20 Watt NT Dual 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 ! Five Year Warranty ! Water Washable Case Design Description Selection Chart Designed to save valuable PC board space, the 20 Watt NT Dual series is ideal for use in battery operated industrial, medical control and remote data collection systems. Each unit is completely filtered to reduce noise, has an exceptionally low input/output capacitance and provides efficiencies to 85%. Model Complete overload protection with independent pulse-bypulse current limiting and an overtemperature shutdown circuit ensure zero-failure rate operation. Their copper cases are five-sided, shielded and water washable. Input Range VDC Output VDC Output mA 1700 Min Max 12D5.1700NT 9 18 ±5 12D12.850NT 9 18 ±12 850 12D15.700NT 9 18 ±15 700 1700 24D5.1700NT 18 36 ±5 24D12.850NT 18 36 ±12 850 24D15.700NT 18 36 ±15 700 1700 48D5.1700NT 36 72 * ±5 48D12.850NT 36 72 * ±12 850 48D15.700NT 36 72 * ±15 700 * UL Recognition only applies up to 60 VDC 20 Watt NT Dual 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 eco: 010403-2 20 Watt NT Dual Series DC/DC Converters Input Parameters* Model 12D5.1700NT Reflected Ripple (1) MIN MAX TYP 12D12.850NT 9.0 18.0 350 Input Current No Load Full Load Efficiency TYP TYP TYP TYP 100 40 2170 78 Voltage Range Switching Frequency Maximum Input Overvoltage, 100 ms maximum Turn-on Time, 1% Output Error Recommended Fuse 40 1750 81 12D15.700NT 24D5.1700NT 40 2210 79 TYP 40 875 81 VDC mA P-P 40 40 1010 84 mA RMS 40 1030 85 45 TYP mA % VDC 6 ms (2) AMPS Reflected Ripple (1) MIN MAX TYP 48D12.850NT 36.0 72.0 * 90 Input Current No Load Full Load Efficiency TYP TYP TYP TYP 25 40 505 84 40 440 81 Units kHz 24 48D5.1700NT Switching Frequency Maximum Input Overvoltage, 100 ms maximum Turn-on Time, 1% Output Error Recommended Fuse 24D15.700NT 220 MAX Model Voltage Range 24D12.850NT 18.0 36.0 140 48D15.700NT Units VDC mA P-P mA RMS 40 520 84 mA % TYP 220 kHz MAX 85 VDC TYP 6 ms (2) AMPS * UL Recognition only applies up to 60 VDC Output Parameters* Model Output Voltage Cross Regulation (13) Line Regulation Vin = Min-Max VDC Short Term Stability (5) MIN TYP MAX TYP MAX MIN MAX TYP MAX TYP TYP MAX TYP Long Term Stability Transient Response (6) Dynamic Response (7) Input Ripple Rejection (8) TYP TYP TYP TYP Noise, 0-20MHz bw (1) RMS Noise, 0.01-1 MHz bw TYP TYP TYP MAX Output Voltage Accuracy Output Balance Plus to Minus Output, Full Load Rated Load Range Load Regulation (12) Temperature Coefficient Short Circuit Protection to Common for all Outputs 12D5.1700NT 24D5.1700NT 48D5.1700NT ±5 4.95 5.00 5.05 12D12.850NT 24D12.850NT 48D12.850NT ±12 11.90 12.00 12.10 < 0.5 1.0 0.0 0.85 0.1 0.6 1.0 < 0.2 0.8 < 0.05 0.0 1.7 0.3 0.7 2.5 < 0.1 0.8 < 0.2 100 120 > 40 100 70 50 15 50 10 50 150 A 12D15.700NT 24D15.700NT 48D15.700NT ±15 14.90 15.00 15.10 Units VDC VDC % 0.0 0.7 0.2 0.6 1.0 < 0.2 0.8 A % % % %/24Hrs Output never exceeds 1% 100 %/kHrs µs mV peak dB 50 10 mV P-P mV RMS ppm/°C Continuous, Current Limit and Thermal Protection 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 eco: 010403-2 20 Watt NT Dual 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 500 pF MIN MIN ±5 60 % kohms MIN MAX MIN Case Functional Range (10) MAX MIN Storage Range MAX Thermal Shutdown TYP Case Temperature Thermal Impedance (11) TYP -40 90 -50 100 -55 105 °C 105 °C 9.5 °C/Watt Isolation (3) Breakdown Voltage Input to Output 12D, 24D Input to Output 48D 10 µA Leakage Input to Output Capacitance Output Trim Function Trim Range Input Resistance BOTTOM VIEW Mechanical tolerances unless otherwise noted: X.XX dimensions: ±0.020 inches Environmental Case Operating Range No Derating X.XXX dimensions: ±0.005 inches Pin 1 2 3 4 5 6 7 °C °C General Unit Weight Chassis Mounting Kit Agency Approvals SIDE VIEW TYP 2.3 oz (11) MS8 (12) UL1950, see note Note: On nominal 48Vin models UL recognition only applies up to 60 VDC (13) NOTES parameters measured at Tc=25°C, nominal input * All voltage and full rated load unless otherwise noted. Refer to the CALEX Application Notes for the definition of terms, measurement circuits and other information. (1) 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 tantalum located 1" away from the converter to simulate your boards standard decoupling. Input reflected ripple is measured into a 1 µH source impedance. (2) To determine the correct fuse size, see CALEX Application Notes. (3) The Case is tied to the -Input pin. (5) Short term stability is specified after a 30 minute warmup at full load, constant line and recording the drift over a 24 hour period. (6) The transient response is specified as the time required to settle from a 50 to 75 % step load change on one output (rise time of step = 2 µSec) to a 1% error band. (7) Dynamic response is the peak overshoot during a transient as defined in note 6 above. (8) The input ripple rejection is specified for DC to 120 Hz ripple with a modulation amplitude of 1% of Vin. (10) 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 (14) Function ON/OFF -INPUT +INPUT +OUTPUT CMN -OUTPUT TRIM 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. The case thermal impedance is specified as the case temperature rise over ambient per package watt dissipated. Load regulation is defined as the voltage change on either output as the loads on both outputs are changed from 25% to 100% full load at the same time. Cross regulation is defined as the change in one output when the other output is changed from 25% to 100% full load. Specifications subject to change without notice. A Applications Information The 20 Watt NT Dual series like all CALEX converters carries the full 5 year CALEX no hassle warranty. We can offer a five year warranty where others can’t because with CALEX it’s rarely needed. General Information The 20 Watt NT Dual series is 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 pulseby-pulse current limiting and an over-temperature shutdown circuit. These protection features assure you that our 20 Watt Dual will provide you with zero failure rate operation. A fully five sided shielding, sealed, water washable case is standard along with specified operation over the full commercial 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 eco: 010403-2 20 Watt NT Dual Series DC/DC Converters General Operation Applying The Input Figure 1 shows the recommended connections for the 20 Watt NT Dual DC/DC converter. A fuse is recommended to protect the input circuit and should not be omitted. The fuse serves the purpose of preventing unlimited current from flowing in the case of a catastrophic system failure. 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 below 10 mV P-P. * * D - Overvoltage clamp is optional, see text * - No connection needed if not used. Figure 1. Standard connections for the 20 Watt NT Dual. 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. Figure 3. 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 20 K ohms nominal. The ON/OFF and 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 converters 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 1 µF to 10 µF tantalum and 0.1 to 0.001 µF ceramic bypasses may be used around your PCB as required for local bypassing without harm. Non Standard Output Voltages/Single Ended Mode The trim may be used to adjust a +5 output unit up to 5.2 volts for ECL applications or to make up for line voltage drops. +5 output units will trim around a range of approximately +4.2 to +5.3 volts. +12 volt units will trim around a range of approximately +7.4 to +12.9 volts and +15 volt units will trim around a range of approximately +8.6 to +16 volts. A Extremely low ESR capacitors (< 0.5 ohms) should not be used at the input as this will cause peaking of the input filters transfer function and actually degrade the filters performance. The dual outputs may also be used single-ended to get 10, 24 or 30 volts output at the full rated current of 1.7, 0.85 or 0.7 Amps (see figure 4). To use the single ended mode just connect your load to the + and - output terminals and leave the CMN output floating. Trimming of the output voltage may also be done while using the outputs in the single ended mode. 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 peak-peak. 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 3 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 eco: 010403-2 20 Watt NT Dual Series DC/DC Converters 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. Figure 4. To get 10, 24 or 30 volt outputs use the NT dual in the “Single Ended” mode. In this mode the load is taken across the + to - pins with the CMN pin left floating. Output Current in this mode is the full rated 1.7, 0.85 or 0.7 Amps. Output trimming may optionally be used as shown in figure 3. Figure 5. The simplified schematic of the NT Dual series ON/OFF pin. The input impedance is approximately 20 kohms. The 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. Grounding The input and output sections are fully floating from each other. They may be operated fully 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 converters 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. 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. Temperature Derating Another useful “Trick” that can be used when operating with a common ground is to use a 10 to 100 µH choke between the grounds. This gives you a solid low frequency ground connection, but looks like a high impedance to the switching current effects and prevents them from flowing in the connection. This will have the effect of preventing the common mode currents from showing up as normal mode components in your output or input circuits. Be sure that the “Q” of this inductor is quite low and that the self resonant frequency is above 220 kHz. If necessary to keep the inductor “Q” low, parallel it with a 200 ohm to 1k ohm resistor. The NT Dual series can operate up to 90°C case temperature without derating. Case temperature may be roughly calculated from ambient by knowing that the NT Duals case temperature rise is approximately 9.5°C per package watt dissipated. A 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 heatsinking? Efficiency is approximately 82%, this leads to an input power of about 18 Watts. The case temperature rise would be 3 Watts x 9.5 = 28.5°C. This number is subtracted from the maximum case temperature of 90°C to get approximately: 62°C. Case Grounding This is a rough approximation to the maximum ambient temperature. Because of the difficulty of defining ambient temperature and the possibility that the loads 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 circuits exact efficiency (efficiency depends on both line input and load value) before committing to a production design. The case serves not only as a heat sink but also as a EMI shield. The 0.016 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. This connection is shown on the block diagram. The case is floating from the output, coupled only by the 500 pF of isolation capacitance. 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 eco: 010403-2 20 Watt NT Dual Series DC/DC Converters Typical Performance (Tc=25°C, Vin=Nom VDC, Rated Load). 12 VOLT EFFICIENCY Vs. LOAD 85 12 VOLT EFFICIENCY Vs. LINE INPUT VOLTAGE 12 VOLT INPUT CURRENT Vs. LINE INPUT VOLTAGE 3.5 85 LINE = 9VDC LINE = 12VDC LINE = 18VDC 75 INPUT CURRENT (AMPS) 80 EFFICIENCY(%) EFFICIENCY (%) 50% FULL LOAD 80 100% FULL LOAD 75 3.0 2.5 100% LOAD 2.0 1.5 50% LOAD 1.0 0.5 70 70 0 10 20 30 40 50 60 70 80 90 100 0.0 9 10 11 LOAD (%) 13 14 15 16 17 18 0 24 VOLT EFFICIENCY Vs. LOAD 24 VOLT EFFICIENCY Vs. LINE INPUT VOLTAGE 80 LINE = 24VDC LINE = 36VDC 10 20 30 100% FULL LOAD 85 50% FULL LOAD 80 75 40 50 60 70 80 90 100 20 22 LOAD (%) 48 VOLT EFFICIENCY Vs. LOAD 24 26 28 30 32 34 10 20 30 INPUT CURRENT (AMPS) EFFICIENCY (%) EFFICIENCY(%) 50 60 80 50% FULL LOAD 70 80 90 100 16 20 24 28 32 36 0.75 100% LOAD 0.50 50% LOAD 0.25 0.00 36 40 LOAD (%) 44 48 52 56 60 64 68 72 0 10 20 LINE INPUT(VOLTS) 30 40 50 60 70 80 LINE INPUT (VOLTS) OUTPUT IMPEDANCE Vs. FREQUENCY DERATING 120 10 A INFINITE HEAT SINK 100 OUTPUT POWER (%) OUTPUT IMPEDANCE (OHMS) 12 48 VOLT INPUT CURRENT Vs. LINE INPUT VOLTAGE 70 40 8 1.00 85 LINE = 72VDC 0 4 LINE INPUT (VOLTS) 75 60 18 50% LOAD 0.5 0 100% FULL LOAD 70 16 100% LOAD 48 VOLT EFFICIENCY Vs. LINE INPUT VOLTAGE LINE = 48VDC 14 1.0 36 90 80 12 1.5 LINE INPUT(VOLTS) LINE = 36VDC 10 0.0 18 90 8 24 VOLT INPUT CURRENT Vs. LINE INPUT VOLTAGE 75 0 6 2.0 INPUT CURRENT (AMPS) EFFICIENCY(%) LINE = 18VDC 70 4 LINE INPUT (VOLTS) 90 85 2 LINE INPUT(VOLTS) 90 EFFICIENCY (%) 12 1 80 NO HEAT SINK ↑ 60 ← SAFE OPERATING AREA → 40 ↓ 20 .1 0 10 100 1000 10000 100000 1000000 -40 FREQUENCY (Hz) -20 0 20 40 60 80 100 AMBIENT TEMPERATURE (Deg C) NOTES ON USING THE CURVES 1) The Input currents are for 20 Watts of output power. For ±5 Volt output models the current is approximately 15% less. 2) The efficiency curves were generated for 12 Volt output models. To use for other outputs adjust as follows: ±5 Volt outputs.......Subtract approximately 3% ±15 Volt outputs.....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 eco: 010403-2