Technical Specification Non-Isolated SMT Converter 9.6 - 14.4Vin 16A 16A Non-Isolated, SMT DC/DC Converter with wide trim The NiQor™ SMT DC/DC converter is a non-isolated buck regulator, which employs synchronous rectification to achieve extremely high conversion effi- Non-Isolated ciency. The NiQor family of converters are used predominately in DPA systems using a front end DC/DC high power brick (48Vin to low voltage bus). The non-isolated NiQor converters are then used at the point of load to create the low voltage outputs required by the design. The wide trim module can be programmed to a variety of output voltages through the use of a single external resistor. Operational Features • Ultra-high efficiency, up to 95% at full and half load • Delivers 16 amps of output current with minimal derating - no heatsink required • Input voltage range: 9.6 - 14.4V • Programmable output voltages from 0.85 - 5.0V • On-board input and output filter capacitor • No minimum load requirement means no preload resistors required Protection Features • Input under-voltage lockout disables converter at low input voltage conditions • Temperature compensated over-current shutdown protects converter from excessive load current or short circuits • Output over-voltage protection protects load from damaging voltages • Thermal shutdown Product # NQ12T50SMA16 Phone 1-888-567-9596 NQ12T50SMA16 wide trim module Mechanical Features • Industry standard SMT pin-out configuration • Industry standard size: 1.3” x 0.53” x 0.29” (33 x 13.5 x 7.3 mm) • Total weight: 0.18 oz. (5 grams), lower mass greatly reduces vibration and shock problems • Open frame construction maximizes air flow cooling • Also available in SIP packaging Control Features • On/Off control • Remote sense • Output voltage trim (industry standard) permits custom voltages and voltage margining • Fixed output voltage modules available (0.9 - 5.0V) Safety Features • UL 1950 recognized (US & Canada) • TUV certified to EN60950 • Meets 72/23/EEC and 93/68/EEC directives which facilitates CE Marking in user’s end product • Board and plastic components meet UL94V-0 flammability requirements Doc.# 005-2NS12TE Rev. A 5/28/04 Page 1 Technical Specification Non-Isolated SMT Converter MECHANICAL DIAGRAM 9.6 - 14.4Vin 16A Surface Mount Package 0.288+.018 1.30 (7.32+0.45) (33.0) see Note 4 0.025 (0.64) 1 2 3 4 0.075 (1.91) 0.063 0.405 (1.60) (10.29) Typ. 0.53 (13.5) 6 5 0.012+.007 0.297 (0.3+0.17) (7.54) 0.100 (2.54) 0.487 0.048 (12.37) (1.22) 0.063 Bottomside Clearance (1.6) 0.677 Typ. (17.20) 0.867 Side View (22.02) 1.177 (29.90) Recommended SMT Pad Size: Minimum: 0.074” x 0.122” (1.88mm x 3.1mm) Maximum: 0.095” x 0.140” (2.41mm x 3.56mm) Bottom View NOTES SMT CONTACT DESIGNATIONS 1) SMT Contacts: Material - Brass Finish - Gold over Nickel plate 2) Undimensioned components are shown for visual reference only. 3) All dimensions in inches (mm) Tolerances: x.xx +/-0.02 in. (x.x +/-0.5mm) x.xxx +/-0.010 in. (x.xx +/-0.25mm) 4) Coplanarity for pins 1-6 is 0.004” max 5) Weight: 0.18 oz. (5 g) typical 6) Vertical and horizontal SIP pin options also available. 7) Workmanship: Meets or exceeds IPC-A-610C Class II Product # NQ12T50SMA16 Phone 1-888-567-9596 Pin No. Name Function 1 GND Ground 2 Vout(+) Positive output voltage 3 TRIM Output Voltage Trim 4 SENSE(+) Positive remote sense 5 Vin(+) Positive input voltage 6 ON/OFF Input to turn converter on/off Doc.# 005-2NS12TE Rev. A 5/28/04 Page 2 Technical Specification Non-Isolated SMT Converter 9.6 - 14.4Vin 16A ELECTRICAL CHARACTERISTICS - NQ12T50SMA16 Series TA=25°C, airflow rate=300 LFM, Vin=12Vdc unless otherwise noted; full operating temperature range is -40°C to +105°C ambient temperature with appropriate power derating. Specifications subject to change without notice. Parameter ABSOLUTE MAXIMUM RATINGS Input Voltage Non-Operating Operating Operating Temperature Storage Temperature Voltage at ON/OFF input pin INPUT CHARACTERISTICS Operating Input Voltage Range Input Under-Voltage Lockout Turn-On Voltage Threshold Turn-Off Voltage Threshold Lockout Hysteresis Maximum Input Current No-Load Input Current Disabled Input Current Inrush Current Transient Rating Response to Input Transient Input Reflected-Ripple Current Recommended Input Fuse Input Filter Capacitor Value Input Ripple Voltage Product # NQ12T50SMA16 Module Min. All All All All All 0 -40 -55 -3 All 9.6 All All All 0.9V 1.2V 1.5V 1.8V 2.5V 3.3V 5.0V 0.9V 1.2V 1.5V 1.8V 2.5V 3.3V 5.0V All All 0.9-2.5V 3.3V 5.0V 0.9V 1.2V 1.5V 1.8V 2.5V 3.3V 5.0V All All 0.9V 1.2V 1.5V 1.8V 2.5V 3.3V 5.0V 8.25 7.25 Phone 1-888-567-9596 Typ. Max. Units 16 14.4 105 125 15 V V °C °C V 12 14.4 V 8.75 7.75 1.0 9.2 8.1 V V V A A A A A A A A A A A A A A mA A 2s mV/V mV/V mV/V mA mA mA mA mA mA mA A µF mV mV mV mV mV mV mV 0.026 0.031 0.037 0.043 0.062 0.084 0.116 4 5 7.5 12.5 40 52 64 75 97 117 145 30 51 66 80 92 116 137 160 2.25 3.0 3.5 4.0 5.5 7.0 10.5 0.031 0.037 0.045 0.052 0.075 0.101 0.140 10 0.1 73 95 114 133 168 197 220 15 Notes & Conditions continuous continuous 9.6Vin, 100% Load, 10% trim up (all) with min. output capacitance 80V/ms input transient (all) pk-pk thru 1µH inductor; Fig 15-16 (all) fast blow external fuse recommended internal ceramic RMS, full load, Figures 15, 17 (all) Doc.# 005-2NS12TE Rev. A 5/28/04 Page 3 Technical Specification Non-Isolated SMT Converter 9.6 - 14.4Vin 16A ELECTRICAL CHARACTERISTICS (continued) - NQ12T50SMA16 Series Parameter OUTPUT CHARACTERISTICS Output Voltage Set Point Output Voltage Regulation Over Line Over Load Over Temperature Total Output Voltage Range Output Voltage Ripple and Noise (pk-pk\RMS) Operating Output Current Range Output DC Over-Current Shutdown Output Capacitance Range DYNAMIC CHARACTERISTICS Input Voltage Ripple Rejection Module Min. Typ. Max. Units 0.9V 1.2V 1.5V 1.8V 2.5V 3.3V 5.0V 0.888 1.184 1.481 1.777 2.468 3.257 4.935 0.900 1.200 1.500 1.800 2.500 3.300 5.000 0.912 1.216 1.520 1.823 2.533 3.343 5.065 V V V V V V V TBD TBD +0.50 3 mV mV % V V V V V V V mV mV mV A A µF All All All 0.9V 1.2V 1.5V 1.8V 2.5V 3.3V 5.0V 0.9-2.5V 3.3V 5.0V All All All 25\10 30\10 35\10 0 17 100 22 90 65 0.9V 5.0V Output Voltage during Load Current Transient For a Step Change in Output Current (0.1A/µs) All For a Step Change in Output Current (3A/µs) All Settling Time All Turn-On Transient Turn-On Time 0.9-1.5V 1.8-5.0V Output Voltage Overshoot All EFFICIENCY 100% Load 0.9V 1.2V 1.5V 1.8V 2.5V 3.3V 5.0V 50% Load 0.9V 1.2V 1.5V 1.8V 2.5V 3.3V 5.0V TEMP. LIMITS FOR POWER DERATING Semiconductor Junction Temperature All Board Temperature All Product # NQ12T50SMA16 0.882 1.176 1.470 1.764 2.450 3.234 4.900 7 +1.50 0.918 1.224 1.530 1.836 2.550 3.366 5.100 40\12 50\17 60\20 16 27 5,000 0.75 1 Phone 1-888-567-9596 40 100 50 75 1.5 2 0 2.5 3 1 83 86 88 89 92 93 94 87 89 91 91 93 94 95 12Vin; 50% load (all) with sense pin with sense pin, over sample, line, load, temperature & life (all) Full load;20MHz bandwidth; Figs 15, 18 Figure 23 >2.5 mW ESR dB dB 120 Hz; Figure 20 mV mV µs 50%-75%-50% Iout max, 100µF, Fig 13 50%-75%-50% Iout max, 470µF, Fig 14 ms ms % % % % % % % % % % % % % % % 125 125 Notes & Conditions °C °C to within 1.5% Vout nom., Figs 13-14 Figures 11-12 Full resistive load, Vout=100% nom. (all) resistive load Figures 1-4 Figures 1-4 Package rated to 150°C; Figs 5-10 UL rated max operating temp 130°C Doc.# 005-2NS12TE Rev. A 5/28/04 Page 4 Technical Specification Non-Isolated SMT Converter 9.6 - 14.4Vin 16A ELECTRICAL CHARACTERISTICS (continued) - NQ12T50SMA16 Series Parameter Module Min. Typ. Max. Units All 300 325 350 kHz 2.3 V V V kW % % % % °C °C FEATURE CHARACTERISTICS Switching Frequency ON/OFF Control Off-State Voltage On-State Voltage Pull-Up Voltage Pull-Up Resistance Output Voltage Trim Range Output Voltage Remote Sense Range Output Over-Voltage Protection All All All All All All 0.9V 1.2-5.0V Over-Temperature Shutdown All Over-Temperature Shutdown Restart Hysteresis All RELIABILITY CHARACTERISTICS Calculated MTBF (Telcordia) All Calculated MTBF (MIL-217) All Field Demonstrated MTBF All 2.65 Vin/2 10 -10 140 118 145 127 133 12 +10 +10 150 140 Notes & Conditions may drop by 10% at light load See Applications Information Measured Vout+ to common pins; Table 1 Measured Vout+ to common pins Over full temp range; % of nominal Vout Average PCB Temperature 106 Hrs. TR-NWT-000332; 100% load, 200LFM, 40oC Ta 106 Hrs. MIL-HDBK-217F; 100% load, 200LFM, 40oC Ta 106 Hrs. See website for latest values TBD TBD STANDARDS COMPLIANCE Parameter P Notes STANDARDS COMPLIANCE UL/cUL 60950 EN60950 72/23/EEC 93/68/EEC Needle Flame Test (IEC 695-2-2) IEC 61000-4-2 GR-1089-CORE Telcordia (Bellcore) GR-513 File # E194341 Certified by TUV test on entire assembly; board & plastic components UL94V-0 compliant ESD test, 8kV - NP, 15kV air - NP (Normal Performance) Section 7 - electrical safety, Section 9 - bonding/grounding • An external input fuse must always be used to meet these safety requirements. Contact SynQor for official safety certificates on new releases or download from the SynQor website. QUALIFICATION TESTING Parameter P QUALIFICATION TESTING Life Test Vibration Mechanical Shock Temperature Cycling Power/Thermal Cycling Design Marginality Humidity Solderability # Units 32 5 5 10 5 5 5 15 pins Test Conditions 95% rated Vin and load, units at derating point, 1000 hours 10-55Hz sweep, 0.060” total excursion,1 min./sweep, 120 sweeps for 3 axis 100g minimum, 2 drops in x and y axis, 1 drop in z axis -40°C to 100°C, unit temp. ramp 15°C/min., 500 cycles Toperating = min to max, Vin = min to max, full load, 100 cycles Tmin-10°C to Tmax+10°C, 5°C steps, Vin = min to max, 0-105% load 85°C, 85% RH, 1000 hours, continuous Vin applied except 5min./day MIL-STD-883, method 2003 • Extensive characterization testing of all SynQor products and manufacturing processes is performed to ensure that we supply robust, reliable product. Contact factory for official product family qualification document. OPTIONS PATENTS SynQor provides various options for Packaging, Enable Logic, and Feature Set for this family of DC/DC converters. Please consult the last page of this specification sheet for information on available options. SynQor is protected under various patents, including but not limited to U.S. Patent numbers: 5,999,417; 6,222,742 B1; 6,594,159 B2; 6,545,890 B2. Product # NQ12T50SMA16 Phone 1-888-567-9596 Doc.# 005-2NS12TE Rev. A 5/28/04 Page 5 Performance Curves Non-Isolated SMT Converter 95 95 90 90 Efficiency (%) 100 Efficiency (%) 100 85 80 5.0 Vo 3.3 Vo 2.5 Vo 1.8 Vo 1.5 Vo 1.2 Vo 0.9 Vo 75 70 65 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 85 5.0 Vo Min Line 5.0 Vo Max Line 1.8 Vo Min Line 1.8 Vo Max Line 1.2 Vo Min Line 1.2 Vo Max Line 80 75 70 65 15 16 0 1 2 3 Load Current (A) 93 3.5 92 3.0 Efficiency (%) Power Dissipation (W) 94 4.0 2.5 2.0 5.0 Vo 3.3 Vo 2.5 Vo 1.8 Vo 1.5 Vo 1.2 Vo 0.9 Vo 1.5 1.0 0.5 0.0 2 3 4 5 6 7 8 9 10 5 6 7 8 9 10 11 12 13 14 15 16 Figure 2: Efficiency at min and max line vs. load current for 1.2Vo, 1.8Vo and 5.0Vo units at 25°C. 4.5 1 4 Load Current (A) Figure 1: Efficiency at nominal output voltage vs. load current for nominal input voltage at 25°C. 0 9.6 - 14.4Vin 16A 11 12 13 14 15 91 90 89 88 25 C 55 C 87 85 C 86 16 0 100 200 300 400 500 Air Flow (LFM) Load Current (A) Figure 3: Power dissipation at nominal output voltage vs. load current for nominal input voltage at 25°C. Figure 4: Efficiency at 1.8Vout and 60% rated power vs. airflow rate for ambient air temperatures of 25°C, 55°C, and 85°C (nominal input voltage). 16 14 Iout (A) 12 10 8 6 Heavy CU board Typ Install, 6-Layer, 2 oz. (71um) CU board 4 300 LFM (1.5 m/s) free air 2 100 LFM (0.5 m/s) free air 0 0 25 40 55 70 85 Ambient Air Temperature (oC) Figure 5: Maximum output power derating curves for 0.9Vo, 1.2Vo, 1.5Vo units under various thermal conditions and nominal input voltage. See Thermal Considerations section for more details. Product # NQ12T50SMA16 Phone 1-888-567-9596 Semiconductor junction temperature is within 1°C of surface temperature Figure 6: Thermal plot of 0.9Vo, 1.2Vo, 1.5Vo converters at nominal Vin and 16 amp load current mounted on a 70°C, 6-Layer, 2 oz. copper board (typical installation). Doc.# 005-2NS12TE Rev. A 5/28/04 Page 6 Performance Curves Non-Isolated SMT Converter 9.6 - 14.4Vin 16A 16 14 Iout (A) 12 10 8 6 Heavy CU board Typ Install, 6-Layer, 2 oz. (71um) CU board 4 300 LFM (1.5 m/s) free air 2 100 LFM (0.5 m/s) free air 0 0 25 40 55 70 85 Ambient Air Temperature (oC) Figure 7: Maximum output power derating curves for 1.8Vo, 2.5Vo units under various thermal conditions and nominal input voltage. See Thermal Considerations section for more details. Semiconductor junction temperature is within 1°C of surface temperature Figure 8: Thermal plot of 1.8Vo, 2.5Vo converters at nominal Vin and 16 amp load current mounted on a 70°C, 6-Layer, 2 oz. copper board (typical installation). 16 14 Iout (A) 12 10 8 6 Heavy CU board Typ Install, 6-Layer, 2 oz. (71um) CU board 4 300 LFM (1.5 m/s) free air 2 100 LFM (0.5 m/s) free air 0 0 25 40 55 70 85 Ambient Air Temperature (oC) Figure 9: Maximum output power derating curves for 3.3Vo, 5.0Vo units under various thermal conditions and nominal input voltage. See Thermal Considerations section for more details. Figure 10: Thermal plot of 3.3Vo converter (16 amp load) and 5.0Vo converter (14.6 amp load). Both at nominal Vin and mounted on a 70°C, 6-Layer, 2 oz. copper board (typical installation). 5.0Vout 5.0Vout 3.3Vout 3.3Vout 2.5Vout 2.5Vout 1.8Vout 1.5Vout 1.2Vout 0.9Vout 1.8Vout 1.5Vout 1.2Vout 0.9Vout Figure 11: Turn-on transient at full load (resistive load) (400 µs/div). Ch 1: ON/OFF input (5V/div) Ch 2-8: Vout (1V/div) Product # NQ12T50SMA16 Semiconductor junction temperature is within 1°C of surface temperature Phone 1-888-567-9596 Figure 12: Turn-on transient at zero load (400 µs/div). Ch 1: ON/OFF input (5V/div) Ch 2-8: Vout (1V/div) Doc.# 005-2NS12TE Rev. A 5/28/04 Page 7 Performance Curves Non-Isolated SMT Converter 9.6 - 14.4Vin 16A 5.0Vout 5.0Vout 1.8Vout 1.8Vout 0.9Vout 0.9Vout 100µ s/div 100µ s/div Figure 13: Output voltage response for 0.9V, 1.8V, 5.0V units to step-change in load current (50-75-50% of Iout max; di/dt=0.1A/µ s). Load cap: 100µ F, 100mW ESR tant, 10µ F cer. Ch 1: Iout (5A/div), Ch 2-4: Vout (100mV/div). Figure 14: Output voltage response for 0.9V, 1.8V, 5.0V units to step-change in load current (50-75-50% of Iout max; di/dt=3A/µ s). Load cap: 470µ F, 25mW ESR tant, 10µ F cer. Ch 1: Iout (5A/div), Ch 2-4: Vout (100mV/div). See Fig. 16 1 µH source impedance 5.0Vout See Fig. 17 See Fig. 18 iS VSOURCE VIN C* DC/DC Converter VOUT 10 µF 3.3Vout 2.5Vout 1.8Vout 1.5Vout 1.2Vout 100 µF ceramic 100mW ESR capacitor tantalum capacitor * See values for recommended external input capacitance. Inductor optional as needed. Figure 15: Test set-up diagram showing measurement points for Input Reflected Ripple Current (Figure 16), Input Terminal Ripple Voltage (Figure 17), and Output Voltage Ripple (Figure 18). 0.9Vout 1 s/div Figure 16: Input Reflected Ripple Current, is, through a 1 µ H source inductor at nominal input voltage and rated load current (10 mA/div). See Figure 15. 5.0Vout 5.0Vout 3.3Vout 3.3Vout 2.5Vout 2.5Vout 1.8Vout 1.8Vout 1.5Vout 1.5Vout 1.2Vout 1.2Vout 0.9Vout 1 s/div Figure 17: Input Terminal Ripple Voltage at nominal input voltage and rated load current (200 mV/div). Load capacitance: 10µ F ceramic cap and 100µ F tantalum cap. Bandwidth: 20 MHz. See Figure 15. Product # NQ12T50SMA16 1 s/div 0.9Vout Phone 1-888-567-9596 Figure 18: Output Voltage Ripple at nominal input voltage and rated load current (20 mV/div). Load capacitance: 10µ F ceramic cap and 100µ F tantalum cap.. Bandwidth: 20 MHz. See Figure 15. Doc.# 005-2NS12TE Rev. A 5/28/04 Page 8 Performance Curves Non-Isolated SMT Converter 0.1 9.6 - 14.4Vin 16A 0 0.9 V 0.01 1.2 V 1.5 V 1.8 V 2.5 V 0.001 3.3 V 5.0 V Forward Transmission (dB) Output Impedance ( ) -10 -20 -30 0.9 V 1.2 V -40 1.5 V 1.8 V -50 -60 2.5 V -70 3.3 V 5.0 V -80 -90 -100 0.0001 -110 10 100 1,000 10,000 100,000 100 1,000 Hz 10,000 100,000 Hz Figure 19: Magnitude of incremental output impedance (Zout = vout/iout) for nominal input voltage at full rated power with 100µ F tantalum output capacitor. Figure 20: Magnitude of incremental forward transmission (FT = vout/vin) for nominal input voltage at full rated power with 100µ F tantalum output capacitor. 100 10 10 0 0.9 V 1.2 V -5 1.5 V 1.8 V 2.5 V -10 3.3 V 5.0 V -15 Input Impedance ( ) Reverse Transmission (dB) 5 0.9 V 1.2 V 1.5 V 1 1.8 V 2.5 V 3.3 V 0.1 5.0 V -20 -25 0.01 10 100 1,000 10,000 100,000 10 Hz 100 1,000 10,000 100,000 Hz Figure 21: Magnitude of incremental reverse transmission (RT = iin/iout) for nominal input voltage at full rated power with 100µ F tantalum output capacitor. Figure 22: Magnitude of incremental input impedance (Zin = vin/iin) for nominal input voltage at full rated power with 100µ F tantalum output capacitor. 6.0 Vout nominal Output Voltage (V) 5.0 4.0 3.0 Vout nom / 2 2.0 1.0 0.0 0 5 10 15 20 25 Load Current (A) Figure 23: Output voltage vs. load current showing current limit inception point and fold-back current limit behavior. Product # NQ12T50SMA16 Phone 1-888-567-9596 Doc.# 005-2NS12TE Rev. A 5/28/04 Page 9 Technical Specification Non-Isolated SMT Converter BASIC OPERATION AND FEATURES The NiQor series non-isolated converter uses a buck-converter that keeps the output voltage constant over variations in line, load, and temperature. The NiQor modules employ synchronous rectification for very high efficiency. Dissipation throughout the converter is so low that it does not require a heatsink or metal baseplate for operation. The NiQor converter can thus be built more simply and reliably using high yield surface mount techniques on a single PCB substrate. The NiQor series of SIPs and SMT converters uses the established industry standard footprint and pin-out configurations. CONTROL FEATURES REMOTE ON/OFF: The ON/OFF input permits the user to control when the converter is on or off. There is currently a single option available for the ON/OFF input described in the table below. Others may become available if demand exists. Option P Logic Description Positive/Open Pin-Open Float Voltage Vin / 2 Pin-Open Converter State On Pin Action Pull Low = Off OUTPUT VOLTAGE TRIM: The TRIM input permits the user to adjust the output voltage according to the trim range specifications by using an external resistor. If the TRIM feature is not being used, leave the TRIM pin disconnected. TRIM-UP: To increase the output voltage from the nominal setpoint of 0.7525V using an external resistor, connect the resistor Rtrim-up between the TRIM and the Ground pin according to the diagram below. Vout Sense+ Vin On/Off Gnd Trim Rtrim-up For a desired increase of the nominal output voltage, the value of the resistor should be: Rtrim-up = 9.6 - 14.4Vin 16A 10500 VDES - 0.7525 _ 1000 (W) or VOUT = 0.7525 + where 10500 Rtrim-up + 1000 (W) VDES = Desired Output Voltage To maintain the accuracy of the output voltage over load current, it is vital that any trim-up resistor be terminated directly to the converter's ground foot, not at the connection to the load. A separate Kelvin connection to the PCB pad for the ground foot is optimal. Trim-down resistors should be terminated at the converter's Sense+ pin. We do not recommend bypassing the trim pin directly to ground with a capacitor. The voltage gain from the trim pin to output is rather large, 15:1. Ground bounce through a bypass capacitor could introduce significant noise into the converter's control circuit. PROTECTION FEATURES Input Under-Voltage Lockout: The converter is designed to turn off when the input voltage is too low, helping avoid an input system instability problem, described in more detail in the application note titled “Input System Instability”. The lockout circuitry is a comparator with DC hysteresis. When the input voltage is rising, it must exceed the typical Turn-On Voltage Threshold value (listed on the specification page) before the converter will turn on. Once the converter is on, the input voltage must fall below the typical Turn-Off Voltage Threshold value before the converter will turn off. Output Current Limiting: The NQ12 family of converters employs foldback current limiting. A typical output voltage-current curve is shown in Figure 23 in the Performance Curves section. Current limit is reached at about 125% of rated current. Loads in excess of that limit will cause the output to droop. If the load is sufficient to pull the output down to roughly 1/2 of its nominal setpoint, foldback will ensue. From there, as the load is further increased, the output current will decrease linearly to about 1/3 of rated current at zero Vout. Thus, operating into a dead short, the unit will deliver 1/3 rated current indefinitely. This reduces stress on the converter and ensures that prolonged short-circuits will not overheat the converter. Since there is no "hiccup mode" to the current-limit operation, Product # NQ12T50SMA16 Phone 1-888-567-9596 Doc.# 005-2NS12TE Rev. A 5/28/04 Page 10 Technical Specification Non-Isolated SMT Converter there is also no concern with operation or startup into large capacitive loads. The voltage may rise slowly while charging the output capacitance, but it will rise. There are also no problems starting into a load that has a resistive V-I curve. As long as the load draws less than the current limit value at 1/2 of the unit's setpoint voltage, proper startup is ensured. 9.6 - 14.4Vin 16A APPLICATION CONSIDERATIONS Input Filtering/Capacitance/Damping: The filter circuit of Figure C is often added to the converter's input to prevent switching noise from reaching the input voltage bus. Internal Over-Voltage Protection: To fully protect from excessive output voltage, the NQ12 series contains two levels of Output Over-Voltage Shutdown circuitry. The first type monitors the output at the load via the Sense+ pin (or the output if Sense+ is left open). If the sensed voltage exceeds the (optionally trimmed) setpoint by ~10% this protective circuit asserts the converter's low-side switch until the output returns to normal. This circuit tracks the trimmed setpoint; the +10% threshold is maintained over the wide trim range of the T50 model. This circuit can also be benignly activated during the response to a large, fast drop in load current. In this instance the converter's normal transient response is momentarily overridden by this OVP. The result is a slight asymmetry in the converter's observed transient response. It should be noted that there is no limit on this OVP; if a powerful external source attempts to raise the output of an NQ12 converter beyond 110% of its setpoint, the converter will sacrifice itself trying to draw down that external source and protect its load from the overvoltage. The second Output Over-Voltage Shutdown circuit independently compares the voltage at the converter's output pin with that of a redundant reference. If the output ever exceeds ~125% of nominal setpoint, both converter switches are disabled. After the output voltage returns to normal, a softstart cycle is initiated. This OVP is independent of the trimmed setpoint. As such, the converter's load is protected from faults in the external trim circuitry (such as a trim pin shorted to ground). Since the setpoint of this OVP does not track trim, it is set at 125% of 5.0V, or 6.2V, in the wide-trim T50 model. Over-Temperature Shutdown: A temperature sensor on the converter senses the average temperature of the module. The thermal shutdown circuit is designed to turn the converter off when the temperature at the sensed location reaches the Over-Temperature Shutdown value. It will allow the converter to turn on again when the temperature of the sensed location falls by the amount of the Over-Temperature Shutdown Restart Hysteresis value. Product # NQ12T50SMA16 Phone 1-888-567-9596 Figure C: NQ12 converter with Input Filter In the SMA16 (surface mount) converters Cin = 30µF and in the VMA16 (SIP) converters Cin = 45µF of high quality ceramic capacitors. With Lin of 1µH, Cd should be 100-200µF and Rd should be 0.1-0.2W, in most applications. For more information on designing the input filter and choosing proper values, contact SynQor technical support. With the values listed above, the ripple current in L1 will be below 100mA RMS for all units. The full-load worst-case filter operation is summarized in Table 1. Vout Model 0.9 1.0 1.2 1.5 1.8 2.0 2.5 3.3 5.0 Current (A RMS) 5.2 5.5 6.0 6.7 7.4 7.8 8.8 10.4 12.3 Ripple (V RMS) 0.06 0.07 0.08 0.09 0.11 0.11 0.13 0.15 0.16 Current in L1 (mA RMS) 32 34 40 47 54 59 69 81 86 Vp Ripple (V RMS) 0.04 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.11 Current in L1 (mA RMS) 21 22 27 31 36 39 46 54 57 Table 1: Full Load Input Filter Performance, SMA16 Adding significant external pure ceramic capacitance directly across the converter's input pins is not recommended. Parasitic inductance associated with the input pin geometry and PCB traces can create a high-Q CLC circuit with any external capacitors. Just a few nano-Henries of parasitic inductance can create a resonance (or an overtone) near the converter's switching frequency. Cin has a reactance of 10-20mW at the 330kHz switching frequency. To avoid this high-frequency resonance, any external input filter should exhibit a net source impedance of at least 20mW resistive through this frequency range. This requirement is easily met with the damping elements discussed above. Adding a small amount (a few µF) of high-frequency external ceramic will not violate it. If using converters at higher powers, do consider the ripple current rating of Cd. Contact SynQor technical support for more Doc.# 005-2NS12TE Rev. A 5/28/04 Page 11 Technical Specification Non-Isolated SMT Converter 9.6 - 14.4Vin 16A information. Output Capacitance: It is recommended to add at least 100µF of capacitance, with an ESR in the 0.1W range, to the output of the SMA16 series of converters. The VMA16 series has this capacitance included internally. In many applications, however, additional external output capacitance is required to reduce the response to load transients to an allowable level. The output impedance of these converters can be quite accurately modeled from DC to about 100kHz as shown in Figure D. A further simplified version of it, valid below 40Hz and above 1kHz, is shown in Figure E. In the SMA16 case, the models depict the minimum recommended output capacitance, Ct with its resistance Rt. In the VMA16 family, that capacitor is again included in the converter. Figure D: NQ12 Passive Output Model If the dynamic characteristics of the load are known, any standard simulator can use these models to predict the in-circuit transient response. If the transients are Figure E: Simplified NQ12 Output Model current steps then Table 3 provides values for ESRd and Cd for different allowable responses. The allowable step response is normalized to a 1A step, and the maximum allowable value of ESRd can be read from the table. Figure F: Converter with Additional Output Capacitance For minimal overshoot upon recovery, Cd should be related to the minimum in-circuit net ESR. Cd > parallel (L1, L2) ESRdmin2 The third column in Table 3 gives Cdmin for a 40% reduction in ESR and the highest L1||L2 value in Table 2. For more detailed derivations of these values, contact SynQor technical support. Load Current Step Response Pk mV/Amp 23 19 14 9 5 External Capacitor ESRd max 0.1* 0.05 0.025 0.0125 0.00625 Cd min (uF) 100* 400 1,600 6,400 25,600 * Included in VMA, min recommended for SMA Table 3: External Capacitor Values for Different Step Responses Thermal Performance (SMA16): While it's impossible to be exact, a simplified thermal model for the mounted converter is detailed below. Figure G: Thermal Model for NQ12 Surface Mount Table 2: Component Values for Passive Output Models Product # NQ12T50SMA16 Phone 1-888-567-9596 • Rt_J-Pcb models the conduction of heat from the converter's Doc.# 005-2NS12TE Rev. A 5/28/04 Page 12 Technical Specification Non-Isolated SMT Converter hottest junction to the converter's PCB at large. It is about 3oC/W for converters running at higher output voltage, and about 4oC/W for lower voltage converters. pads. Solder mask should be used to eliminate solder wicking into the vias. Pick and Place: The NiQor surface mount modules are designed for automated assembly using standard SMT pick and place equipment. The modules have a centrally located inductor component with a flat surface area to be used for component pick-up. The units use open frame construction and have a low mass that is within the capability of standard pick and place equipment. Those modules however have a larger mass than most conventional SMT components and so variables such as nozzle size, tip style, handling speed, and placement pressure should be optimized for best results. A conformal tipped placement nozzle design is recommended. Coplanarity of better than 0.004" (0.1mm) is achieved through the SMT NiQor's terminal design. • Rt_Pcb-Amb models the power dissipation from converter PCB to the air stream. It ranges from about 15oC/W at 400LFM to about 25oC/W 100LFM. • Rt_Pcb-Feet expresses the thermal path from the converter's PCB though its mounting feet; it is about 3oC/W. • Rt_spread models the heat spreading on the PCB to which the converter is mounted and is largely dependent upon the construction and layout of that PCB. • T_mount is the temperature of that PCB in the greater vicinity of the converter. As is evident, the values for Rt_spread and T_mount will have great effect upon the thermal operation of the converter. With Rt_Pcb-Amb being 5 to 8 times as large as Rt_Pcb-Feet, in most applications these converters will be predominantly cooled via thermal conduction through their feet. Airflow and T_Amb will have only a minimal cooling effect. Reflow Soldering Guidelines: Figure H shows a typical reflow profile for a eutectic solder process. Due to variations in customer applications, materials and processes, it is not feasible for SynQor to recommend a specific reflow profile. The customer should use this profile as a guideline only. Since the NiQor surface mount modules have a larger thermal mass and lower thermal resistance than standard SMT components, it may be necessary to optimize the solder reflow profile based on limitations of the other components on the customer board. Sufficient reflow time must be allowed to fuse the plating on the connection to ensure a reliable solder joint. The solder reflow profile should be confirmed by accurately measuring the SMT interconnect leads. The guidelines illustrated in figure H must be observed to ensure the maximum case temperature of 260°C (exposure for 5 seconds or less) is not exceeded for the NiQor units. • Rt_spread should be minimized. Attach the converter to large copper planes, on multiple layers, with multiple vias near the mounting feet. • T_mount should also be minimized. Place the converter far enough away from other sources of heat on the PCB so that it is as cool as practical. • If operation near derating limits is even suspected, thermal performance should be verified with the unit mounted in its intended manner and powered in circuit with all neighboring circuitry active. Attach a thermocouple to the converter's hotspot as shown in Figures 6, 8, and 10 in the Performance Curves section. SURFACE MOUNT INFORMATION PCB Layout Considerations: SynQor recommends that the customer use a non-solder mask defined pad design. The minimum recommended pad size is 0.074" x 0.122" (1.88mm x 3.1mm) and the maximum pad size is 0.095" x 0.140" (2.41mm x 3.56mm), see mechanical diagram on page 2. Interconnection to internal power planes is typically required. This can be accomplished by placing a number of vias between the SMT pad and the relevant plane. The number and location of the vias should be determined based on electrical resistance, current and thermal requirements. "Via-inpad" design should be avoided in the SMT Product # NQ12T50SMA16 9.6 - 14.4Vin 16A Maximum Temperature (+210-260oC) Eutectic Solder Melting Point (+183oC) (+150-155oC) Pre-heat • Reflow Soak o < 2.5 C/sec • 0.5-0.6oC/sec • 1.3-1.6oC/sec • 60 to 90 sec., typ., 2 min max • 30 to 60 sec., typ., 90 sec max Cool Down 2 to 4 min. Figure H: Typical Eutectic (96.5Sn/3.0Ag/0.5Cu) Solder Profile Phone 1-888-567-9596 Doc.# 005-2NS12TE Rev. A 5/28/04 Page 13 Technical Specification Non-Isolated SMT Converter 9.6 - 14.4Vin 16A Lead-Free Soldering: The NiQor surface mount modules are manufactured with lead free solder and PCB finish and meet the conditions for Lead-Free 2 status. Users who wish to assemble the modules in a Lead Free solder process may require peak reflow temperatures exceeding 240°C. The maximum allowable case temperature of the surface mount NiQor modules is 260°C for no greater than 5 seconds. Moisture Sensitivity: The NiQor surface mount modules have an MSL rating 1 per IPC/JEDEC J-STD-033A. Cleaning and Drying: When possible, a no-clean solder paste system should be used to solder the NiQor SMT units to their application board. The modules are suitable for aqueous washing, however, the user must ensure sufficient drying to remove all water from the converter before powering up. Inadequate cleaning and drying can affect the reliability of the converter and the testing of the final assembly. Tape & Reel Packaging: The NiQor SMT modules are supplied in tape and reel packaging in quantities of 320 units per reel. Packaging conforms to EIA-481 standards. Tape and reel dimensions are shown in the diagram below. 330 mm (13”) diameter reel Tape View Leader: 400 mm min. thermally sealed cover tape Direction of feed Pin 1 location Trailer: 160 mm min. product information 44 mm 24 mm carrier tape Reel View Product # NQ12T50SMA16 Phone 1-888-567-9596 Doc.# 005-2NS12TE Rev. A 5/28/04 Page 14 Technical Specification Non-Isolated SMT Converter 9.6 - 14.4Vin 16A PART NUMBERING SYSTEM ORDERING INFORMATION The part numbering system for SynQor’s NiQor DC/DC converters follows the format shown in the example below. The tables below show the valid model numbers and ordering options for converters in this product family. When ordering SynQor converters, please ensure that you use the complete 15 character part number consisting of the 12 character base part number and the additional 3 characters for options. NQ 12 T50 S M A 16 P S S Options (see Ordering Information) Output Current Thermal Design Performance Level Packaging Output Voltage Input Voltage Product Family The first 12 characters comprise the base part number and the last 3 characters indicate available options. Model Number Input Voltage NQ12009SMA16xyz NQ12010SMA16xyz NQ12012SMA16xyz NQ12015SMA16xyz NQ12018SMA16xyz NQ12020SMA16xyz NQ12025SMA16xyz NQ12033SMA16xyz NQ12050SMA16xyz NQ12T50SMA16xyz * 9.6 - 14.4 V 9.6 - 14.4 V 9.6 - 14.4 V 9.6 - 14.4 V 9.6 - 14.4 V 9.6 - 14.4 V 9.6 - 14.4 V 9.6 - 14.4 V 9.6 - 14.4 V 9.6 - 14.4 V Output Max Output Voltage Current 0.9 V 16 A 1.0 V 16 A 1.2 V 16 A 1.5 V 16 A 1.8 V 16 A 2.0 V 16 A 2.5 V 16 A 3.3 V 16 A 5.0 V 16 A 0.9-5.0 V 16 A * Represents the wide trim unit. Detailed specifications for fixed Application Notes output voltage modules are located in a separate datasheet locat- A variety of application notes and technical white papers can be downloaded in pdf format at www.synqor.com. ed on the SynQor website. The following option choices must be included in place of the x y z spaces in the model numbers listed above. Options Description: x y z Contact SynQor for further information: Phone: Toll Free: Fax: E-mail: Web: Address: Product # NQ12T50SMA16 978-849-0600 888-567-9596 978-849-0602 [email protected] www.synqor.com 155 Swanson Road Boxborough, MA 01719 Phone 1-888-567-9596 Enable Logic Pin Style Feature Set P - Positive/Open S - SMT S - Standard Warranty SynQor offers a three (3) year limited warranty. Complete warranty information is listed on our web site or is available upon request from SynQor. Information furnished by SynQor is believed to be accurate and reliable. However, no responsibility is assumed by SynQor for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of SynQor. Doc.# 005-2NS12TE Rev. A 5/28/04 Page 15