size (max.): 3.20 x 2.46 x 0.595 inches (81.3 x 62.5 x 15.11 mm) see case l for dimensions. weight: 140 grams typical screening: standard or es. see screening table for more information. models vdc o u t p u t d u a l 12 15 triple +5 & 12 +5 & 15 description the m fw series? of dc/d c converters offers up to 70 watts of power from dual or triple outputs in one package. using hybrid thick film tech - nology a power density of over 20 watts per cubic inch is achieved. these devices are packaged in hermetically sealed cold rolled steel enclosures with a tin plate finish making them ideal for use in military, aerospace, or other high reliability applications. unscreened models are guaranteed to pass a gross leak test (maximum leak rate of 0.001 atm-cc/sec). environmentally screened units (designated by the /es suffix) are hermetically solder sealed. see section c2 for screening specifications. d e s i g n m e t h o d o l o g y the m fw series converters utilize a quasi-square wave forward converter design with a nominal switching frequency of 245 khz. isolation between input and output is provided with a transformer in the forward power loop and a wideband, temperature insensitive optical link in the feedback control loop. o utput regulation is accomplished with constant frequency pulse width modulation. in addition, the load regulation of the single output models is further enhanced through the use of remote output voltage sense pins to overcome the adverse effects of line resistance voltage drops. short circuit protection is provided by detecting peak primary switching current on a cycle by cycle basis and limiting it to approximately 130% of the full load input current. this method results in quick and positive current limiting under short circuit conditions. l o w n o i s e the m fw series converters offer low noise on both the input and output lines. a two section, four pole lc input filter is included to provide very low reflected line ripple current. adherence to mil-std- 461c (ce03) is possible with the addition of the f m b-461 filter. output ripple is maintained at less than 50 mv p-p for single and dual output models and 85 mv for triple output models. w i d e v o l t a g e r a n g e all models of the m fw series are designed to provide full power operation over an input voltage range of 19 to 40 v dc. operation below an input of 19 volts, including operation in mil-std -704e emer- gency power conditions, is possible with derated output power. please refer to the derating information and the low voltage drop-out graphs (figures 10 and 11) on the following pages. w i d e t e m p e r a t u r e r a n g e full load operation of any of the m fw series converters is available at case temperatures of C55c to + 85c. o peration up to +125c is possible with derated output power. the m fw series converters are provided in a flange mount case designed to facilitate the removal of internally generated heat. because of this, heat sinking requirements are minimal. sustained full power operation does however require that an efficient heat sink be attached to the baseplate. please refer to the heat sink requirements section for more information. i n h i b i t /s y n c f e a t u r e standard on all models of the m fw series is a dual mode inhibit/sync pin. this pin serves as both an output inhibit and as a synchronization input. in the inhibit mode an open collector ttl compatible low (<0.8 v) will disable internal switching thereby inhibiting the units output. inhibiting in this manner results in an extremely low quiescent current. since a pull-up resistor is included internally, this pin may be left open should the inhibit function not be desired. in a digital system it is often desirable to synchronize the input or output ripple with the system clock. for this reason each model of the m fw series was designed to synchronize with a system clock applied to the inhibit/sync pin. please refer to the technical data section for timing details for the external sync feature. features ? C55c to + 85c operation ? 19 to 40 vdc input ? 50 v for 50 ms transient protection ? fully isolated ? fixed frequency switching ? remote sense on single models ? inhibit/sync function ? indefinite short circuit protection ? up to 84% efficiency mfw series 70 w att dc/dc c o n v e r t e r s 28 v o l t i n p u t not recommended for new designs page 1 of 7 mfw rev f 20100212 crane aerospace & electronics electronics group (interpoint brand) po box 97005 ? redmond wa 98073-9705 425.882.3100 ? power@crane-eg.com www.interpoint.com
sync and inhibit derating output power/c urrent and input voltage recommended o perating conditions abso lute maximum ratings typical characteristics output power ? 60 to 70 watts depending on model lead s oldering t emperature (10 sec per lead) ? 300c storage temperature r ange (case) ? C55c to +125c o utput voltage temperature coefficient ? 150 ppm/c, typical i nput to output capacitance ? 160 pf, typical isolation ? 100 megohm minimum at 500 v c onversion frequency ? free run mode 245 khz, typical inhibit p in voltage (unit enabled) ? 4.5 to 5.5 v sync i n (245 to 370 khz.) ? duty cycle 70% min, 98% max. ? logic low 0.8v max ? logic high 4.5 v min ? referenced to input common ? if sync is not used, leave unconnected inhibit ttl open collector ? logic low (output disabled) inhibit pin current 1 ma max ? referenced to input common ? logic high (output enabled) v = 4.5v t emperatures are referenced to the temperature at the converters base- plate ? linearly derate output power/current from 100% at 85c to 0% at 125c. ? above 105c linearly derate steady state input voltage to 33 volts at 125c. ? indefinite short circuit protection is not guaranteed above 85c case. ? operation below an input voltage of 19 volts, including operation in mil- std -704e emergency power conditions, is possible with derated output power. see figures 10 and 11. i nput voltage range ? 19 to 40 vdc continuous (see derating) case operating t emperature (tc) ? C40c to +85c full power mfw series 70 w att dc/dc c o n v e r t e r s page 2 of 7 mfw rev f 20100212 www.interpoint.com
electrical characteristics: 25c tc, 28 v d c vin, 100% load, free run, unless otherwise specified. notes 1. o n dual output models the maximum combined output power is 70 watts. a maximum of 95% (66.5 w) is available from any single output. 2. o n triple output models the maximum combined output power is 60 watts. a maximum of 50 watts is available from a single output. 3. balanced loads 4. regulation effect on the negative dual output during the defined conditions. 5. regulation effect on both dual outputs during the defined conditions. dual a nd triple output models mfw2812d mfw2815d mfw2812t mfw2815t units parameter conditions min typ max min typ max mi n typ m ax mi n typ m ax o u t p u t v o l t a g e f u l l l o a d m a i n 11.88 12 12.12 14.85 15 15.15 4.95 5.05 5.10 11.65 11.80 12.05 4.90 4.95 5.05 15.05 15.30 15.55 vdc d u a l o u t p u t c u r r e n t 1,2 v i n = 19 t o 40 m a i n 2.92 5.5 2.33 4.4 4.0 10.0 1.67 4.2 4.0 10.0 1.33 3.33 a d u a l o u t p u t p o w e r 1,2 m a i n 35 66.5 70 35 66.5 70 20 50 20 50 60 20 50 20 50 60 w d u a l t o t a l o u t p u t r i p p l e f u l l l o a d b w 2 mhz m a i n 30 50 30 50 50 85 50 85 50 85 50 85 mv p-p d u a l l i n e r e g u l a t i o n v i n = 19 t o 40 m a i n 10 25 10 25 2 20 100 200 2 20 100 200 mv d u a l l o a d r e g u l a t i o n 3 n o l o a d t o f u l l m a i n 25 50 25 50 5 20 480 600 5 20 300 450 mv d u a l c r o s s r e g u l a t i o n 4 d u a l + p o = 3 w t o 35 w - p o = 35 w 1.5 3.0 2.0 4.0 1.5 3.0 2.0 3.5 % + p o = 20 w t o 50 w - p o = 50 w t o 20 w c r o s s r e g u l a t i o n 5 m a i n + p o = 33 w d u a l + p o = 3 w t o 27 w - p o = 27 w t o 3 w 2.3 6.0 5.4 9.0 2.3 5.0 5.0 7.0 % m a i n + p o = 3 w t o 30 w d u a l p o = 15 w i n p u t v o l t a g e 19 28 40 19 28 40 19 28 40 19 28 40 vdc i n p u t c u r r e n t n o l o a d 75 90 30 35 75 90 30 35 60 110 30 35 60 110 30 35 ma i nh i b i t ed i n p u t r i p p l e c u r r e n t f u l l l o a d b w 10 mhz 15 40 15 40 15 40 15 40 ma p-p e f f i c i e n c y 80 83 80 83 80 84 80 84 % s t a r t u p d e l a y 15 25 15 25 6 10 6 10 ms mfw series 70 w att dc/dc c o n v e r t e r s page 3 of 7 mfw rev f 20100212 www.interpoint.com
thermal management c a l c u l a t i n g m a x i m u m a m b i e n t t e m p e r a t u r e the m fw series of dc/d c converters has an upper operating temperature of + 85c at the baseplate of the case. the degree of heat sinking required to remain within this limit may be determined from figure 1 which shows the maximum allowed internal power dissi - pation (p diss vs. ambient temperature for various heat sink thermal resistances. p diss may be calculated as: p diss = p out / efficiency C p out the efficiency for all combinations of p o ut and vin for the various models may be obtained from the graphs on the preceding pages. example: converter = mfw2815d , t amb = 70c, v in = 28 v d c, p out = 45 watts efficiency = 85% (from figure 7) p diss = (45 / 85) C 45 = 7.95 watts from figure 1 we can see that this situation will require thermal resis - tance of approximately 4.5c / watt. conversely we may also find the maximum ambient temperature which can be tolerated if we know the heat sink thermal resistance. example: converter = m fw2805s, vin = 28 vd c, p out = 45 w. thermal resistance = 3c / watt. efficiency = 83.5% (from figure 3) p diss = (45 / 0.835) C 45 = 8.89 watts. from figure 1 we can see that the maximum allowed am bient temper - ature is ap prox imately 75c. h e a t s i n k r e c o m m e n d a t i o n s an m fw series converter in still air (other than convective currents) and with no conductive cooling paths other than through electrical connections at the pins will exhibit a thermal resistance of approxi - mately 4c / watt. in cases where this value proves to be too high it is recommended that additional heat sinking be supplied. the simplest method of accomplishing this is to firmly attach the converter to a pcb thereby providing a conductive thermal path. secondly it is recom - mended that airflow be provided over the converter. although each situation requires a thorough thermal analysis these two measures can reduce the thermal resistance to as low as 2c / watt. if calcula - tions indicate further heat sinking is required it is recommended that additional thermal mass be provided either under the base plate or on top of the converters mounting flanges or both. degrees centigrade watts 20 40 60 80 100 120 140 20 15 10 5 u=4 c/ w u= 3 c/w u= 2c/ w u=0 c/ w internal power dissipation (max) vs. ambient t emperature f i g u r e 1 pin out f i g u r e 2: p in o u t see case l for dimensions. p in d ual output t riple output 1 positive input positive input 2 case ground case ground 3 input common input common 4 inhibit/sync in inhibit/sync in 5 negative output neg. aux. output 6 positive output positive aux. output 7, 8 o utput common o utput common 9, 10 no connection m ain (+5) output squared corner indicates pin one. bottom view mfw 12 34 5 6 7 8 9 10 mfw series 70 w att dc/dc c o n v e r t e r s page 4 of 7 mfw rev f 20100212 www.interpoint.com
typical performance curves: 25c tc , 28 v d c vin, 100% load, free run, unless otherwise specified. f i g u r e 3 10 20 30 40 50 60 70 87 85 83 81 79 77 75 73 71 40 v 28 v 19 v efficiency (%) output power (watts) mfw2812d efficiency vs line & load f i g u r e 5 10 20 30 40 50 60 70 87 85 83 81 79 77 75 73 71 40 v 28 v 19 v efficiency (%) output power (watts) mfw28512t efficiency vs line & load 10 20 30 40 50 60 70 87 85 83 81 79 77 75 73 71 40 v 28 v 19 v efficiency (%) output power (watts) mfw2815d efficiency vs line & load f i g u r e 4 10 20 30 40 50 60 70 87 85 83 81 79 77 75 73 71 40 v 28 v 19 v efficiency (%) output power (watts) mfw28515t efficiency vs line & load f i g u r e 6 input voltage (volts) 15 10 20 30 40 50 60 70 16 17 18 283r5s 2815s 2812s 2805s output power (watts) low line dropout vs. load (50 mv drop) mfw single output models f i g u r e 7 f i g u r e 8 15 10 20 30 40 50 60 70 16 17 18 19 mfw2815d mfw2812d mfw28512t mfw28515t input voltage (volts) output power (watts) low line dropout vs. load (50 mv drop) mfw dual and triple output models mo del numbering key mfw 28 512 t / es base model input voltage output voltage screening number of outputs (d = dual, t = triple) (main and aux. vout for triple models) (standard screening has no designator in this position.) mfw series 70 w att dc/dc c o n v e r t e r s page 5 of 7 mfw rev f 20100212 www.interpoint.com
solder seal solder t ip-of f 2.850 (72.39) 0.550 (13.97) 1.600 (40.64) 0.350 (8.89) 0.000 0.00 0.000 0.180 (4.57) 0.040 +0.007/-0.000 (1.02 +0.18/-0.00) 0.595 max (15. 11) 0.250 +0.05/-0.00 (6.35 +1.3/-0.0) 0.625 (15.88 ) 0.825 (20.96) 1.025 (26.04) 1.325 (33.66 ) 1.425 (36.20) 1.625 (41.28) 2.280 (57.91) .0.040 +0.005/-0.002 (1.02 +0.13/-0.05) bott om view 12 34 5 6 7 8 9 10 squared corner indicates pin one case l 0.141 dia. x 6 (3.58) 2.460 max (62.50) 3.20 max (81.3) case dimensions in inches (mm) to lerance 0.005 (0.13) for three decimal places 0.01 (0.3) for two decimal places unless otherwise specified caution heat from reflow or wave soldering may damage the device. solder pins individually with heat application not exceeding 300c for 10 seconds per pi n materials header cold rolled steel/nickel/t in cover cold rolled steel/nickel/t in pins #52 alloy pins 1-4, and 9-10 #52 alloy with copper core pins 5-8, ceramic seal case l, rev c, 20060803 please refer to the numerical dimensions for accurac y. all information is believed to be accurate , but no responsibility is assumed for errors or omissions. interpoint reserves the right to make changes in products or specifications without notice . copyright ? 1999-2006 interpoint corp. all rights reserved. f i g u r e 9: c a s e l mfw series 70 w att dc/dc c o n v e r t e r s page 6 of 7 mfw rev f 20100212 www.interpoint.com
s t a n d a r d a n d /es ( n o n -qml) p r o d u c t s e n v i r o n m e n t a l s c r e e n i n g 1 test performed standard non-qml 2 /es non-qml 2 pre-cap inspection method 2017, 2032 yes yes temperature cycle (10 times) method 1010, cond. b, -55c to +125c, ambient no yes constant acceleration method 2001, 500 g no yes burn-in method 1015 3 96 hours no yes final electrical test mil-prf-38534, group a subgroups 1 and 4: +25c case yes yes hermeticity test fine leak, method 1014, cond. a gross leak, method 1014, cond. c gross leak, dip (1 x 10 -3 ) no no yes yes yes no final visual inspection method 2009 yes yes test methods are referenced to mil-std-883 as determined by mil-prf-38534. notes: 1. efers to products that do not offer ml screening. 2. standard and /es, non-qml products, do not meet all of the requirements of mil-prf-38534. 3. burn-in designed to bring the case temperature to the maximum case temperature of the product. refer to the specific product information for the maximum case temperature. test methods are referenced to mil-std-883 as determined by mil-prf-38534. notes: 1. efers to products that do not offer m l screening. 2. standard and /es, non-qml products, do not meet all of the requirements of mil-prf-38534. 3. burn-in designed to bring the case temperature to the maximum case temperature of 85c. mfw series 70 w att dc/dc c o n v e t e s page 7 of 7 mfw series dc/dc converters, mfw rev f 20100212. this revision supersedes all previous releases. all technical information is believed to be accurate, but no responsibility is assumed for errors or omissions. interpoint reserves the right to make changes in products or specifications without notice. m fw series is a trademark of interpoint. copyright ? 1999 - 2010 interpoint corporation. all rights reserved. www.interpoint.com
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