Technical S pecification PQ24033QGL25 24V in 3.3Vout 25Amp 2000Vdc Quar ter-brick Input Output Current Isolation DC/DC Conver ter The PQ240 33QGL25 PowerQor™ Giga quarter-brick converter is a next-generation, board-mountable, isolated, fixed switching frequency DC/DC converter that uses synchronous rectification to achieve extremely high conversion efficiency. The power dissipated by the converter is so low that a heatsink is not required, which saves cost, weight, height, and application effort. All of the power and control components are mounted to the multi-layer PCB substrate with high-yield surface mount technology. The QGL series employs a very low profile to accommodate tight spacing requirements. RoHS 5/6 compliant (see page 12). PQ24033QGL25 Module Operational Features • Ultra-high efficiency, 87% at full rated load current • Delivers up to 25 amps of output current with minimal derating - no heatsink required • Wide input voltage range: 18V – 36V meets or exceeds all 24V bus standards • Fixed frequency switching provides predictable EMI performance • No minimum load requirement means no preload resistors required Mechanical Features • Industry standard quarter-brick pin-out configuration • Industry standard size: 1.45” x 2.3” (36.8x58.4mm) • Total height less than 0.335” (8.5mm), permits better airflow and smaller card pitch, meets NTT reqs. • Total weight: 1.2 oz. (34 grams) • Flanged pins designed to permit surface mount soldering (avoid wave solder) using FPiP technique Contr ol Features • On/Off control referenced to input side (positive and negative logic options are available) • Remote sense for the output voltage compensates for output distribution drops • Output voltage trim permits custom voltages and voltage margining Product # PQ24033QGL25 Phone 1-888-567-9596 www.synqor.com Pr otection Features • Input under-voltage lockout disables converter at low input voltage conditions • Output current limit and short circuit protection protects converter and load from permanent damage and consequent hazardous conditions • Active back bias limit prevents damage to converter from external load induced pre-bias • Output over-voltage protection protects load from damaging voltages • Thermal shutdown protects converter from abnormal environmental conditions Safety Features • 2000V, 30 MΩ input-to-output isolation provides input/output ground separation • UL/cUL 60950 recognized (US & Canada), basic insulation rating • 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 • NEBS and ETSI compliant Doc.# 005-2QL233D Rev. A 06/23/05 Page 1 Input: Output: Current: Package: Technical Specification MECHANICAL DIAGRAM 18-36 V 3.3 V 25 A Quarter-brick 0.600 0.450 (15.24) 2.30 (58.4) 0.300 2.00 (50.8) 0.150 (11.43) (7.62) (3.81) 0.14 (3.6) 8 7 6 5 4 1 0.600 2 (15.24) Top View 3 1.45 (36.8) 0.43 0.300 (10.9) (7.62) Side View Total Height 0.320 +0.015 (8.13 +0.38) Lowest Component Load Board Flanged Pin See Note 10 0.145 Bottom side Clearance (3.68) See Note 3 See Note 9 0.017 +0.015 (0.43 +0.38) NOTES PIN DESIGNATIONS 1) Pins 1-3, 5-7 are 0.040” (1.02mm) diameter with 0.080” (2.03 mm) diameter standoff shoulders. 2) Pins 4 and 8 are 0.062” (1.57 mm) diameter with 0.100” (2.54 mm) diameter standoff shoulders. 3) Other pin extension lengths available. Recommended pin length is 0.03” (0.76mm) greater than the PCB thickness. 4) All Pins: Material - Copper Alloy Finish - Tin/Lead over Nickel plate 5) Undimensioned components are shown for visual reference only. 6) All dimensions in inches (mm) Tolerances: x.xx +0.02 in. (x.x +0.5mm) x.xxx +0.010 in. (x.xx +0.25mm) 7) Weight: 1.2 oz. (34 g) typical 8) Workmanship: Meets or exceeds IPC-A-610C Class II 9) UL/TUV standards require a clearance greater than 0.04” (1.02mm) between input and output for Basic insulation. This issue should be considered if any copper traces are on the top side of the user’s board. Note that the ferrite cores are considered part of the input/primary circuit. 10) The flanged pins are designed to permit surface mount soldering (avoiding the wave soldering process) through the use of the flanged pin-in-paste technique. Product # PQ24033QGL25 Phone 1-888-567-9596 Pin No. Name Function 1 Vin(+) Positive input voltage 2 ON/OFF TTL input to turn converter on and off, referenced to Vin(-), with internal pull up. 3 Vin(-) Negative input voltage 4 Vout(-) Negative output voltage 5 SENSE(-) Negative remote sense1 6 TRIM Output voltage trim2 7 SENSE(+) Positive remote sense3 8 Vout(+) Positive output voltage Notes: 1. SENSE(-) may be connected to Vout(-) or left open. 2. Leave TRIM pin open for nominal output voltage. 3. SENSE(+) may be connected to Vout(+) or left open. www.synqor.com Doc.# 005-2QL233D Rev. A 06/23/05 Page 2 Input: Output: Current: Package: Technical Specification 18-36 V 3.3 V 25 A Quarter-brick PQ24033QGL25 ELECTRICAL CHARACTERISTICS TA=25°C, airflow rate=300 LFM, Vin=24Vdc unless otherwise noted; full operating temperature range is -40°C to +100°C ambient temperature with appropriate power derating. Specifications subject to change without notice. Parameter Min. Typ. Max. Units 50 40 50 2000 100 125 18 V V V V °C °C V Notes & Conditions ABSOLUTE MAXIMUM RATINGS Input Voltage Non-Operating Operating Operating Transient Protection Isolation Voltage (input to output) 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 Voltage Hysteresis Maximum Input Current No-Load Input Current Disabled Input Current Inrush Current Transient Rating Input Reflected Ripple Current Input Terminal Ripple Current Recommended Input Fuse Input Filter Component Values (L\C) Recommended External Input Capacitance OUTPUT CHARACTERISTICS Output Voltage Set Point Output Voltage Regulation Over Line Over Load Over Temperature Total Output Voltage Range Output Voltage Ripple and Noise1 Peak-to-Peak RMS Operating Output Current Range Output DC Current-Limit Inception Output DC Current-Limit Shutdown Voltage Back-Drive Current Limit while Enabled Back-Drive Current Limit while Disabled Maximum Output Capacitance -40 -55 -2 18 24 36 V 15.5 14.0 0.5 16.5 15.0 1.5 17.5 16.0 2.5 5.5 140 3 0.03 V V V A mA mA A 2s mA mA A µH\µF µF 100 1.6 20 280 1.0\11 100 3.267 3.21 0 26 0.5 0 DYNAMIC CHARACTERISTICS Input Voltage Ripple Rejection Output Voltage During Load Current Transient For a Step Change in Output Current (0.16A/µs) For a Step Change in Output Current (0.4A/µs) Settling Time Turn-On Transient Turn-On Time Start-Up Inhibit Time Output Voltage Overshoot EFFICIENCY 100% Load 50% Load 1 180 3.300 20 3.333 +0.05 \ 2 +0.15 \ 5 +0.05 \ 2 +0.15 \ 5 +17 +50 3.39 30 5 28.5 1.7 1.0 10 60 10 25 30 1.5 20 20,000 P-P thru 10µH inductor; Figures 13 & 15 RMS; Figures 13 & 14 fast blow external fuse recommended internal values, see Figure E Typical ESR 0.1-0.2Ω, see Figure 13 V %\mV %\mV mV V mV mV A A V A mA µF over sample, line, load, temperature & life 20MHz bandwidth; Fig. 13 & 16 Full Load, see Figures 13 & 16 Full Load, see Figures 13 & 16 Subject to thermal derating; Figures 5-8 Output Voltage 10% Low; Figure 17 Negative current drawn from output Negative current drawn from output 3.3Vout at 25A Resistive Load dB 120 Hz; Fig. 20 160 160 500 mV mV µs 50% to 75% to 50% Iout max; Figure 11 50% to 75% to 50% Iout max; Figure 12 to within 1% Vout nom ms ms % Full load, Vout=90% nom.; Figures 9 & 10 -40°C to +125°C; Figure F 10,000 µF load capacitance, Iout = 0A % % Figures 1 - 4 Figures 1 - 4 °C °C °C Package rated to 150°C UL rated max operating temp 130°C See Figures 5 - 8 for derating curves 12 200 0 TEMPERATURE LIMITS FOR POWER DERATING CURVES Semiconductor Junction Temperature Board Temperature Transformer Temperature Isolation Voltage (dielectric strength) Isolation Resistance Isolation Capacitance2 100% Load, 18 Vin 55 14 240 87 90.5 ISOLATION CHARACTERISTICS continuous continuous < 10µs, 1% duty cycle Basic insulation, Pollution Degree 2 125 125 125 2000 30 470 V MΩ pF Note 1: For applications requiring reduced output voltage ripple and noise, consult SynQor applications support (e-mail: [email protected]) Note 2: Higher values of isolation capacitance can be added external to the module. Product # PQ24033QGL25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QL233D Rev. A 06/23/05 Page 3 Input: Output: Current: Package: Technical Specification 18-36 V 3.3 V 25 A Quarter-brick ELECTRICAL CHARACTERISTICS (Continued) Parameter P FEATURE CHARACTERISTICS Regulation Stage Switching Frequency Isolation Stage Switching Frequency ON/OFF Control (Option P) Off-State Voltage On-State Voltage ON/OFF Control (Option N) Off-State Voltage On-State Voltage ON/OFF Control (Either Option) Pull-Up Voltage Pull-Up Resistance Output Voltage Trim Range1 Output Voltage Remote Sense Range Output Over-Voltage Protection Over-Temperature Shutdown Over-Temperature Shutdown Restart Hysteresis Load Current Scale Factor Min. Typ. Max. Units 180 180 200 200 220 220 kHz kHz -2 2.4 0.8 18 V V 2.4 -2 18 0.8 V V 9.6 V kΩ % % % °C °C -20 Vin/3 33 117 RELIABILITY CHARACTERISTICS Calculated MTBF (Telcordia) Calculated MTBF (MIL-217) Field Demonstrated MTBF 122 125 10 643 +10 +10 127 Notes & Conditions Figures A, B Measured across Pins 8 & 4; Figure C Measured across Pins 8 & 4 Over full temp range; % of nominal Vout Average PCB Temperature See App Note: Output Load Current Calc. 10 Hrs. TR-NWT-000332; 80% load,300LFM, 40oC Ta 106 Hrs. MIL-HDBK-217F; 80% load, 300LFM, 40oC Ta 106 Hrs. see website for latest values 6 2.21 1.43 1. Trim-up range may be limited when Vin is below 20V and Iout is simultaneously above 20A. 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 File # E194341, Basic insulation & pollution degree 2 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, 2 minutes on and 6 hours off 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 Logic Sense, Pin Length 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 #s 5,999,417; 6,222,742 B1; 6,594,159 B2; 6,545,890 B2. Product # PQ24033QGL25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QL233D Rev. A 06/23/05 Page 4 Input: Output: Current: Package: Technical Specification 95 94 90 93 18-36 V 3.3 V 25 A Quarter-brick 92 Efficiency (%) Efficiency (%) 85 80 75 70 91 90 89 88 18Vin 25 C 24Vin 65 40 C 87 55 C 36Vin 86 60 0 5 10 15 20 0 25 100 200 300 400 500 Air Flow (LFM) Load Current (A) Figure 1: Efficiency at nominal output voltage vs. load current for minimum, nominal, and maximum input voltage at 25°C. Figure 2: Efficiency at nominal output voltage and 60% rated power vs. airflow rate for ambient air temperatures of 25°C, 40°C, and 55°C (nominal input voltage). 14 7.0 12 6.5 Power Dissipation (W) Power Dissipation (W) 6.0 10 8 6 4 5.5 5.0 4.5 4.0 25 C 18Vin 2 24Vin 40 C 3.5 55 C 36Vin 3.0 0 0 5 10 15 20 0 25 100 200 300 400 500 Air Flow (LFM) Load Current (A) Figure 3: Power dissipation at nominal output voltage vs. load current for minimum, nominal, and maximum input voltage at 25°C. Figure 4: Power dissipation at nominal output voltage and 60% rated power vs. airflow rate for ambient air temperatures of 25°C, 40°C, and 55°C (nominal input voltage). 25 Iout (A) 20 15 10 400 LFM (2.0 m/s) 5 300 LFM (1.5 m/s) 200 LFM (1.0 m/s) 100 LFM (0.5 m/s) Semiconductor junction temperature is within 1°C of surface temperature 0 0 25 40 55 70 85 Ambient Air Temperature (ºC) Figure 5: Maximum output power derating curves vs. ambient air temperature for airflow rates of 100 LFM through 400 LFM with air flowing from pin 1 to pin 3 (nominal input voltage). Product # PQ24033QGL25 Phone 1-888-567-9596 Figure 6: Thermal plot of converter at 23.5 amp load current with 55°C air flowing at the rate of 200 LFM. Air is flowing across the converter from pin 1 to pin 3 (nominal input voltage). www.synqor.com Doc.# 005-2QL233D Rev. A 06/23/05 Page 5 Input: Output: Current: Package: Technical Specification 18-36 V 3.3 V 25 A Quarter-brick 25 Iout (A) 20 15 10 400 LFM (2.0 m/s) 5 300 LFM (1.5 m/s) 200 LFM (1.0 m/s) 100 LFM (0.5 m/s) Semiconductor junction temperature is within 1°C of surface temperature 0 0 25 40 55 70 85 Ambient Air Temperature (ºC) Figure 7: Maximum output power-derating curves vs. ambient air temperature for airflow rates of 100 LFM through 400 LFM with air flowing from input to output (nominal input voltage). Figure 8: Thermal plot of converter at 23 amp load current with 55°C air flowing at the rate of 200 LFM. Air is flowing across the converter from input to output (nominal input voltage). Figure 9: Turn-on transient at full load (5 ms/div). Input voltage preapplied. Ch 1: Vout (1V/div). Ch 2: ON/OFF input (5V/div) Figure 10: Turn-on transient at zero load (5 ms/div). Ch 1: Vout (1V/div). Ch 2: ON/OFF input (5V/div). Figure 11: Output voltage response to step-change in load current (50%-75%50%) of Iout(max): dI/dt = 0.16A/µs. Load cap: 10µF, 100 mΩ ESR tantalum cap and 1µF ceramic cap. Ch 1: Vout (500mV/div), Ch 2: Iout (10A/div). Figure 12: Output voltage response to step-change in load current (50%75%-50%) of Iout(max): dI/dt = 0.4A/µs. Load cap: 470µF, 30 mΩ ESR tantalum cap and 1µF ceramic cap. Ch 1: Vout (500mV/div), Ch 2: Iout (10A/div). Product # PQ24033QGL25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QL233D Rev. A 06/23/05 Page 6 Input: Output: Current: Package: Technical Specification 18-36 V 3.3 V 25 A Quarter-brick See Fig. 15 10 µH See Fig. 14 source impedance See Fig. 16 iS iC VSOURCE DC/DC Converter VOUT 1 µF 47 µF, ≅1Ω ESR 10 µF, ceramic 100mΩ ESR capacitor tantalum capacitor electrolytic capacitor Figure 13: Test set-up diagram showing measurement points for Input Terminal Ripple Current (Figure 14), Input Reflected Ripple Current (Figure 15) and Output Voltage Ripple (Figure 16). Figure 14: Input Terminal Ripple Current, ic, at full rated output current and nominal input voltage with 10µ H source impedance and 47µF electrolytic capacitor (500 mA/div). See Figure 13. Figure 15: Input reflected ripple current, is, through a 10 µ H source inductor at nominal input voltage and rated load current (10 mA/div). See Figure 13. Figure 16: Output voltage ripple at nominal input voltage and rated load current (20 mV/div). Load capacitance: 1µF ceramic capacitor and 10µF tantalum capacitor. Bandwidth: 20 MHz. See Figure 13. 4.0 3.5 Output Voltage (V) 3.0 2.5 2.0 1.5 1.0 18 V 24 V 0.5 36 V 0.0 0 5 10 15 20 25 30 35 Load Current (A) Figure 17: Output voltage vs. load current showing typical current limit curves and converter shutdown points. Product # PQ24033QGL25 Phone 1-888-567-9596 Figure 18: Load current (20A/div) as a function of time when the converter attempts to turn on into a 1 mΩ short circuit. Top trace (2.5ms/div) is an expansion of the on-time portion of the bottom trace. www.synqor.com Doc.# 005-2QL233D Rev. A 06/23/05 Page 7 Input: Output: Current: Package: Technical Specification 0.1 18-36 V 3.3 V 25 A Quarter-brick -20 Forward Transmission (dB) Output Impedance (Ù) -30 0.01 0.001 18 Vin -40 -50 -60 -70 -80 18 Vin 24 Vin 24 Vin -90 36 Vin 36 Vin 0.0001 -100 10 100 1,000 10,000 100,000 10 100 Hz 1,000 10,000 100,000 Hz Figure 19: Magnitude of incremental output impedance (Zout = vout/iout) for minimum, nominal, and maximum input voltage at full rated power. Figure 20: Magnitude of incremental forward transmission (FT = vout/vin) for minimum, nominal, and maximum input voltage at full rated power. 100 0 -10 Input Impedance (Ù) Reverse Transmission (dB) -5 -15 -20 -25 -30 -35 -40 -45 10 1 18 Vin 18 Vin 24 Vin 24 Vin 36 Vin 36 Vin -50 0.1 10 100 1,000 10,000 100,000 10 Hz Phone 1-888-567-9596 1,000 10,000 100,000 Hz Figure 21: Magnitude of incremental reverse transmission (RT = iin/iout) for minimum, nominal, and maximum input voltage at full rated power. Product # PQ24033QGL25 100 Figure 22: Magnitude of incremental input impedance (Zin = vin/iin) for minimum, nominal, and maximum input voltage at full rated power. www.synqor.com Doc.# 005-2QL233D Rev. A 06/23/05 Page 8 Input: Output: Current: Package: Technical Specification 18-36 V 3.3 V 25 A Quarter-brick BASIC OPERATION AND FEATURES CONTROL FEATURES The PowerQor series converter uses a two-stage power conversion topology. The first stage is a buck-converter that keeps the output voltage constant over variations in line, load, and temperature. The second stage uses a transformer to provide the functions of input/output isolation and voltage step-down to achieve the low output voltage required. REMOTE ON/OFF (Pin 2): The ON/OFF input, Pin 2, permits the user to control when the converter is on or off. This input is referenced to the return terminal of the input bus, Vin(-). There are two versions of the converter that differ by the sense of the logic used for the ON/OFF input. Both the first stage and the second stage switch at a fixed frequency for predictable EMI performance. Rectification of the transformer’s output is accomplished with synchronous rectifiers. These devices, which are MOSFETs with a very low on-state resistance, dissipate far less energy than Schottky diodes. This is the primary reason that the PowerQor converter has such high efficiency, even at very low output voltages and very high output currents. Dissipation throughout the converter is so low that it does not require a heatsink for operation. Since a heatsink is not required, the PowerQor converter does not need a metal baseplate or potting material to help conduct the dissipated energy to the heatsink. The PowerQor converter can thus be built more simply and reliably using high yield surface mount techniques on a PCB substrate. The PowerQor series of half-brick and quarter-brick converters uses the industry standard footprint and pin-out configuration. In the positive logic version, the ON/OFF input is active high (meaning that a high turns the converter on). In the negative logic version, the ON/OFF signal is active low (meaning that a low turns the converter on). Figure A details five possible circuits for driving the ON/OFF pin. Figure B is a detailed look of the internal ON/OFF circuitry. REMOTE SENSE(+) (Pins 7 and 5): The SENSE(+) inputs correct for voltage drops along the conductors that connect the converter’s output pins to the load. Pin 7 should be connected to Vout(+) and Pin 5 should be connected to Vout(-) at the point on the board where regulation is desired. A remote connection at the load can adjust for a voltage drop only as large as that specified in this datasheet, that is [Vout(+) - Vout(-)] – [Vsense(+) - Vsense(-)] < Sense Range % x Vout Pins 7 and 5 must be connected for proper regulation of the output voltage. If these connections are not made, the converter will deliver an output voltage that is slightly lower than its specified value. Note: the output over-voltage protection circuit senses the voltage ON/OFF ON/OFF ON/OFF Vin(_) Vin(_) Vin(_) Remote Enable Circuit Negative Logic (Permanently Enabled) ON/OFF Positive Logic (Permanently Enabled) 5V Vin(+) 5V 100k ON/OFF 50k TTL TTL/ CMOS ON/OFF Vin(_) Vin(_) Open Collector Enable Circuit Vin(_) Direct Logic Drive Figure A: Various circuits for driving the ON/OFF pin. Product # PQ24033QGL25 100pF 50k Phone 1-888-567-9596 www.synqor.com Figure B: Internal ON/OFF pin circuitry Doc.# 005-2QL233D Rev. A 06/23/05 Page 9 Input: Output: Current: Package: Technical Specification across the output (pins 8 and 4) to determine when it should trigger, not the voltage across the converter’s sense leads (pins 7 and 5). Therefore, the resistive drop on the board should be small enough so that output OVP does not trigger, even during load transients. OUTPUT VOLTAGE TRIM (Pin 6): The TRIM input permits the user to adjust the output voltage across the sense leads up or down according to the trim range specifications. To decrease the output voltage, the user should connect a resistor between Pin 6 and Pin 5 (SENSE(-) input). For a desired decrease of the nominal output voltage, the value of the resistor should be Rtrim-down = - 10.22 (511 ∆%) (kΩ) where ∆% = Vnominal – Vdesired Vnominal x 100% To increase the output voltage, the user should connect a resistor between Pin 6 and Pin 7 (SENSE(+) input). For a desired increase of the nominal output voltage, the value of the resistor should be Rtrim-up = ( 5.11VOUT(100+∆%) _ 511 _ 1.225∆% ∆% 10.22 ) (kΩ) where VOUT = Nominal Output Voltage Figure C graphs the relationship between the trim resistor value and Rtrim-up and Rtrim-down, showing the total range the output voltage can be trimmed up or down. Trim Resistance (kOhms) 10,000 18-36 V 3.3 V 25 A Quarter-brick output over-voltage protection circuit is triggered. Trimming the output voltage too high may cause the over-voltage protection circuit to engage, particularly during transients. It is not necessary for the user to add capacitance at the Trim pin. The node is internally bypassed to eliminate noise. Total DC Variation of Vout: For the converter to meet its full specifications, the maximum variation of the DC value of Vout, due to both trimming and remote load voltage drops, should not be greater than that specified for the output voltage trim range. 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 Limit: The maximum current limit remains constant as the output voltage drops. However, once the impedance of the short across the output is small enough to make the output voltage drop below the specified Output DC Current-Limit Shutdown Voltage, the converter turns off. The converter then enters a “hiccup mode” where it repeatedly turns on and off at a 5 Hz (nominal) frequency with a 5% duty cycle until the short circuit condition is removed. This prevents excessive heating of the converter or the load board. Output Over-Voltage Limit: If the voltage across the output pins exceeds the Output Over-Voltage Protection threshold, the converter will immediately stop switching. This prevents damage to the load circuit due to 1) excessive series resistance in output current path from converter output pins to sense point, 2) a release of a short-circuit condition, or 3) a release of a current limit condition. Load capacitance determines exactly how high the output voltage will rise in response to these conditions. After 200 ms the converter will automatically restart. 1,000 100 10 1 0 2 4 6 8 10 % increase Vout 12 14 16 18 20 % decrease Vout Figure C: Trim Graph for 3.3Vout module Note: the TRIM feature does not affect the voltage at which the Product # PQ24033QGL25 Phone 1-888-567-9596 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 OverTemperature Shutdown value. It will allow the converter to turn on again when the temperature of the sensed location falls by the www.synqor.com Doc.# 005-2QL233D Rev. A 06/23/05 Page 10 Input: Output: Current: Package: Technical Specification 18-36 V 3.3 V 25 A Quarter-brick amount of the Over-Temperature Shutdown Restart Hysteresis value. APPLICATION CONSIDERATIONS Input System Instability: This condition can occur because any DC/DC converter appears incrementally as a negative resistance load. A detailed application note titled “Input System Instability” is available on the SynQor web site (www.synqor.com) which provides an understanding of why this instability arises, and shows the preferred solution for correcting it. Application Circuits: Figure D below provides a typical circuit diagram which details the input filtering and voltage trimming. Input Filtering and External Capacitance: Figure E below provides a diagram showing the internal input filter components. This filter dramatically reduces input terminal ripple current, which otherwise could exceed the rating of an external electrolytic input capacitor. The recommended external input capacitance is specified in the “Input Characterisitcs” section. More detailed information is available in the application note titled “EMI Characteristics” on the SynQor website. Vin(+) Vin External Input Filter Electrolytic Capacitor 100µF Vout(+) Vsense(+) ON/OFF Trim Vsense(_) Vin(_) Rtrim-up or Rtrim-down Cload Iload Vout(_) Figure D: Typical application circuit (negative logic unit, permanently enabled). L Vin(+) C Vin(_) Figure E: Internal Input Filter Diagram (component values listed on page 3). Product # PQ24033QGL25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QL233D Rev. A 06/23/05 Page 11 Input: Output: Current: Package: Technical Specification 18-36 V 3.3 V 25 A Quarter-brick Startup Inhibit Period: The Startup Inhibit Period ensures that the converter will remain off for approximately 200ms when it is shut down for any reason. When an output short is present, this generates a 5Hz "hiccup mode," which prevents the converter from overheating. In all, there are seven ways that the converter can be shut down, initiating a Startup Inhibit Period: At time t1, the unit is disabled by the ON/OFF pin, and it cannot be enabled again until the Startup Inhibit Period has elapsed. • Input Under-Voltage Lockout RoHS Compliance: The EU led RoHS (Restriction of Hazardous Substances) Directive bans the use of Lead, Cadmium, Hexavalent Chromium, Mercury, Polybrominated Biphenyls (PBB), and Polybrominated Diphenyl Ether (PBDE) in Electrical and Electronic Equipment. SynQor products are currently 5/6 RoHS compliant with lead being the exception. For additional information on please email [email protected]. • Input Over-Voltage Shutdown (not present in Quarter-brick) • Output Over-Voltage Protection • Over Temperature Shutdown • Current Limit • Short Circuit Protection When the ON/OFF pin goes high after t2, the Startup Inhibit Period has elapsed, and the output turns on within the typical Turn-On Time. • Turned off by the ON/OFF input Figure F shows three turn-on scenarios, where a Startup Inhibit Period is initiated at t0, t1, and t2: Before time t0, when the input voltage is below the UVL threshold, the unit is disabled by the Input Under-Voltage Lockout feature. When the input voltage rises above the UVL threshold, the Input Under-Voltage Lockout is released, and a Startup Inhibit Period is initiated. At the end of this delay, the ON/OFF pin is evaluated, and since it is active, the unit turns on. Vin Under-Voltage Lockout Turn-On Threshold ON/OFF (pos logic) ON OFF ON OFF ON 4ms (typical Vout turn on time) 200ms (typical start-up inhibit period) t1 t0 200ms 200ms t2 t Figure F: Startup Inhibit Period (turn-on time not to scale) Product # PQ24033QGL25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QL233D Rev. A 06/23/05 Page 12 Input: Output: Current: Package: Technical Specification 18-36 V 3.3 V 25 A Quarter-brick PART NUMBERING SYSTEM ORDERING INFORMATION The part numbering system for SynQor’s PowerQor 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. QGL series indicates units with low profile (0.33”, 8.5mm). PQ 24 033 Q G L 25 N K S Options (see Ordering Information) Output Current Thermal Design Model Number Input Voltage PQ24033QGL25xyz 18 - 36 V Performance Level Package Size Output Max Output Voltage Current 3.3 V 25 A Output Voltage Input Voltage Product Family The following option choices must be included in place of the x y z spaces in the model numbers listed above. The first 12 characters comprise the base part number and the last 3 characters indicate available options. Although there are no default values for enable logic and pin length, the most common options are negative logic and 0.145” pins. These part numbers are more likely to be readily available in stock for evaluation and prototype quantities. Options Description: x y z Enable Logic Pin Length Feature Set K - 0.110" P - Positive N - 0.145" S - Standard N - Negative R - 0.180" Y - 0.250" Application Notes A variety of application notes and technical white papers can be downloaded in pdf format at www.synqor.com. Contact SynQor for further information: Phone: Toll Free: Fax: E-mail: Web: Address: Product # PQ24033QGL25 978-849-0600 888-567-9596 978-849-0602 [email protected] www.synqor.com 155 Swanson Road Boxborough, MA 01719 USA Phone 1-888-567-9596 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. www.synqor.com Doc.# 005-2QL233D Rev. A 06/23/05 Page 13