Data Sheet March 15, 2006 NaOSTM NXA025 SMT Non-isolated Power Modules: 10Vdc - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A Output Current RoHS Compliant Features Compliant to RoHS EU Directive 2002/95/EC (-Z versions) Compliant to ROHS EU Directive 2002/95/EC with lead solder exemption (non-Z versions) Delivers up to 25A output current High efficiency - 93% at 3.3V full load Small size and low profile: 47.2 mm x 29.4 mm x 8.50 mm (1.86 in x 1.16 in x 0.335 in) Applications Low output ripple and noise Constant switching frequency (500 kHz) Surface mount or through hole Output voltage programmable from 0.8 Vdc to 5.5Vdc via external resistor Distributed power architectures Intermediate bus voltage applications Remote On/Off Telecommunications equipment Remote Sense Servers and storage applications Parallel operation with current sharing (-P option) Networking equipment Output voltage sequencing (multiple modules) Enterprise Networks Output overvoltage protection Latest generation IC's (DSP, FPGA, ASIC) and Microprocessor powered applications Overtemperature protection Output overcurrent protection (non-latching) Options Baseplate version for heatsink attachment Wide operating temperature range (-40C to 85C) UL* 60950-1Recognized, CSA C22.2 No. 60950-1 03 Certified, and VDE 0805:2001-12 (EN60950-1) Licensed ISO** 9001 and ISO 14001 certified manufacturing facilities (-H suffix) Through Hole version (-L) Paralleling with current sharing (-P) Description The NXA025 series SMT (surface-mount technology) power modules are non-isolated dc-dc converters that can deliver up to 25A of output current with full load efficiency of 93% at 3.3Vdc output voltage. These modules provide a precisely regulated output voltage from 0.8Vdc to 5.5Vdc, programmable via an external resistor. Their openframe construction and small footprint enable designers to develop cost- and space-efficient solutions. Standard features include remote On/Off, adjustable output voltage, remote sense, active current sharing between parallel modules, output voltage sequencing of multiple modules, overcurrent, overvoltage, and overtemperature protection. * 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. ** ISO is a registered trademark of the International Organization of Standards Document No: DS03-030 ver. 1.4 PDF name: nxa025_10-14_smt.pdf Data Sheet March 15, 2006 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current 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 the device reliability. Parameter Device Symbol Min Max Unit All VIN -0.3 14 Vdc All TA -40 85 C All Tstg -55 125 C Input Voltage Continuous Operating Ambient Temperature (see Thermal Considerations section) Storage Temperature Electrical Specifications Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature conditions. Parameter Device Symbol Min Typ Max Unit Operating Input Voltage All VIN 10.0 12.0 14.0 Vdc Maximum Input Current All IIN,max 14 Adc Inrush Transient All I 2t 1 A2s Input Reflected Ripple Current, peak-to-peak (5Hz to 20MHz, 1H source impedance; VIN, min to VIN, max, IO= IOmax ; See Test configuration section) All 60 Input Ripple Rejection (120Hz) All 50 (VIN=10.0V to 14.0V, IO=IO, max ) mAp-p dB CAUTION: This power module is not internally fused. An input line fuse must always be used. This power module can be used in a wide variety of applications, ranging from simple standalone operation to being part of a complex 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 fastacting fuse with a maximum rating of 30A (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 sheet for further information. Tyco Electronics Power Systems 2 Data Sheet March 15, 2006 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Electrical Specifications (continued) Parameter Output Voltage Set-point Device Symbol Min Typ Max Unit All VO, set -1.2 +1.2 % VO, set All VO, set -3.0 +3.0 % VO, set All VO 0.7887 5.5 Vdc (VIN=VN, min, IO=IO, max, TA=25C) Output Voltage (Over all operating input voltage, resistive load, and temperature conditions until end of life) Adjustment Range Selected by an external resistor Output Regulation Line (VIN=VIN, min to VIN, max) All 0.01 0.1 % VO, set Load (IO=IO, min to IO, max) All 0.1 0.2 % VO, set Temperature (Tref =TA, min to TA, max) All 0.5 1 % VO, set RMS (5Hz to 20MHz bandwidth) All 5 15 mVrms Peak-to-Peak (5Hz to 20MHz bandwidth) All 15 50 mVpk-pk Output Ripple and Noise on nominal output (VIN=VIN, nom and IO=IO, min to IO, max Cout = 2 * 0.47F ceramic capacitors) External Capacitance ESR 1 m All CO, max 1000 F ESR 10 m All CO, max 10,000 F Output Current All Io 0 25 Adc Output Current Limit Inception (Hiccup Mode ) All IO, lim 125 150 % Io Output Short-Circuit Current All IO, s/c 1 Adc (VO250mV) ( Hiccup Mode ) Efficiency VIN= VIN, nom, TA=25C IO=IO, max , VO= VO,set Switching Frequency VO,set = 0.8Vdc 79.0 % VO, set = 1.2Vdc 84.7 % VO,set = 1.5Vdc 87.3 % VO,set = 1.8Vdc 88.9 % VO,set = 2.0Vdc 89.7 % VO,set = 2.5Vdc 91.4 % VO,set = 3.3Vdc 93.1 % VO,set = 5.5Vdc 95.1 All fsw All Vpk 500 % kHz 150 mV Dynamic Load Response (dIo/dt=5A/s; VIN = VIN, nom; TA=25C) Load Change from Io= 50% to 100% of Io,max; No external output capacitors Peak Deviation Settling Time (Vo<10% peak deviation) All ts (dIo/dt=5A/s; VIN = VIN, nom; TA=25C) All Vpk All ts 25 s 150 mV s Load Change from Io= 100% to 50%of Io,max: No external output capacitors Peak Deviation Settling Time (Vo<10% peak deviation) Tyco Electronics Power Systems 25 3 Data Sheet March 15, 2006 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current General Specifications Parameter Min Calculated MTBF (IO=80% of IO, max, TA=25C) Typ Max Unit 2,150,000 Weight Hours 15.5 (0.55) 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 Device Symbol Min Typ Max Unit SEQ/ENA Signal Interface (VIN=VIN, min to VIN, max ; open collector or equivalent, Signal referenced to GND) Logic High (SEQ/ENA pin open - Module Off) SEQ/ENA Current All ISEQ/ENA 0.5 2.33 mA SEQ/ENA Voltage: All VSEQ/ENA 3.5 14 V All ISEQ/ENA 200 A Logic Low (Module ON) SEQ/ENA Current: All VSEQ/ENA 1.2 V Turn-On Delay and Rise Times All Tdelay 1 msec (IO=IO, max , Vo to within 1% of steady state) All Trise 5 msec 0.1 0.5 % VO, set 5.8 6.0 V SEQ/ENA Voltage: Output voltage overshoot - Startup IO=80% of IO, max; VIN = 12Vdc, TA = 25 oC Ouptut Overvoltage Protection (Latching) All 5.62 Input Undervoltage Lockout Turn-on Threshold All Turn-off Threshold All Remote Sense Range Overtemperature Protection All 9.9 8.1 Tref V V 0.5 V 125 C 10 (See Thermal Consideration section) Forced Load Share Accuracy Number of units in Parallel Tyco Electronics Power Systems All % Io 5 4 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Data Sheet March 15, 2006 Characteristic Curves The following figures provide typical characteristics for the NXA025A0X -S at 25C. 88% 94% 87% 93% EFFICIENCY, (%) EFFICIENCY, (%) 86% 85% 84% Vin=13.2V 83% Vin=12.0V 82% Vin=10.8V 81% 80% 0 5 10 15 20 92% 91% Vin=13.2V 90% Vin=12.0V 89% Vin=10.8V 88% 25 0 OUTPUT CURRENT, IO (A) 95% 94% 89% EFFICIENCY, (%) EFFICIENCY, (%) 91% 88% 87% Vin=13.2V Vin=12.0V Vin=10.8V 84% 83% 20 25 93% 92% Vin=13.2V 91% Vin=12.0V 90% Vin=10.8V 89% 88% 0 5 10 15 20 25 0 OUTPUT CURRENT, IO (A) 5 10 15 20 25 OUTPUT CURRENT, IO (A) Figure 2. Converter Efficiency versus Output Current (Vout = 1.5Vdc). Figure 5. Converter Efficiency versus Output Current (Vout = 3.3Vdc). 92% 97% 91% 96% 95% 90% EFFICIENCY, (%) EFFICIENCY, (%) 15 Figure 4. Converter Efficiency versus Output Current (Vout = 2.5Vdc). 90% 85% 10 OUTPUT CURRENT, IO (A) Figure 1. Converter Efficiency versus Output Current (Vout = 1.2Vdc). 86% 5 89% 88% Vin=13.2V 87% Vin=12.0V 86% Vin=10.8V 85% 0 5 10 15 20 25 OUTPUT CURRENT, IO (A) Figure 3. Converter Efficiency versus Output Current (Vout = 1.8Vdc). Tyco Electronics Power Systems 94% Vin=13.2V 93% Vin=12.0V 92% Vin=10.8V 91% 90% 89% 0 5 10 15 20 25 OUTPUT CURRENT, IO (A) Figure 6. Converter Efficiency versus Output Current (Vout = 5.0Vdc). 5 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Data Sheet March 15, 2006 Characteristic Curves (continued) Tyco Electronics Power Systems VO (V) (50mV/div) IO (A) (5A/div) OUTPUT CURRENT, OUTPUT VOLTAGE On/Off VOLTAGE TIME, t (5s/div) Figure 9. Transient Response to Dynamic Load Change from 50% to 100% of full load (Vo = 3.3Vdc). VIN (V) (2V/div) Vo (V) (1V/div) TIME, t (0.5ms/div) Figure 11. Typical Start-Up with application of Vin (Vo = 3.3Vdc). OUTPUT VOLTAGE OUTPUT CURRENT OUTPUT VOLTAGE IO (A) (5A/div) VO (V) (50mV/div) Figure 8. Typical Output Ripple and Noise (Vin = 12V dc, Vo = 1.2Vdc, Cout = 2x 0.47uF ceramic capacitor). OUTPUT VOLTAGE, INPUT VOLTAGE VO (V) (20mV/div) OUTPUT VOLTAGE TIME, t (1s/div) TIME, t (5 s/div) Figure 10. Transient Response to Dynamic Load Change from 100% to 50% of full load (Vo = 3.3Vdc). VOn/off (V) (2V/div) TIME, t (1s/div) Figure 7. Typical Output Ripple and Noise (Vin = 12V dc, Vo = 3.3 Vdc, Cout = 2x 0.47uF ceramic capacitor). VOV) (1V/div) VO (V) (20mV/div) OUTPUT VOLTAGE The following figures provide typical characteristics for the NXA025A0X -S at 25C. TIME, t (0.5ms/div) Figure 12. Typical Start-Up Using Enable (Vo = 3.3Vdc). 6 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Data Sheet March 15, 2006 Characteristic Curves (continued) o Module #2 VO (V) (1V/div) Module # 1 VO(V) (1V/div) The following figures provide typical characteristics for the NXA025A0X -S at 25 C. TIME, t (1ms/div) VO(V) (1V/div) Module #2 Module # 1 VO (V) (1V/div) Figure 13. Synchronized Start-up of Output Voltage when SEQ/ENA pins are tied together (Module #1 = 1.5Vdc, Module #2 = 3.3Vdc). TIME, t (1ms/div) Figure 14. Synchronized Shut-down of Output Voltage when SEQ/ENA pins are tied together (Module #1 = 1.5Vdc, Module #2 = 3.3Vdc). Tyco Electronics Power Systems 7 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Data Sheet March 15, 2006 Characteristic Curves (continued) The following figures provide typical thermal derating curves for NXA025A0X -S (Figures 19 and 20 show derating curves with base plate). 30 30 OUTPUT CURRENT, Io (A) OUTPUT CURRENT, Io (A) 25 100LFM 20 200LFM 15 300LFM 10 400LFM 5 0 20 30 40 50 60 70 80 25 100LFM 20 200LFM 15 300LFM 10 400LFM 5 0 20 AMBIENT TEMPERATURE, TA OC 60 70 80 30 25 100LFM 20 200LFM 15 300LFM 10 400LFM 5 20 30 40 50 60 70 80 OUTPUT CURRENT, Io (A) OUTPUT CURRENT, Io (A) 50 Figure 18. Derating Output Current versus Local Ambient Temperature and Airflow (Vin = 12Vdc, Vo=5.0 Vdc). 30 25 20 15 10 100 LFM 5 200 LFM 0 20 AMBIENT TEMPERATURE, TA OC 30 40 50 60 70 80 AMBIENT TEMPERATURE, TA OC Figure 19. Derating Output Current versus Local Ambient Temperature and Airflow (Vin = 12Vdc, Vo=3.3 Vdc) with baseplate. Figure 16. Derating Output Current versus Local Ambient Temperature and Airflow (Vin = 12Vdc, Vo=1.8 Vdc). 30 25 100LFM 20 200LFM 15 300LFM 10 400LFM 5 0 20 30 40 50 60 70 O AMBIENT TEMPERATURE, TA C Figure 17. Derating Output Current versus Local Ambient Temperature and Airflow (Vin = 12Vdc, Vo=3.3 Vdc). Tyco Electronics Power Systems 80 OUTPUT CURRENT, Io (A) 30 OUTPUT CURRENT, Io (A) 40 AMBIENT TEMPERATURE, TA OC Figure 15. Derating Output Current versus Local Ambient Temperature and Airflow (Vin = 12Vdc, Vo=1.2Vdc). 0 30 25 20 100 LFM 15 200 LFM 10 300 LFM 5 400 LFM 0 20 30 40 50 60 70 80 O AMBIENT TEMPERATURE, TA C Figure 20. Derating Output Current versus Local Ambient Temperature and Airflow (Vin = 12Vdc, Vo=5.0 Vdc) with baseplate. 8 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Data Sheet March 15, 2006 Test Configurations Typical Application Circuit CIN LTEST Vin Rx VIN(+) 1H Share 4.99k Min 150F Vout SEQ/ENA Vout Vout Cout NOTE: Measure input reflected ripple current with a simulated source inductance (LTEST) of 1H. Capacitor CS offsets possible battery impedance. Measure current as shown above. GND SEN- Qx COM GND E.S.R.<0.1 @ 20C 100kHz SEN+ Dx CIN 220F Vin Share GND CS Rtrim BATTERY VIN CURRENT PROBE TO OSCILLOSCOPE 1uF Figure 21. Input Reflected Ripple Current Test Setup. Figure 24. Application Schematic COPPER STRIP V O (+) RESISTIVE LOAD 1uF . 10uF Input Source Impedance SCOPE COM GROUND PLANE NOTE: All voltage measurements to be taken at the module terminals, as shown above. If sockets are used then Kelvin connections are required at the module terminals to avoid measurement errors due to socket contact resistance. Figure 22. Output Ripple and Noise Test Setup. Rdistribution Rcontact Rcontact VIN(+) Rdistribution RLOAD VO Rcontact Rcontact COM Rdistribution VO VIN Rdistribution COM NOTE: All voltage measurements to be taken at the module terminals, as shown above. If sockets are used then Kelvin connections are required at the module terminals to avoid measurement errors due to socket contact resistance. Figure 23. Output Voltage and Efficiency Test Setup. VO. IO Efficiency = VIN. IIN x Tyco Electronics Power Systems 100 % Design Considerations The power module should be connected to a low-impedance source. Highly inductive source impedance can affect the stability of the power module. The input capacitor CIN should be located equal distance from the two input pins of the module. CIN is recommended to be 150F minimum. The ripple voltage is 50mV RMS at 1MHz and the capacitor should be chosen with an ESR and an RMS Current Rating for this amount of ripple voltage. When using multiple modules in parallel, a small inductor (0.2 -0.5H) is recommended at the input of each module to prevent interaction between modules. Consult the factory for further application guidelines. Safety Considerations For safety agency approval the power module must be installed in compliance with the spacing and separation requirements of the end-use safety agency standards, i.e., UL 60950-1, CSA C22.2 No. 60950-1-03, and VDE 0850:2001-12 (EN60950-1) Licensed. 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. The input to these units is to be provided with a maximum of 30 A fast-acting fuse in the ungrounded lead. 9 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Data Sheet March 15, 2006 Feature Description Remote On/Off using SEQ/ENA Pin The NXA025A0X-S SMT power modules feature an SEQ/ENA pin for remote On/Off operation. If not using the remote On/Off pin, leave the pin open (module will be on). The SEQ/ENA signal (VSEQ/ENA) is referenced to ground. Circuit configuration for remote On/Off operation of the module using SEQ/ENA pin is shown in Figure 25. During Logic High on the SEQ/ENA pin (transistor Qx is OFF), the module remains OFF. The external resistor Rx should be chosen to maintain 3.5V minimum on the SEQ/ENA pin to insure that the unit is OFF when transistor Qx is in the OFF state. During Logic-Low when Qx is turned ON, the module is turned ON. Note that the external diode is required to make sure the internal thermal shutdown (THERMAl_SD) and undervoltage (UVLO) circuits are not disabled when Qx is turned ON voltage at the point of load, connect SENSE (+) to Vo(+) and Sense (-) to ground. The amount of power delivered by the module is defined as the voltage at the output terminals multiplied by the output current. When using the remote sense, the output voltage of the module can be increased, which at the same output current would increase the power output of the module. Ensure that the maximum output power of the module remains at or below the maximum rated power (Po,max = Io,max x Vo,max). Figure 26. Effective Circuit Configuration for Remote sense operation Overcurrent Protection THERMAL_SD VIN UVLO Rx 4.99k Enable SEQ/ENA Pin Dx R1 1k Input Undervoltage Lockout R2 Qx 4.99k Figure 25. Remote On/Off Implementation. The SEQ/ENA pin can also be used to synchronize the output voltage start-up and shutdown of multiple modules in parallel. By connecting SEQ/ENA pins of multiple modules, the output start-up can be synchronized (please refer to characterization curves). When SEQ/ENA pins are connected together, all modules will shutdown if any one of the modules gets disabled due to undervoltage lockout or overtemperature protection. Remote Sense Remote sense feature minimizes the effects of distribution losses by regulating the voltage at the remote sense pins. The voltage between the remote sense pins and the output terminals must not exceed the remote sense range given in the Feature Specification table, i.e.: [Vo(+) - Vo(GND)] -[SENSE(+) - SENSE(-)] < 0.5V Remote sense configuration is shown in Figure 26. If not using the remote sense feature to regulate the output Tyco Electronics Power Systems To provide protection in a fault (output overload) condition, the unit is equipped with internal current-limiting circuitry and can endure current limiting continuously. At the point of current-limit inception, the unit enters hiccup mode. The unit operates normally once the output current is brought back into its specified range. The average output current during hiccup is 10% IO, max. At input voltages below the input undervoltage lockout limit, module operation is disabled. The module will begin to operate at an input voltage above the undervoltage lockout turn-on threshold. Overtemperature Protection To provide protection in a fault condition, the unit is equipped with a thermal shutdown circuit. The unit will shutdown if the thermal reference point Tref, exceeds o 125 C (typical), but the thermal shutdown is not intended as a guarantee that the unit will survive temperatures beyond its rating. The module will automatically restarts after it cools down. Output Voltage Programming The output voltage of the NXA025A0X-S can be programmed to any voltage from 0.8Vdc to 5.5Vdc by inserting a series resistor (shown as Rtrim in figure 27) in the Sense(+) pin of the module. Without an external resistor in the Sense(+) pin (Sense (+) pin is shorted to Vo(+)), the output voltage of the module will be 0.7887V. With Sense(+) not connected to Vo(+), the output of the module will reach overvoltage shutdown. A 1F multilayer ceramic capacitor is required from Rtrim to Sense(-) pin to minimize noise. To calculate the value of the 10 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Data Sheet March 15, 2006 Feature Descriptions (continued) Output Voltage Programming (continued) resistor Rtrim for a particular desired voltage Vo, use the following equation: Vo Rtrim = 775 * - 1 0 . 7887 Where Vo is the desired output voltage and Rtrim is the external resistor in ohms For example, to program the output voltage of the NXA025A0X-S module to 2.5Vdc, Rtrim is calculated as follows: 2.5 - 1 Rtrim = 775 * 0.7887 Rtrim = 1682 VIN(+) VO Rtrim Share 1F For additional power requirements, the power module can be configured for parallel operation with forced load sharing (See Figure 28). Good layout techniques should be observed for noise immunity when using multiple units in parallel. To implement forced load sharing, the following connections should be made: * The share pins of all units in parallel must be connected together. The path 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 the SENSE(+) pins to the (+) side of the bus and all the SENSE(-) pins to the GROUND of the power bus at the same point. Close proximity and directness are necessary for good noise immunity The share bus is not designed for redundant operation and the system will be non-functional upon failure of one of the unit when multiple units are in parallel. The maximum number of modules tied to share bus is 5. When not using the parallel feature, leave the share pin open. Sense+ ENA Forced Load sharing (Parallel Operation) RLOAD SenseCOM COM Figure 27. Circuit Configuration for Programming Output voltage Table 1 provides Rtrim values required for most common output voltages. To achieve the output voltage tolerance as specified in the electrical specifications over all operating input voltage, resistive load and temperature conditions, use 0.1% thick metal film resistor. Table 1 Vo,set Rtrim (V) 0.8 11 1.0 208 1.2 404 1.5 699 1.8 994 2.0 1190 2.5 1682 3.3 2468 5.0 4138 Overvoltage Shutdown Open Tyco Electronics Power Systems Figure 28. Circuit Configuration for modules in parallel. 11 Data Sheet March 15, 2006 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Thermal Considerations layout is shown in the mechanical section. In addition to the input and output planes, a ground plane beneath the module is recommended. The power modules operate in a variety of thermal environments; however, sufficient cooling should be provided to help ensure reliable operation. Considerations include ambient temperature, airflow, module power dissipation, and the need for increased reliability. A reduction in the operating temperature of the module will result in an increase in reliability. The thermal data presented here is based on physical measurements taken in a wind tunnel. The thermal reference point, Tref used in the specifications is shown in Figure 29. For reliable o operation this temperature should not exceed 110 C. Tref Tref Figure 29. Tref Temperature measurement location. Heat Transfer via Convection Increased airflow over the module enhances the heat transfer via convection. Derating figures showing the maximum output current that can be delivered by various module versus local ambient temperature (TA) for natural convection and up to 2m/s (400 ft./min) are shown in the respective Characteristics Curves section. Base-Plate option (-H) The baseplate option (-H) power modules are constructed with baseplate on topside of the open frame power module. The baseplate includes two through-threaded, M3 x 0.5 mounting hole pattern, 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.) during heat sink assembly. The baseplate option allows customers to operate the module in an extreme thermal environment with attachment of heatsink/cold-plate for proper cooling of internal component to heighten reliable and consistent operation. The thermal reference point for baseplate option is center of the heat plate on the top-side. For reliable operation this temperature should not exceed 105oC. Layout Considerations The input capacitors should be located equal distance from the two input pins of the module. Recommended Tyco Electronics Power Systems 12 Data Sheet March 15, 2006 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Mechanical Outline for NXA025A0X-S Dimensions are in inches and (millimeters). Tolerances: x.xx in. 0.02 in. (x.x mm 0.5 mm) [unless otherwise indicated] x.xxx in 0.010 in. (x.xx mm 0.25 mm) Top View Side View Bottom View Pin # Function 1 Ground 2 Vout 3 Ground 4 Vout 5 Ground 6 Vin 7 SHARE 8 Sen+ 9 SEQ/ENA 10 Sen- 11 Vin Tyco Electronics Power Systems 13 Data Sheet March 15, 2006 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Mechanical Outline for NXA025A0X-HS Dimensions are in inches and (millimeters). Tolerances: x.xx in. 0.02 in. (x.x mm 0.5 mm) [unless otherwise indicated] x.xxx in 0.010 in. (x.xx mm 0.25 mm) Top View For additional heat sink Attachment: Accepts M3x0.5 carbon steel screws Insertion into baseplate not to exceed 4.55 mm [0.175 in]. Max Torque = 5 IN-LBS Side View Bottom View Pin # Function 1 Ground 2 Vout 3 Ground 4 Vout 5 Ground 6 Vin 7 SHARE 8 Sen+ 9 SEQ/ENA 10 Sen- 11 Vin Tyco Electronics Power Systems 14 Data Sheet March 15, 2006 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Recommended Pad Layout Dimensions are in inches and (millimeters). Tolerances: x.xx in. 0.02 in. (x.x mm 0.5 mm) [unless otherwise indicated] x.xxx in 0.010 in. (x.xx mm 0.25 mm) Layout Guidelines Tyco Electronics Power Systems 15 Data Sheet March 15, 2006 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Mechanical Outline for NXA025A0X-L Dimensions are in inches and (millimeters). Tolerances: x.xx in. 0.02 in. (x.x mm 0.5 mm) [unless otherwise indicated] x.xxx in 0.010 in. (x.xx mm 0.25 mm) Top View Side View Bottom View Pin # Function 1 Ground 2 Vout 3 Ground 4 Vout 5 Ground 6 Vin 7 SHARE 8 Sen+ 9 SEQ/ENA 10 Sen- 11 Vin Tyco Electronics Power Systems 16 Data Sheet March 15, 2006 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Recommended Pad Layout for NXA025A0X-L (Through Hole Version) Dimensions are in millimeters and (inches). Tolerances: x.x mm 0.5 mm (x.xx in. 0.02 in.) [unless otherwise indicated] x.xx mm 0.25 mm (x.xxx in 0.010 in.) Tyco Electronics Power Systems 17 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Data Sheet March 15, 2006 Surface Mount Information Packaging Details Pick and Place The surface mount versions of the NXA025-S series modules are supplied as standard in the plastic tray shown in Figure 30. The tray has external dimensions of 136mm (W) x 322.6mm (L) x 18.4mm (H) or 5.35in (W) x 12.7in (L) x 0.72in (H). The NXA025-S series of DC-to-DC power modules use an open-frame construction and are designed for surface mount assembly within a fully automated manufacturing process. The NXA025-S series modules are fitted with two Kapton labels designed to provide a large flat surface for pick and placing. The labels are located covering the Center of Gravity of the power module. The labels meets all the requirements for surface-mount processing, as well as meeting UL safety agency standards. The labels will withstand reflow temperatures up to 300C. The labels also carry product information such as product code, date and location of manufacture. One of the two labels may be used as a pick-and-place location. Figure 31. Pick and Place Location. Nozzle Recommendations Figure 30. Surface Mount Packaging Tray Tray Specification Material Max temperature Antistatic coated PVC 65oC Max surface resistivity 1012/sq Color Capacity Min order quantity Clear 15 power modules 45 pcs (1box of 3 full trays) Each tray contains a total of 15 power modules. The trays are self-stacking and each shipping box will contain 3 full trays plus one empty hold down tray giving a total number of 45 power modules. Tyco Electronics Power Systems The module weight has been kept to a minimum by using open frame construction. Even so, they have a relatively large mass when compared with conventional SMT components. Variables such as nozzle size, tip style, vacuum pressure and placement speed should be considered to optimize this process. The minimum recommended nozzle diameter for reliable operation is 6mm. The maximum nozzle outer diameter, which will safely fit within the allowable component spacing, is 9 mm. Oblong or oval nozzles up to 11 x 9 mm may also be used within the space available. For further information please contact your local Tyco Electronics Power Systems Technical Sales Representative. 18 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Data Sheet March 15, 2006 Surface Mount Information (continued) 300 Reflow Soldering Information 250 These NXA025series power modules are large mass, low thermal resistance devices and typically heat up slower than other SMT components. It is recommended that the customer review data sheets in order to customize the solder reflow profile for each application board assembly. REFLOW TEMP (C) P eak Temp 235oC The following instructions must be observed when SMT soldering these units. Failure to observe these instructions may result in the failure of or cause damage to the modules, and can adversely affect long-term reliability. These surface mountable modules use our newest SMT technology called "Column Pin" (CP) connectors. Fig 32 shows the new CP connector before and after reflow soldering onto the end-board assembly. Co o ling zo ne 1-4oCs -1 Heat zo ne max 4oCs -1 200 150 So ak zo ne 30-240s 100 50 Tlim above 205oC P reheat zo ne max 4oCs -1 0 REFLOW TIME (S) Figure 32. Recommended Reflow Profile. 240 MAX TEMP SOLDER (C) 235 NXA Board Insulator Solder Ball End assembly PCB 230 225 220 215 210 205 200 Figure 32. Column Pin Connector Before and After Reflow Soldering. 0 10 20 30 40 50 60 TIME LIMIT (S) o Figure 33. Time Limit Curve Above 205 C Reflow. The CP is constructed from a solid copper pin with an integral solder ball attached, which is composed of tin/lead (Sn/Pb) solder. The CP connector design is able to compensate for large amounts of co-planarity and still ensure a reliable SMT solder joint. o Typically, the eutectic solder melts at 183 C, wets the land, and subsequently wicks the device connection. Sufficient time must be allowed to fuse the plating on the connection to ensure a reliable solder joint. There are several types of SMT reflow technologies currently used in the industry. These surface mount power modules can be reliably soldered using natural forced convection, IR (radiant infrared), or a combination of convection/IR. For reliable soldering the solder reflow profile should be established by accurately measuring the modules CP connector temperatures. Tyco Electronics Power Systems 19 Data Sheet March 15, 2006 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Surface Mount Information (continued) 300 Lead Free Soldering Peak Temp 260C 250 Reflow Temp (C) The -Z version Naos SMT modules are lead-free (Pbfree) and RoHS compliant and are both forward and backward compatible in a Pb-free and a SnPb soldering process. Failure to observe the instructions below may result in the failure of or cause damage to the modules and can adversely affect long-term reliability. Per J-STD-020 Rev. C 200 150 * Min. Time Above 235C 15 Seconds Heating Zone 1C/Second Cooling Zone *Time Above 217C 60 Seconds 100 50 Pb-free Reflow Profile Power Systems will comply with J-STD-020 Rev. C (Moisture/Reflow Sensitivity Classification for Nonhermetic Solid State Surface Mount Devices) for both Pb-free solder profiles and MSL classification procedures. This standard provides a recommended forced-air-convection reflow profile based on the volume and thickness of the package (table 4-2). The suggested Pb-free solder paste is Sn/Ag/Cu (SAC). The recommended linear reflow profile using Sn/Ag/Cu solder is shown in Fig. 34. 0 Reflow Time (Seconds) Figure 34. Recommended linear reflow profile using Sn/Ag/Cu solder. MSL Rating The Naos SMT modules have a MSL rating of 2. Storage and Handling The recommended storage environment and handling procedures for moisture-sensitive surface mount packages is detailed in J-STD-033 Rev. A (Handling, Packing, Shipping and Use of Moisture/Reflow Sensitive Surface Mount Devices). Moisture barrier bags (MBB) with desiccant are required for MSL ratings of 2 or greater. These sealed packages should not be broken until time of use. Once the original package is broken, the floor life of the product at conditions of 30C and 60% relative humidity varies according to the MSL rating (see J-STD-033A). The shelf life for dry packed SMT packages will be a minimum of 12 months from the bag seal date, when stored at the following conditions: < 40 C, < 90% relative humidity. Post Solder Cleaning and Drying Considerations Post solder cleaning is usually the final circuit-board assembly process prior to electrical board testing. The result of inadequate 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 Tyco Electronics Board Mounted Power Modules: Soldering and Cleaning Application Note (AP01-056EPS). Tyco Electronics Power Systems 20 NaosTM NXA025 SMT Non-isolated Power Modules: 10 - 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current Data Sheet March 15, 2006 Ordering Information Please contact your Tyco Electronics' Sales Representative for pricing, availability and optional features. Table 2. Device Codes Product codes Input Voltage Output Voltage Output Current Efficiency 3.3V @ 25A Connector Type Comcodes NXA025A0X-S 10 - 14 Vdc 0.8Vdc - 5.5Vdc 25 A 93 % SMT 108975053 NXA025A0X-HS 10 - 14 Vdc 0.8Vdc - 5.5Vdc 25 A 93 % SMT 108975061 NXA025A0X-L 10 - 14 Vdc 0.8Vdc - 5.5Vdc 25 A 93 % TH 108988515 NXA025A0X-LP 10 - 14 Vdc 0.8Vdc - 5.5Vdc 25 A 93 % TH CC109101350 NXA025A0X-SP 10 - 14 Vdc 0.8Vdc - 5.5Vdc 25 A 93 % SMT CC109101342 NXA025A0X-LPZ 10 - 14 Vdc 0.8Vdc - 5.5Vdc 25 A 93 % TH CC109106746 NXA025A0X-SZ 10 - 14 Vdc 0.8Vdc - 5.5Vdc 25 A 93 % SMT 109100402 NXA025A0X-HSZ 10 - 14 Vdc 0.8Vdc - 5.5Vdc 25 A 93 % SMT 109100393 NXA025A0X-LZ 10 - 14 Vdc 0.8Vdc - 5.5Vdc 25 A 93 % TH CC109107174 -Z refers to RoHS-compliant versions. Europe, Middle-East and Africa Headquarters Tyco Electronics (UK) Ltd Tel: +44 (0) 1344 469 300 Latin America, Brazil, Caribbean Headquarters Tyco Electronics Power Systems Tel: +56 2 209 8211 World Wide Headquarters Tyco Electronics Power Systems, Inc. 3000 Skyline Drive, Mesquite, TX 75149, USA +1-800-843-7497 (Outside U.S.A.: +1-972-284-2626) www.power.tycoelectronics.com e-mail: techsupport1@tycoelectronics.com India Headquarters Tyco Electronics Systems India Pte. Ltd. Tel: +91 80 841 1633 x3001 Asia-Pacific Headquarters Tyco Electronics Singapore Pte. Ltd. Tel: +65 6416 4283 Tyco Electronics Corporation 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) 2003 Tyco Electronics Power Systems, Inc., (Mesquite, Texas) All International Rights Reserved. Document No: DS03-030 ver. 1.4 PDF name: nxa025_10-14_smt.pdf