NMT Series Triple Output 3W DC/DC Converters SELECTION GUIDE Order Code Nominal Input Voltage V NMT0572SC 5 NMT1272SC 12 Output Rated Output Current V -VOUT1 -VOUT2 -VOUT3 -VOUT1 -VOUT2 -VOUT3 -24 -48 -72 -24 -48 -72 Output Current1 Output Current2 Min. Load Full Load Min. Load Full Load mA mA mA mA 1.4 0.7 0.5 1.4 0.7 0.5 42 21 14 42 21 14 4.2 2.1 1.4 4.2 2.1 1.4 126 63 42 126 63 42 MTTF3 kHrs 145 145 When operated with additional external load capacitance the rise time of the input voltage will determine the maximum external capacitance value for guaranteed start up. The slower the rise time of the input voltage the greater the maximum value of the additional external capacitance for reliable start up. FEATURES RoHS compliant Triple outputs (-24V, -48V & -72V) INPUT CHARACTERISTICS Input/output isolation 1kVDC Parameter Power sharing on outputs Voltage range Industrial temperature range Ripple current (IRIPPLE) UL 94V-0 package material Internal SMD construction Toroidal magnetics No external components required Power density 1.65W/cm3 DESCRIPTION The NMT series is a range of DC/DC converters offering three output voltages of -24V, -48V and -72V from a single isolated 5V or 12V input voltage. The product is designed for use with telecommunications circuits requiring an on board supply for the -72V RING-TIP connection service generated from a nominal 5V or 12V DC input supply rail. The device also offers battery level voltages of -24V and -48V for access control and data pump IC’s. The product is packaged in an 8 pin SIP case for minimum PCB footprint. The rated power may be shared or drawn from any one output providing the total output load does not exceed 3W. Zero load input current (ICCZL) Conditions Min. Typ. Max. Units NMT0572SC NMT1272SC NMT0572SC NMT1272SC NMT0572SC, 0% output load NMT1272SC, 0% output load 4.5 10.8 5.0 12 85 66 50 27.5 5.5 13.2 V 80 50 mA Typ. Max. Units W 1.01 8 220 3.0 10 2.5 26.4 24.6 52.8 49.2 79.2 73.8 1.2 15 400 mV Typ. Max. Units mA OUTPUT CHARACTERISTICS Parameter Conditions Min. Total Rated Power (POUT) Single Channel Voltage Set Point Accuracy Total of all outputs or any single output POUT = 100mW POUT = 3W POUT = 100mW POUT = 3W POUT = 100mW POUT = 3W POUT = 100mW POUT = 3W VIN = 90% to 110% of nominal POUT = 100mW to 3W DC to 20MHz single channel (24V) 0.1 0 -7.5 24 22.2 48 44.4 72 66.6 Output Voltage - VOUT1 Output Voltage - VOUT2 Output Voltage - VOUT3 Line regulation Load regulation Ripple & Noise % V % ISOLATION CHARACTERISTICS Parameter Conditions Min. Isolation test voltage Flash tested for 1 second NMT0572SC, 1MHz, 1V NMT1272SC, 1MHz, 1V 1000VDC 1000 Isolation Capacitance Insulation Resistance 1 VDC 65 130 10 pF GΩ ABSOLUTE MAXIMUM RATINGS Short-circuit protection4 Lead temperature 1.5mm from case for 10 seconds Input Voltage VIN, NMT0572SC Input voltage VIN, NMT1272SC For full details go to www.murata-ps.com/rohs www.murata-ps.com 1 second 300°C 7V 15V 1. Assuming all 3 channels are equally loaded. 2. Assuming only 1 channel is loaded. 3. Calculated using MIL-HDBK-217F with nominal input voltage at full load. 4. Supply voltage must be disconnected at the end of the short circuit duration. All specifications typical at TA=25°C, nominal input voltage and rated output current unless otherwise specified. Technical enquiries - email: [email protected], tel: +44 (0)1908 615232 KDC_NMTC.E02 Page 1 of 4 NMT Series Triple Output 3W DC/DC Converters GENERAL CHARACTERISTICS Parameter Conditions Efficiency Switching frequency All channels or any single channel Min. Typ. 75 85 85 Min. Typ. Max. Units % kHz TEMPERATURE CHARACTERISTICS Parameter Conditions Operating temperature Storage Case temperature rise above ambient Max. -40 -50 Units 85 125 1 litre static air chamber °C 27 OUTPUT VOLTAGE CONFIGURATION Although the output is described for negative rails, the input and output circuits are iternally isolated hence positive rails can also be generated, or a mixture of positive and negative. The output +VOUT rail reference can be taken from any of the output terminals to give the range of outputs as described in the Output Voltage Configurations table below. Channel Name Standard Ref Option 1 Option 2 Option 3 OV +24V +48V +72V +VOUT -VOUT1 -VOUT2 -VOUT3 -24V -48V -72V OV -24V -48V +24V OV -24V +48V +24V OV POWER SHARING The 3W total power delivery can be taken from either a single channel, or from any combination of all three channels. This allows an enormous amount of flexibility, especially when combined with the selectable output OV reference. For example, using the option 2 output configuration; -24V at 0.5W, +24V at 1W and +48V at 1.5W power supplies are available from a single NMT device. PERFORMANCE CHARACTERISTICS NMT1272SC - Channel -VOUT1 (24V NOM) 0VUQVU7PMUBHF7 &GmDJFODZ 0VUQVU7PMUBHF7 &GmDJFODZ NMT0572SC - Channel -VOUT1 (24V NOM) 0VUQVU1PXFS8 0VUQVU1PXFS8 0VUQVU1PXFS8 0VUQVU7PMUBHF7 &GmDJFODZ www.murata-ps.com 0VUQVU1PXFS8 0VUQVU7PMUBHF7 &GmDJFODZ 0VUQVU7PMUBHF7 NMT1272SC - Channel -VOUT3 (72V NOM) 0VUQVU1PXFS8 0VUQVU1PXFS8 0VUQVU1PXFS8 NMT0572SC - Channel -VOUT3 (72V NOM) 0VUQVU1PXFS8 NMT1272SC - Channel -VOUT2 (48V NOM) 0VUQVU1PXFS8 0VUQVU7PMUBHF7 &GmDJFODZ 0VUQVU1PXFS8 NMT0572SC - Channel -VOUT2 (48V NOM) &GmDJFODZ 0VUQVU1PXFS8 0VUQVU1PXFS8 Technical enquiries - email: [email protected], tel: +44 (0)1908 615232 KDC_NMTC.E02 Page 2 of 4 NMT Series Triple Output 3W DC/DC Converters APPLICATION NOTES RIPPLE SPECIFICATION The output ripple for the NMT series is higher than standard for a Murata Power Solutions DC/DC converter. This is due to using low value ceramic capacitors internally for longer life perfomance of the component and the superimposition of ripples between each output channel. Consequently with a maximum 400mV ripple per output channel, at -72V the ripple is potentially three times this value (1.2V). The ripple will always be additively superimposed since the output windings are synchronized. To reduce ripple, external capacitors are recommended with a value of 1μF per channel (see figure 1). This typically reduces the ripple to 50mV per channel. Further ripple reduction can be achieved by use of series inductors on each output channel plus additional external capacitors to form a pi-filter with the internal capacitors of the device. SLIC CIRCUITS Figure 1. VOUT3 Output Ripple Top: No external capacitors Bottom: 1μF per channel external capacitors The primary application for the NMT series is in subscriber line interface circuits (SLIC’s), particularly for the Integrated Services Digital Network (ISDN). The NMT can also be used in standard telecommunications circuits where a local power source is preferred to the telephone system power due to either the power quality of the telecommunications system power supply or to avoid potential power line disturbances, such as lightening strikes and access switching, which will effect the target circuit function. /.54$ 7*/ Another application area is in fibre-in-the-loop (FITL) or radio-in-the-loop (RITL) interfacing via a standard telecommunication SLIC, where the usual telecommunication battery voltage is not available due to the transmission media in use (fibre or radio). In particular, FITL/RITL interfaces directly on PC cards, in local monitor and boost circuits and at exchanges between the fibre/radio and wire media. %$ 7*/ %$ ".%"N3 7 7#"5 7065 7 7065 7 7#"5 7065 5*1 # 7/&( 07 The supply rails can be used for ringing generators as well as SLIC circuits or where both are combined, such as in the AMD AM79R79 Ringing SLIC device (see figure 2). The -72V rail is used primarily for the generation of the ringing signal (VBAT1), the -48V rail is used to supply in line access circuitry (VBAT2) and the -24V supply for the on-chip regulator for the logic interface (VNEG). Alternative devices from other manufacturers could use the -24V output for their internal circuit supply and -72V for ringing. " #(/% 3*/( Figure 2. Supply for Ringing SLIC Device TECHNICAL NOTES ISOLATION VOLTAGE ‘Hi Pot Test’, ‘Flash Tested’, ‘Withstand Voltage’, ‘Proof Voltage’, ‘Dielectric Withstand Voltage’ & ‘Isolation Test Voltage’ are all terms that relate to the same thing, a test voltage, applied for a specified time, across a component designed to provide electrical isolation, to verify the integrity of that isolation. Murata Power Solutions NMT series of DC/DC converters are all 100% production tested at their stated isolation voltage. This is 1kVDC for 1 second. A question commonly asked is, “What is the continuous voltage that can be applied across the part in normal operation?” For a part holding no specific agency approvals, such as the NMT series, both input and output should normally be maintained within SELV limits i.e. less than 42.4V peak, or 60VDC. The isolation test voltage represents a measure of immunity to transient voltages and the part should never be used as an element of a safety isolation system. The part could be expected to function correctly with several hundred volts offset applied continuously across the isolation barrier; but then the circuitry on both sides of the barrier must be regarded as operating at an unsafe voltage and further isolation/insulation systems must form a barrier between these circuits and any user-accessible circuitry according to safety standard requirements. REPEATED HIGH-VOLTAGE ISOLATION TESTING It is well known that repeated high-voltage isolation testing of a barrier component can actually degrade isolation capability, to a lesser or greater degree depending on materials, construction and environment. The NMT series has toroidal isolation transformers, with no additional insulation between primary and secondary windings of enameled wire. While parts can be expected to withstand several times the stated test voltage, the isolation capability does depend on the wire insulation. Any material, including this enamel (typically polyurethane) is susceptible to eventual chemical degradation when subject to very high applied voltages thus implying that the number of tests should be strictly limited. We therefore strongly advise against repeated high voltage isolation testing, but if it is absolutely required, that the voltage be reduced by 20% from specified test voltage. This consideration equally applies to agency recognized parts rated for better than functional isolation where the wire enamel insulation is always supplemented by a further insulation system of physical spacing or barriers. www.murata-ps.com Technical enquiries - email: [email protected], tel: +44 (0)1908 615232 KDC_NMTC.E02 Page 3 of 4 NMT Series Triple Output 3W DC/DC Converters PACKAGE SPECIFICATIONS MECHANICAL DIMENSIONS PIN CONNECTIONS - 8 PIN SIP 0.858 (21.80) 0.295 (7.50) 0.437 (11.10) NMT0572SC 0.022 (0.55) 0.018 (0.45) XYYWW 1 2 Pin Function 1 2 5 6 7 8 +VIN -VIN +VOUT -VOUT1 -VOUT2 -VOUT3 TUBE OUTLINE DIMENSIONS 5 6 7 8 0.022 (0.55) 0.018 (0.45) 0.181 (4.60) 0.142 (3.60) 0.046 (1.17) 0.0118 (0.30) 0.0078 (0.20) 0.083 (2.10) All dimensions in inches ±0.01 (mm ±0.25mm). All pins on a 0.1 (2.54) pitch and within ±0.01 (0.25) of true position. Weight: 3.85g Unless otherwise stated all dimensions in inches ±0.02 (mm ±0.5mm). Tube length : 20.47±0.079 (520mm±2mm). Tube Quantity : 23 RECOMMENDED FOOTPRINT DETAILS` RoHS COMPLIANT INFORMATION )0-&4 This series is compatible with RoHS soldering systems with a peak wave solder temperature of 300ºC for 10 seconds. The pin termination finish on this product series is Tin Plate, Hot Dipped over Matte Tin with Nickel Preplate. The series is backward compatible with Sn/Pb soldering systems. For further information, please visit www.murata-ps.com/rohs Unless otherwise stated all dimensions in inches ±0.02 (mm ±0.5mm). USA: Mansfield (MA), Tel: (508) 339-3000, email: [email protected] Canada: Toronto, Tel: (866) 740 1232, email: [email protected] Murata Power Solutions, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A. Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356 www.murata-ps.com email: [email protected] ISO 9001 REGISTERED Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. © 2008 Murata Power Solutions, Inc. www.murata-ps.com UK: Milton Keynes, Tel: +44 (0)1908 615232, email: [email protected] France: Montigny Le Bretonneux, Tel: +33 (0)1 34 60 01 01, email: [email protected] Germany: München, Tel: +49 (0)89-544334-0, email: [email protected] Japan: Tokyo, Tel: 3-3779-1031, email: [email protected] Osaka, Tel: 6-6354-2025, email: [email protected] Website: www.murata-ps.jp China: Shanghai, Tel: +86 215 027 3678, email: [email protected] Guangzhou, Tel: +86 208 221 8066, email: [email protected] Technical enquiries - email: [email protected], tel: +44 (0)1908 615232 KDC_NMTC.E02 Page 4 of 4