These are manufacturing test limits. In some situations, results may differ. † Please consult your sales representative or the factory. Table 3. Isolation Specifications Parameter Isolation Capacitance Isolation Resistance Tyco Electronics Corp. 3 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Data Sheet May 1999 General Specifications Parameter Calculated MTBF (IO = 80% of IO, max; TC = 40 °C) Weight Min Typ 1,800,000 — — 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 36 V; open collector or equivalent compatible; signal referenced to VI (–) terminal; see Figure 11 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 µA 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.): Note: Do not allow the combination of remote-sense and trim to exceed 28.5 V on the output. 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 18.) Current Share Accuracy Power Good Signal Interface (See Feature Descriptions.): Low Impedance—Module Operating High Impedance—Module Off Symbol Min Typ Max Unit Von/off Ion/off 0 — — — 1.2 1.0 V mA Von/off Ion/off — — — — — — 50 15 50 100 V µA ms — — 0 5 %VO, set — — — — 60 30.9 0.34* — — — 0.40 0.5 102 37.0 0.45* V %VO, nom V V/A TC — 4.00 0.4 — 450 — — — — — — 105 10 5.00 — 1 550 — — V µs — kHz °C %IO, rated Rpwr/good Ipwr/good Rpwr/good Vpwr/good — — 1 — — — — — 100 1 — 40 Ω mA MΩ V IO, mon — — — — * These are manufacturing test limits. In some situations, results may differ. 4 Tyco Electronics Corp. FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Data Sheet May 1999 Characteristic Curves The following figures provide typical characteristics for the power module. 18 88 87 IO = 8.93 A (%) 14 12 10 EFFICIENCY, INPUT CURRENT, II (A) 16 IO = 4.47 A 8 6 4 86 85 84 VI = 18 V 83 VI = 24 V VI = 36 V 82 IO = 0.89 A 2 81 0 0 5 10 15 20 25 30 35 80 40 0 1 2 3 4 5 6 7 8 INPUT VOLTAGE, VI (V) OUTPUT CURRENT, IO (A) 8-2175 (C) 8-1667 (C) Figure 1. Typical FC250R Input Characteristics at Room Temperature, IO = Full Load Figure 3. Typical FC250R Efficiency vs. Output Current at Room Temperature VI = 18 V 25 20 VI = 18 V 15 VI = 28 V VI = 36 V 10 5 0 0 2 4 6 8 10 12 14 OUTPUT VOLTAGE, VO (V) (50 mV/div) OUPUT VOLTAGE, VO (V) 30 VI = 24 V VI = 36 V OUTPUT CURRENT, IO (A) 8-2176 (C) Figure 2. Typical FC250R Output Characteristics at Room Temperature TIME, t (500 ns/div) 8-1668 (C) Figure 4. Typical FC250R Output Ripple Voltage at Room Temperature and 9 A Output Tyco Electronics Corp. 5 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Data Sheet May 1999 REMOTE ON/OFF VOLTAGE, VON/OFF (V) OUTPUT VOLTAGE, VO (V) (10 V/div) OUTPUT CURRENT, IO (A) (1 A/div) OUTPUT VOLTAGE, VO (V) (200 mV/div) Characteristic Curves (continued) 28.0 28 V 4.50 0V 2.25 TIME, t (20 ms/div) 8-2177 (C) TIME, t (50 µs/div) 8-1669 (C) Note: Tested with a 330 µF aluminum and a 1.0 µF ceramic capacitor across the load. OUTPUT CURRENT, IO (A) (1 A/div) OUTPUT VOLTAGE, VO (V) (200 mV/div) Figure 5. Typical FC250R Transient Response to Step Decrease in Load from 50% to 25% of Full Load at Room Temperature and 28 V Input (Waveform Averaged to Eliminate Ripple Component.) Note: Tested with a 330 µF aluminum and a 1.0 µF ceramic capacitor across the load. Figure 7. Typical FC250R Start-Up Transient at Room Temperature, 28 V Input, and Full Load 28.0 6.75 4.50 TIME, t (50 µs/div) 8-1670 (C) Note: Tested with a 330 µF aluminum and a 1.0 µF ceramic capacitor across the load. Figure 6. Typical FC250R Transient Response to Step Increase in Load from 50% to 75% of Full Load at Room Temperature and 28 V Input (Waveform Averaged to Eliminate Ripple Component.) 6 Tyco Electronics Corp. FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Data Sheet May 1999 Test Configurations Design Considerations Input Source Impedance TO OSCILLOSCOPE LTEST VI(+) 12 µH Cs 220 µF ESR < 0.1 Ω @ 20 °C, 100 kHz BATTERY 100 µF ESR < 0.3 Ω @ 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 8, a 100 µF electrolytic capacitor (ESR < 0.3 Ω 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 µH. Capacitor CS offsets possible battery impedance. Measure current as shown above. Figure 8. Input Reflected-Ripple Test Setup SENSE(+) 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). SENSE(–) VI(+) SUPPLY VO(+) IO II VI(–) LOAD VO(–) CONTACT RESISTANCE CONTACT AND DISTRIBUTION LOSSES For the converter output to be considered meeting the requirements of safety extra-low voltage (SELV), the input must meet SELV requirements. The power module has extra-low voltage (ELV) outputs when all inputs are ELV. 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 η = -------------------------------------------------- x 100 [VI(+) – VI(–)]II Feature Descriptions % Overcurrent Protection Figure 9. Output Voltage and Efficiency Measurement Test Setup COPPER STRIP V O (+) 1.0 µF 330 µF SCOPE The input to these units is to be provided with a maximum 25 A normal-blow fuse in the ungrounded lead. RESISTIVE LOAD V O (–) 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. 8-513 (C).n Note: Use a 0.1 µF ceramic capacitor and a 330 µF aluminum or tantalum capacitor. The 330 µF 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 10. Peak-to-Peak Output Noise Measurement Test Setup Tyco Electronics Corp. 7 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Data Sheet May 1999 Feature Descriptions (continued) 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 11). 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 µA. SENSE(–) VO(+) ON/OFF + Von/off – VI(–) VO(–) IO II CONTACT RESISTANCE LOAD CONTACT AND DISTRIBUTION LOSSES 8-651 (C).e Figure 12. Effective Circuit Configuration for Single-Module Remote-Sense Operation If not using the trim feature, leave the TRIM pin open. VI(+) VO(–) VI(–) 8-580 (C).d Figure 11. 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 12. 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. 8 VO(+) 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. SENSE(+) Ion/off VI(+) Output Voltage Set-Point Adjustment (Trim) If not using the remote on/off feature, short the ON/OFF pin to VI(–). CASE SUPPLY With an external resistor between the TRIM and SENSE(–) pins (Radj-down), the output voltage set point (VO, adj) decreases (see Figure 13). The following equation determines the required external-resistor value to obtain a percentage output voltage change of ∆%. 205 R adj-down = ---------- – 2.255 k Ω ∆% The test results for this configuration are displayed in Figure 14. 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 15). Note: The output voltage of this module may be increased to a maximum of 0.5 V. The 0.5 V is the combination of both the remote sense and the output voltage set-point adjustment (trim). Do not exceed 28.5 V between the VO(+) and VO(–) terminals. The following equation determines the required external-resistor value to obtain a percentage output voltage change of ∆%. V O ( 100 + ∆% ) ( 100 + 2∆% ) Radj-up = --------------------------------------- – ---------------------------------- kΩ 1.225∆% ∆% Only trim up to 0.5 V maximum; see note above. Tyco Electronics Corp. Data Sheet May 1999 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Feature Descriptions (continued) VI(+) Output Voltage Set-Point Adjustment (Trim) (continued) ON/OFF The test results for this configuration are displayed in Figure 15. CASE 8-715 (C).b SENSE(+) Figure 15. Circuit Configuration to Increase Output Voltage RLOAD TRIM SENSE(–) 8-748 (C).b Figure 13. Circuit Configuration to Decrease Output Voltage 10k 1k ADJUSTMENT RESISTOR VALUE (Ω) VO(–) ADJUSTMENT RESISTOR VALUE (Ω) SENSE(–) VO(–) Radj-down VI(–) RLOAD TRIM VO(+) ON/OFF CASE SENSE(+) Radj-up VI(–) VI(+) VO(+) 100M 10M 1M 0.0 100 0.4 0.8 1.2 1.6 2.0 % CHANGE IN OUTPUT VOLTAGE (∆%) 8-2178 (C) Figure 16. Resistor Selection for Increased Output Voltage 10 1 0 10 20 30 40 Output Overvoltage Protection PERCENT CHANGE IN OUTPUT VOLTAGE (∆%) 8-1933 (C) Figure 14. Resistor Selection for Decreased Output Voltage Tyco Electronics Corp. 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. 9 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Data Sheet May 1999 Feature Descriptions (continued) SYNC OUT Pin Output Current Monitor 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 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 FC250R, the V/A ratio is set at 370 mV/A ± 10% @ 70 °C case. At a full load current of 9.0 A, the voltage on the CURRENT MON pin is 3.33 V. The current monitor signal is referenced to the SENSE(–) pin on the secondary and is supplied from a source impedance of approximately 2 kΩ. 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. Synchronization 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. 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. 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. Overtemperature Protection To provide protection in a fault condition, the unit is equipped with an overtemperature shutdown circuit. The shut down 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. SYNC IN Pin This pin can be connected either to an external clock or directly to the SYNC OUT pin of another FC250x 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. 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 17). 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. 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. 10 Tyco Electronics Corp. Data Sheet May 1999 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Feature Descriptions (continued) Forced Load Sharing (Parallel Operation) (continued) Good layout techniques should be observed for noise immunity. To implement forced load sharing, the following connections must be made: ■ ■ 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 not using the parallel feature, leave the PARALLEL pin open. cates 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. Thermal Considerations Introduction 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 18. PARALLEL SENSE(+) SENSE(–) VI(+) VO(+) VI(–) ON/OFF CASE VO(+) ON/OFF VI(+) VO(–) VI(–) SYNC IN VO(–) SYNC OUT 30.5 (1.20) CASE 82.6 (3.25) PARALLEL SENSE(+) SENSE(–) CASE MEASURE CASE TEMPERATURE HERE 8-1303 (C).a Note: Top view, measurements shown in millimeters and (inches). Pin locations are for reference only. VO(+) ON/OFF VI(+) VO(–) VI(–) Figure 18. Case Temperature Measurement Location 8-581 (C) Figure 17. 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 Ω) between PWR GOOD and SENSE(–) indicates that the module is operating. A high impedance (>1 MΩ) between PWR GOOD and SENSE(–) indi- Tyco Electronics Corp. 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). 11 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Data Sheet May 1999 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 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.). Derating curves for forced-air cooling without a heat sink are shown in Figures 19 and 20. 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 (θca) is defined as the maximum case temperature rise (∆TC, max) divided by the module power dissipation (PD): (TC – TA) C, max θ ca = ∆T = ------------------------------------------PD PD The location to measure case temperature (TC) is shown in Figure 18. Case-to-ambient thermal resistance vs. airflow for various heat sink configurations is shown in Figure 21 and Figure 22. 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 19. 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 Figure 21. Case-to-Ambient Thermal Resistance Curves; Transverse Orientation 10 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 20. Convection Power Derating with No Heat Sink; Airflow Along Length (Longitudinal) 12 Tyco Electronics Corp. Data Sheet May 1999 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Thermal Considerations (continued) Example If an 85 °C case temperature is desired, what is the minimum airflow necessary? Assume the FC250R module is operating at nominal line and an output current of 9.0 A, maximum ambient air temperature of 40 °C, and the heat sink is 0.5 inch. Heat Transfer With Heat Sinks (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 4.0 3.5 3.0 Solution Given: VI = 28 V IO = 9.0 A TA = 40 °C TC = 85 °C Heat sink = 0.5 inch. 2.5 2.0 1.5 1.0 0.5 0.0 Determine PD by using Figure 23: 0 0.5 (100) 1.0 (200) 1.5 (300) 2.0 (400) 2.5 (500) PD = 34 W 3.0 (600) Then solve the following equation: AIR VELOCITY, m/s (ft./min.) 8-1320 (C) TC – TA) θ ca = (----------------------PD - Figure 22. Case-to-Ambient Thermal Resistance Curves; Longitudinal Orientation 85 – 40 ) θ ca = (----------------------34 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 21 and 22 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. Figure 23 shows typical heat dissipation for a range of output currents and three voltages for the FC250R. POWER DISSIPATION, PD (W) 40 θ ca = 1.32 °C/W Use Figures 21 and 22 to determine air velocity for the 0.5 inch heat sink. The minimum airflow necessary for this module depends on heat sink fin orientation and is shown below: ■ 1.6 m/s (320 ft./min.) (oriented along width) ■ 2.0 m/s (400 ft./min.) (oriented along length) Custom Heat Sinks 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 (θcs) and sink-to-ambient (θsa) as shown in Figure 24. 35 30 25 20 VI = 36 V VI = 28 V VI = 18 V 15 10 PD TC TS cs 5 TA sa 8-1304 (C) 0 1 2 3 4 5 6 7 8 9 OUTPUT CURRENT, IO (A) Figure 24. Resistance from Case-to-Sink and Sinkto-Ambient 8-2471 (C) Figure 23. FC250R Power Dissipation vs. Output Current Tyco Electronics Corp. 13 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Thermal Considerations (continued) Data Sheet May 1999 Solder, Cleaning, and Drying Considerations Custom Heat Sinks (continued) For a managed interface using thermal grease or foils, a value of θcs = 0.1 °C/W to 0.3 °C/W is typical. The solution for heat sink resistance is: (TC – TA) θ sa = ------------------------- – θ 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. 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). EMC Considerations For assistance with designing for EMC compliance, please refer to the FLTR100V10 data sheet (DS98-152EPS). Layout Considerations Copper paths must not be routed beneath the power module mounting inserts. For additional layout guidelines, refer to the FLTR100V10 data sheet (DS98-152EPS). 14 Tyco Electronics Corp. Data Sheet May 1999 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W 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) 5.1 (0.20) MIN 1.57 ± 0.05 (0.062 ± 0.002) DIA SOLDER-PLATED BRASS, 11 PLCS (VOUT–, VOUT+, VIN–, VIN+) 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) 5.1 (0.20) 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) 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).a * Side label includes Tyco name, product designation, safety agency markings, input/output voltage and current ratings, and bar code. Tyco Electronics Corp. 15 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Data Sheet May 1999 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) 35.56 (1.400) 20.32 (0.800) 10.16 (0.400) 5.08 (0.200) VO– 25.40 (1.000) PWR GOOD CURRENT MON PARALLEL TRIM SENSE+ SENSE– 15.24 (0.600) 2.54 (0.100) TYP CASE SYNC OUT SYNC IN ON/OFF VI– VO+ 7.62 (0.300) 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).a Ordering Information Input Voltage 28 V 16 Output Voltage 28 V Output Power 250 W Device Code FC250R1 Comcode 107430316 Tyco Electronics Corp. Data Sheet May 1999 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Ordering Information (continued) Table 4. 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) 1 1/2 in. transverse kit (heat sink, thermal pad, and screws) 1 1/2 in. longitudinal kit (heat sink, thermal pad, and screws) 847308335 847308327 847308350 847308343 847308376 847308368 847308392 847308384 1/4 IN. 1/4 IN. 2.36 IN. 1/2 IN. 4.56 IN. 1/2 IN. 1 IN. 1 IN. 4.56 IN. 1 1/2 IN. 1 1/2 IN. D000-b.cvs 2.38 IN. D000-a.cvs Figure 26. Transverse Heat Sink Figure 25. Longitudinal Heat Sink Tyco Electronics Corp. 17 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Data Sheet May 1999 Notes 18 Tyco Electronics Corp. Data Sheet May 1999 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Notes Tyco Electronics Corp. 19 FC250R Power Module: dc-dc Converter; 18 Vdc to 36 Vdc Input, 28 Vdc Output; 250 W Data Sheet March 26, 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. © 2001 Tyco Electronics Corporation, Harrisburg, PA. All International Rights Reserved. Printed in U.S.A. May 1999 DS97-544EPS (Replaces DS95-158EPS) Printed on Recycled Paper