20 Watt NT Single Series DC/DC Converters Features ! Fully Self Contained, No External Parts Required for Operation ! Low and Specified Input/Output Capacitance ! Efficiencies to 85% ! Overcurrent Protected and Thermal Shutdown Circuitry for Long, Reliable Operation ! Five-sided, Shielded, Low Thermal Gradient Copper Case ! 5 Year Warranty ! Water Washable Case Design Description Selection Chart These 20 Watt NT converters are ideal for battery operated industrial, medical control and remote data collection systems. They have achieved an exceptionally low input/output capacitance (290 pF) that is half that of comparable models. This low capacitance contributes to their exceptional input/ output isolation. Model 12S3.4000NT 12S5.4000NT 12S12.1700NT 12S15.1400NT 24S3.4000NT 24S5.4000NT 24S12.1700NT 24S15.1400NT 48S3.4000NT 48S5.4000NT 48S12.1700NT 48S15.1400NT Complete overload protection with independent pulse-bypulse current limiting and an overtemperature shutdown circuit ensure zero-failure rate operation. Each converter is encased in a five-sided, shielded and sealed water washable case. Input Range VDC Min Max 9 18 9 18 9 18 9 18 18 36 18 36 18 36 18 36 36 72 36 72 36 72 36 72 Output VDC Output mA 3.33 5 12 15 3.33 5 12 15 3.33 5 12 15 4000 4000 1700 1400 4000 4000 1700 1400 4000 4000 1700 1400 20 Watt NT Single Series Block Diagram A 2401 Stanwell Drive • Concord, California 94520 • Ph: 925/687-4411 or 800/542-3355 • Fax: 925/687-3333 • www.calex.com • Email: [email protected] 1 3/2001 20 Watt NT Single Series DC/DC Converters Input Parameters* Model 12S3.4000NT Voltage Range Reflected Ripple (2) Input Current Full Load No Load Efficiency Switching Frequency Maximum Input Overvoltage, 100ms Maximum Turn-on Time, 1% Output Error Recommended Fuse 12S5.4000NT 12S12.1700NT 12S15.1400NT 18 36 35 TYP TYP TYP TYP 15 10 1.46 16 76 2.12 16 79 2.15 16 79 2.21 16 79 TYP MAX mA P-P 0.70 10 80 1.01 10 83 mA RMS A mA % kHz 24 45 TYP Units VDC 220 24S12.1700NT 24S15.1400NT Reflected Ripple (2) 24S5.4000NT 9 18 40 Model Voltage Range 24S3.4000NT MIN MAX TYP VDC 10 ms (3) AMPS 48S3.4000NT 48S5.4000NT 48S12.1700NT 48S15.1400NT Units MIN MAX TYP 18 36 35 36 72 20 mA P-P TYP 10 6 mA RMS Input Current Full Load No Load Efficiency TYP TYP TYP Switching Frequency Maximum Input Overvoltage, 100ms Maximum Turn-on Time, 1% Output Error Recommended Fuse TYP 1.00 10 85 1.02 10 86 0.35 8 80 0.50 8 83 VDC 0.51 8 84 0.51 8 85 220 MAX kHz 45 85 TYP A mA % VDC 10 ms (3) AMPS Output Parameters* Model Output Voltage 12S3.4000NT 24S3.4000NT 48S3.4000NT 3.33 3.30 3.33 3.36 0.0 4.0 0.3 0.6 0.5 1.0 12S5.4000NT 24S5.4000NT 48S5.4000NT 5 4.95 5.00 5.05 0.0 4.0 0.2 0.4 Load Regulation 25% Max-Max Load Line Regulation Vin = Min-Max VDC Short Term Stability (4) MIN TYP MAX MIN MAX TYP MAX TYP MAX TYP Long Term Stability TYP Transient Response (5) Dynamic Response (6) Input Ripple Rejection (7) TYP TYP TYP 50 100 300 Noise, 0-20MHz bw (2) RMS Noise, 0.01-1MHz TYP TYP TYP MAX 50 10 60 14 Output Voltage Accuracy Rated Load Range Temperature Coefficient A 12S15.1400NT 24S15.1400NT 48S15.1400NT 15 14.90 15.00 15.10 0.0 1.4 0.1 0.2 Units VDC VDC A % % %/24Hrs < 0.2 %/kHrs 300 300 350 µs mV peak dB 50 8 50 8 mV P-P mV RMS > 40 Short Circuit Protection to Common for all Outputs 50 150 ppm/°C Continuous, Current Limit and Thermal Protection NOTES * 12S12.1700NT 24S12.1700NT 48S12.1700NT 12 11.90 12.00 12.10 0.0 1.7 0.1 0.2 0.01 0.1 < 0.05 (2) All parameters measured at Tc=25°C, nominal input voltage and full rated load unless otherwise noted. Refer to the CALEX Application Notes for the definition of terms, measurement circuits and other information. Noise is measured per CALEX Application Notes. Measurement bandwidth is 0-20 MHz for peak-peak measurements, 10 kHz to 1 MHz for RMS measurements. Output noise is measured with a 0.01µF ceramic in parallel with a 1µF/35V Tantalum capacitor located 1" away from the converter to simulate 2401 Stanwell Drive • Concord, California 94520 • Ph: 925/687-4411 or 800/542-3355 • Fax: 925/687-3333 • www.calex.com • Email: [email protected] 2 3/2001 20 Watt NT Single Series DC/DC Converters General Specifications* All Models ON/OFF Function ON Logic Level or Leave Pin Open OFF Logic Level or Tie Pin to -Input Open Circuit Voltage Input Resistance Converter Idle Current ON/OFF Pin Low 12S Models 24S and 48S Models Units MIN >1.6 VDC MAX <0.7 VDC TYP TYP 2.5 20 VDC kohms TYP TYP 13 14 mA mA MIN MIN 700 1544 VDC TYP 290 pF Isolation (8) Isolation Voltage Input to Output 12S, 24S Input to Output 48S 10µA Leakage Input to Output Capacitance Output Trim Function Trim Range Input Resistance Open Circuit Voltage Environmental Case Operating Range No Derating Case Functional Range (9) Storage Range Thermal Shutdown Case Temperature Thermal Impedance (10) General Unit Weight Chassis Mounting Kit BOTTOM VIEW SIDE VIEW Mechanical tolerances unless otherwise noted: X.XX dimensions: ±0.020 inches X.XXX dimensions: ±0.005 inches MIN MIN TYP ±5 10 2.5 % kohms VDC MIN MAX MIN MAX MIN MAX -40 90 -55 100 -55 105 TYP 105 °C TYP 9.5 °C/Watt TYP 2.3 Pin 1 2 3 4 5 6 °C °C Function ON/OFF -INPUT +INPUT +OUTPUT CMN TRIM °C oz MS8 NOTES (cont.) your PCB’s standard decoupling. Input reflected ripple is measured into a 10µH source impedance. (3) To determine the correct fuse size, see CALEX Application Notes. (4) Short term stability is specified after a 30 minute warmup at full load, constant line and recording the drift over a 24 hour period. (5) The transient response is specified as the time required to settle from a 50 to 75 % step load change (rise time of step = 2 µSec) to a 1% error band. (6) Dynamic response is the peak overshoot voltage during the transient response time as defined in note 5 above. (7) The input ripple rejection is specified for DC to 120 Hz ripple with a modulation amplitude of 1% of Vin. (8) The Case is tied to the -IN pin. (9) The functional temperature range is intended to give an additional data point for use in evaluating this power supply. At the low functional temperature the power supply will function with no side effects, however, sustained operation at the high functional temperature will reduce expected operational life. The data sheet specifications are not guaranteed over the functional temperature range. (10) The case thermal impedance is specified as the case temperature rise over ambient per package watt dissipated. (11) Specifications subject to change without notice. A Applications Information General Information The 20 Watt NT Single series is also mindful of battery operation for industrial, medical control and remote data collection applications. The remote ON/OFF pin places the converter in a very low power mode that draws typically less than 3 mA from the input source. Full overload protection is provided by independent pulse-bypulse current limiting and an over-temperature shutdown circuit. These protection features assure you that our 20 Watt single will provide zero failure rate operation. A fully five-sided shielded, sealed, water washable case is standard along with specified operation over the full industrial temperature range of -40 to +90°C. 2401 Stanwell Drive • Concord, California 94520 • Ph: 925/687-4411 or 800/542-3355 • Fax: 925/687-3333 • www.calex.com • Email: [email protected] 3 3/2001 20 Watt NT Single Series DC/DC Converters General Operation For applications that require remote sensing, the circuit shown in Figure 3 may be used. This circuit can adjust for up to 0.25 Volts drop in a 5 Volt output. This is equivalent to 0.06 ohms at 4 Amps. Figure 1 shows the recommended connections for the 20 Watt NT Single DC/DC converter. A fuse is recommended to protect the input circuit and should not be omitted. D1, D2 - Overvoltage clamp is optional, see text Figure 1. Standard connections for the 20 Watt NT Single: The ON/OFF and TRIM pins can be left floating if they are not used. The input fuse should not be omitted. The overvoltage diodes may be added to the circuit directly at the converter to provide transient protection to your circuit. C1 = 0.01µF, 100V, CER D1 = 1N4448 Q1 = 2N3906 IC1 = TL431CLP R1 = 470 OHM, 1/4W, 5% R2 = 1.0K, 1/4W, 5% R3 = 2.4K, 1/4W, 5% R4, R5 = 4.99K, 1/4W, 5% The ON/OFF and +5 TRIM pins may be left floating if they are not used. No external capacitance on either the input or outputs is required for normal operation, in fact, it can degrade the converter’s performance. See our application note “Understanding DC/DC Converters Output Impedance” and the low noise circuits later in this data sheet for more information. The usual 0.1 to 0.001 µF bypasses may be used around your PCB as required without harm. Figure 3. This remote sensing circuit can be used to automatically adjust for voltage drops in your system’s wiring. Extremely low ESR capacitors (< 0.5 ohms) should not be used at the input as this will cause peaking of the input filter’s transfer function and actually degrade the filter’s performance. Applying the Output The output is simply connected to your application circuit and away you go. If extra low output noise is required in your application the circuit shown in Figure 2 may be used to reduce the output noise to below 10 mV P-P. Figure 4. The output can be trimmed by either a trimpot or fixed resistors. If fixed resistors are used their values may range from 0 to infinite ohms. The trimpot should be 10 kohms nominal for 3.3 and 5 Volt units and 20 kohms for 12 and 15 Volt outputs. A Non Standard Output Voltages The trim may be used to adjust a +5 output unit up to 5.2 Volts for ECL applications. L1 = 2µH C1, C3 = 0.01µF, CERAMIC C2 = 10µF/35V, TANTALUM +12 Volt units will trim around a range of approximately +9.6 to +12.6 Volts. +15 Volt units will trim around a range of approximately +12 to +15.75 Volts. Figure 2. For very low noise applications the circuits shown above can be used. The input current ripple will be reduced approximately 30 dB of the original value while the output noise will be reduced to typically below 10 mV P-P. Maximum power from the module is limited to the specified non-trimmed maximum (Typical Output Voltage x Maximum Rated Load = Maximum Power). Trimming the output up reduces the output current proportionally to keep the maximum power constant. Output current is not increased over the Rated Maximum when trimming the output voltage down. The trim pin may be used to adjust the outputs by up to +5 % from the nominal factory setting to account for system wiring voltage drops. Figure 4 shows the proper connections to use the trim pin. If output trimming is not desired the trim pin may be safely left floating. See our application note on remote sense and trim functions for more information. 2401 Stanwell Drive • Concord, California 94520 • Ph: 925/687-4411 or 800/542-3355 • Fax: 925/687-3333 • www.calex.com • Email: [email protected] 4 3/2001 20 Watt NT Single Series DC/DC Converters Grounding Temperature Derating The input and output sections are fully floating from each other. They may be operated floating or with a common ground. If the input and output sections are connected either directly at the converter or at some remote location from the converter it is suggested that a 1 to 10µF, 0.5 to 5 ohm ESR capacitor bypass be used directly at the converter output pins. This capacitor prevents any common mode switching currents from showing up at the converter’s output as normal mode output noise. Do not use the lowest ESR, biggest value capacitor that you can find! This can only lead to reduced system performance or oscillation. See our application note “Understanding Output Impedance For Optimum Decoupling” for more information. The NT Single Series can operate up to 90°C case temperature without derating. Case temperature may be roughly calculated from ambient by knowing that the NT Singles case temperature rise is approximately 9.5°C per package watt dissipated. For example: If a 24 Volt input converter was delivering 15 Watts at 24 Volts input, at what ambient could it expect to run with no moving air and no extra heat sinking? Efficiency is approximately 86%. This leads to an input power of about 17.4 Watts. The case temperature rise would be 2.4 Watts x 9.5 = 22.8°C. This number is subtracted from the maximum case temperature of 90°C to get 67°C. This is a rough approximation to the maximum ambient temperature. Because of the difficulty of defining ambient temperature and the possibility that the load’s dissipation may actually increase the local ambient temperature significantly or that convection cooling is suppressed by physical placement of the module, these calculations should be verified by actual measurement of operating temperature and your circuit’s exact efficiency (efficiency depends on both line input and load value) before committing to a production design. Case Grounding The case serves not only as a heat sink but also as an EMI shield. The 0.02 inch thick copper provides >25 dB of absorption loss to both electromagnetic and electric fields at 220 kHz, while at the same time providing about 30% better heat sinking than competitive 0.01 inch thick steel cases. The case shield is tied to the -input pin. This connection is shown on the block diagram. The case is floating from the input, coupled only by the 290 pF of isolation capacitance. Remote ON/OFF Pin Operation The remote ON/OFF pin may be left floating if this function is not used. The equivalent input circuit for the ON/OFF pin is shown in Figure 5. The best way to drive this pin is with an open collector/drain or relay contact. See our application note titled “Understanding the Remote ON/OFF Function” for more information about using the remote ON/OFF pin. When the ON/OFF pin is pulled low with respect to the Input, the converter is placed in a low power drain state. When the ON/OFF pin is released the converter fully powers up in typically 10 milliseconds. The ON/OFF pin turns the converter off while keeping the input bulk capacitor fully charged. This prevents the large inrush current spike that occurs when the +input pin is opened and closed. A Figure 5. The simplified schematic of the NT Single Series ON/OFF pin. The input impedance is approximately 20 kohms. The maximum open circuit voltage is approximately 2.5 Volts. By leaving this pin floating the converter will be in the ON state. When the pin is pulled below 0.7 Volts the converter is placed in the power down or OFF state. See our application note on the remote ON/OFF function for more information. 2401 Stanwell Drive • Concord, California 94520 • Ph: 925/687-4411 or 800/542-3355 • Fax: 925/687-3333 • www.calex.com • Email: [email protected] 5 3/2001 20 Watt NT Single Series DC/DC Converters Typical Performance (Tc=25°C, Vin=Nom VDC, Rated Load). 12 VOLT EFFICIENCY Vs. LOAD 12 VOLT EFFICIENCY Vs. LINE INPUT VOLTAGE 85 4 LINE = 9VDC INPUT CURRENT (AMPS) 50% FULL LOAD 80 EFFICIENCY(%) 80 LINE = 12VDC 75 LINE = 18VDC 70 100% FULL LOAD 75 70 65 10 20 30 40 50 60 70 80 90 100 50% LOAD 1 10 11 12 13 14 15 16 17 18 0 24 VOLT EFFICIENCY Vs. LOAD 24 VOLT EFFICIENCY Vs. LINE INPUT VOLTAGE 100% FULL LOAD EFFICIENCY(%) 80 LINE = 24VDC 50% FULL LOAD 80 75 LINE = 36VDC 65 70 10 20 30 40 50 60 70 80 90 100 20 22 LOAD (%) 48 VOLT EFFICIENCY Vs. LOAD 85 85 24 26 28 30 32 34 EFFICIENCY(%) LINE = 36VDC 75 70 LINE = 48VDC 65 LINE = 72VDC 10 20 30 40 50 60 5 10 70 80 90 100 15 20 25 30 35 40 48 VOLT INPUT CURRENT Vs. LINE INPUT VOLTAGE 1.0 80 75 50% FULL LOAD 70 0.8 0.6 100% LOAD 0.4 50% LOAD 0.2 0.0 36 40 LOAD (%) 44 48 52 56 60 64 68 72 0 10 20 LINE INPUT(VOLTS) OUTPUT VOLTAGE Vs. OUTPUT LOAD 120 NORMALIZED OUTPUT (%) .1 .01 30 40 50 60 70 80 LINE INPUT (VOLTS) OUTPUT IMPEDANCE Vs. FREQUENCY 1 OUTPUT IMPEDANCE (OHMS) 50% LOAD LINE INPUT (VOLTS) 60 0 18 0.5 0 65 60 16 100% LOAD 36 100% FULL LOAD 80 14 1.0 48 VOLT EFFICIENCY Vs. LINE INPUT VOLTAGE 90 12 1.5 LINE INPUT(VOLTS) 90 10 0.0 18 INPUT CURRENT (AMPS) 0 8 24 VOLT INPUT CURRENT Vs. LINE INPUT VOLTAGE 85 70 6 2.0 LINE = 18VDC 75 4 LINE INPUT (VOLTS) 90 85 2 LINE INPUT(VOLTS) 90 EFFICIENCY (%) 2 0 9 LOAD (%) EFFICIENCY (%) 100% LOAD 3 65 0 INPUT CURRENT (AMPS) EFFICIENCY (%) 12 VOLT INPUT CURRENT Vs. LINE INPUT VOLTAGE 85 A 100 80 60 CURRENT LIMIT MODE -> 40 20 0 10 100 1000 10000 100000 1000000 0 FREQUENCY (Hz) 20 40 60 80 100 120 140 OUTPUT LOAD (%) NOTE ON USING THE CURVES These curves were generated for 12 volt output models. To use for other models, adjust the efficiency values as shown below: 3.3 volt models ..... Subtract approximately 4% 5.0 volt models ..... Subtract approximately 2% 15.0 volt models ... Add approximately 1% 2401 Stanwell Drive • Concord, California 94520 • Ph: 925/687-4411 or 800/542-3355 • Fax: 925/687-3333 • www.calex.com • Email: [email protected] 6 3/2001