www.irf.com 1 high reliability radiation hardened dc/dc converters m3h-series description total dose > 25k rad(si) see hardened to let up to 37 mev . cm 2 /mg internal emi filter; converter capable of meeting mil-std-461c ce03 and cs01 low weight, < 125 grams magnetically coupled feedback 18v to 50v input range ( 50v, 70v, and 120v models available) up to 40w output power triple output models include +5 and 12 or 15v main output isolated from dual outputs high efficiency - to 80% -55c to +125c operating temperature range 100m ? @ 500vdc isolation under-voltage lockout short circuit and overload protection external inhibit > 1,500,000 hour mtbf features +28v input, triple output the m3h-series of dc/dc converters are radiation tolerant, high reliability devices designed for moderate radiation environments such as those encountered by low earth orbit satellites and launch vehicles. for higher radiation environments, the m3g-series of dc/dc converters is recommended. system upgrades to higher radiation tolerance applications can be easily accommodated with the m3g-series converters because they have the same mechanical outline and are pin compatible. for physically smaller, lower output power single and dual output applications the l-series of dc/dc converters are recommended. features of the m3h-series include up to 40 watt output power, small size, low weight and a high tolerance to total ionizing dose, single event effects and environmental stresses such as temperature extremes, mechanical shock, and vibration. all components are fully derated to meet the requirements of mil-std-975 and mil-std-1547. extensive documentation including radiation susceptibility, thermal analysis, stress analysis and mtbf are available. the converters incorporate a fixed frequency single forward topology with magnetic feedback and an internal emi filter. these converters are capable of meeting the conducted emissions and conducted susceptibility requirements of mil-std-461c without any additional components. all models include an external inhibit port and have an adjustable output voltage. they are enclosed in a hermetic 3.0" x 2.5" x 0.445" steel package and weigh less than 125 grams. the package utilizes rugged ceramic feed-through copper core pins and is sealed using parallel seam welding. applications low earth orbit satellites (leo) launch vehicles non-flight versions of the m3h-series converters are available for system development purposes. variations in electrical specifications and screening to meet custom requirements can be accommodated. consult ir santa clara for special requiremenrs. manufactured in a facility fully qualified to mil-prf- 38534, these converters are fabricated utilizing dscc qualified processes. for available screening options, refer to device screening table in the data sheet. m3h pd-94518c
2 www.irf.com m3h-series the m3h-series converters utilize a single forward topology with resonant reset. the nominal switching frequency is 500khz. electrical isolation and tight output regulation are achieved through the use of a magnetically coupled feedback. voltage feed-forward with duty factor limiting provides high line rejection. circuit description an internal emi filter allows the converter to meet the conducted emissions requirements of mil-std-461c on the input power leads. a two-stage output filter reduces the typical output ripple to less than 20mv peak-to-peak. an under-voltage lockout circuit prohibits the converter from operating when the line voltage is too low to maintain the output voltage. the converter will not start until the line voltage rises to approximately 17 volts and will shut down when the input voltage drops below 16 volts. the one volt of hysteresis reduces the possibility of line noise interfering with the converter?s start-up and shut down. an external inhibit port is provided to control converter operation. the converter?s operation is inhibited when this pin is pulled low. it is intended to be driven by an open collector logic device. the pin may be left open for normal operation and has a nominal open circuit voltage of 10.5v with respect to the input return (pin 2). design methodology the m3h-series was developed using a proven conservative design methodology which includes selecting radiation tolerant and established reliability components and fully derating to the requirements of mil-std-975 and mil-std-1547. heavy derating of the power mosfet gate and drain voltages minimize the possibility of segr and seb. a magnetic feedback circuit is utilized instead of opto- couplers to minimize temperature, radiation and aging sensitivity. pspice was used extensively to predict and optimize circuit performance for both beginning and end-of-life. thorough design analyses include radiation susceptibility ( tree ), stress, thermal, and reliability ( mtbf ). the main ( +5 volt ) output is regulated by the control loop and typically exhibits better than 1% regulation. the auxiliary ( 12 volt or 15 volt ) outputs are maintained through tight coupling in the power transformer and main output filter inductor and typically exhibit better than 5% regulation. the main output and auxiliary outputs are isolated from each other. output power is limited under any load fault condition to approximately 125% of rated. an overload condition causes the converter output to behave like a constant current source with the output voltage dropping below nominal. the converter will resume normal operation when the load current is reduced below the current limit point. this protects the converter from both overload and short circuit conditions. the current limit point exhibits a slightly negative temperature coefficient to reduce the possibility of thermal runaway.
www.irf.com 3 m3h-series 1 meets derating per mil-std-975 2 for operation above +85c, see table note 15 electrical performance characteristics limits parameter group a subgroup conditions -55 c t c +85 c v in = 28v dc 5%, c l = 0 unless otherwise specified min nom max unit input voltage 1,2,3 note 2 18 28 50 v output voltage ( vout ) (main) 2812t (aux.) 2815t (aux.) (main) 2812t (aux.) 2815t (aux.) 1 2,3 i out = 100% rated load, note 5 i out = 100% rated load, note 5 4.98 11.50 14.60 4.93 11.30 14.40 5.00 11.80 14.90 5.02 12.10 15.20 5.07 12.30 15.40 v output power ( p out ) 1,2,3 v in = 18, 28, 50 volts, note 2 0 40 w output current ( i out ) (main) 2812t (aux.) 2815t (aux.) 1,2,3 v in = 18, 28, 50 volts, notes 2,3,4,5 400 83 67 4000 833 667 ma line regulation ( vr line ) (main) 2812t (aux.) 2815t (aux.) 1,2,3 v in = 18, 28, 50 volts i out = 10%, 50%, 100% rated notes 5, 14 -10 -200 -200 10 200 200 mv load regulation ( vr load ) (main) 2812t (aux.) 2815t (aux.) 1,2,3 i out = 10%, 50%, 100% rated v in = 18, 28, 50 volts notes 5,13 -50 -400 -500 50 400 500 mv cross regulation ( vr cross ) 2812t (aux.) 2815t (aux.) 1,2,3 v in = 18, 28, 50 volts i out = 1a to 4a (main), 416ma on (aux.) i out = 1a to 4a (main), 333ma on (aux.) -3.5 -3.0 3.5 3.0 % input current ( i in ) 1,2,3 i out = 0, pin 3 open 80 ma pin 3 shorted to pin 2 8.0 output ripple ( v rip ) (main) 2812t (aux.) 2815t (aux.) 1,2,3 v in = 18, 28, 50 volts i out = 100% rated load, notes 5, 6 25 30 30 50 60 75 mv p-p switching frequency ( f ) 1,2,3 sync. input (pin 4) open 450 500 550 khz efficiency (e ff ) 1,2,3 i out = 100% rated load; note 5 75 79 % for notes to specifications, refer to page 4 specifications input voltage range -0.5vdc to +80vdc input voltage range +18vdc to +60vdc output power internally limited input volta g e ran g e 1 +18vdc to +50vdc lead temperature +300c for 10 seconds output power 0 to max. rated operating temperature -55c to +135c operatin g temperature 2 -55c to +125c storage temperature -55c to +135c operatin g temperature 1 -55c to +70c recommended operating conditions absolute maximum ratings
4 www.irf.com m3h-series electrical performance characteristics ( continued ) notes. electrical performance characteristics 1. parameter is tested as part of design characterization or after design changes. thereafter, parameter shall be guaranteed to the limits specified. 2. parameter verified during line and load regulation tests. 3. although operation with no load is permissible, light loading on the main (+5 volt) output may cause the output voltage of the auxiliary outputs (12 volt or 15 volt) to drop out of regulation. it is therefore recommended that at least 200 ma or 20 percent of the total o utput power, whichever is greater, be taken from the main (+5 volt) output. 4. although operation with no load is permissible, heavy loading on the main (+5 volt) output may cause the output voltage of the auxiliary outputs (12 volt or 15 volt) to rise out of regulation. it is therefore recommended that at least 50 ma or 20 percent of the total ou tput power, whichever is greater, be taken from the auxiliary (12 volt or 15 volt) outputs. 5. unless otherwise specified, ?rated? load is 20w on the main (+5 volt) output and 10 watts each on the auxiliary (12 volt or 15 volt) outputs. load currents of up to 5a and 1a on the main and auxiliary outputs respectively are acceptable as long as the total output power do es not to exceed 40 watts. 6. guaranteed for a d.c. to 20mhz bandwidth. tested using a 20khz to 10mhz bandwidth. 7. capacitive load may be any value from 0 to the maximum limit without compromising dc performance. 8. a capacitive load in excess of the maximum limit may interfere with the proper operation of the converter?s overload protecti on, causing erratic behavior during turn-on. 9. overload power threshold is defined as the load set point such that v out = 90% of nominal. 10. load step transition time 10 s. 11. recovery time is measured from the initiation of the transient to where v out has returned to within 1% of its steady state value. 12. line step transition time 100 s. 13. turn-on delay time from either a step application of input power or a logic low to a logic high transition on the inhibit pin (pin 3) to the point where v out = 90% of nominal. 14. load is varied for output under test while the remaining outputs are loaded at 50%ofrated. regulation relative to o utput voltage at 50% rated load. 15. for operation @ temperatures between +85 c and +125 c, derate the maximum input voltage linearly from 60v to 40v and the maximum output power linearly from 100% to 75%. limits parameter group a subgroup conditions -55 c t c +125 c v in = 28v dc 5%, c l = 0 unless otherwise specified min nom max unit inhibit input open circuit voltage drive current ( sink ) voltage range 1,2,3 note 1 3.0 -0.5 5.0 100 50 v a v current limit point expressed as a percentage of full rated output power 1,2,3 v out = 90% of nominal, notes 5, 9 135 % power dissipation, load fault (p d ) 1,2,3 short circuit, overload 18 w output response to step load changes (v tld ) 4,5,6 half load to/from full load, notes 5, 10,14 -300 300 mvpk recovery time, step load changes (t tld ) 4,5,6 half load to/from full load, notes 10,11,14 200 s output response to step line changes (v tln ) 4,5,6 18v to/from 50v i out = 100% rated load, notes 1,5,12 -300 300 mvpk recovery time, step line changes (t tln ) 4,5,6 18v to/from 50v i out = 100% rated load, notes 1,5,11,12 200 s turn-on response overshoot (v os ) (main) ( aux. ) 4,5,6 no load, full load; notes 5,12,13 10 10 % turn-on delay (t dly ) 4,5,6 notes 5, 12,13 1.0 10 ms capacitive load (cl) (main) (each aux. output) 1 i out = 100% rated load, no effect on dc performance, notes 1, 5, 7, 8 1000 200 f line rejection 1 i out = 100% rated load dc to 50khz, notes 1, 5 40 60 db isolation 1 input to output or any pin to case except pin 10, test @ 500vdc 100 m ? device weight 125 g mtbf mil-hdbk-217f2, sf, 35 c 1.5 x 10 6 hrs
www.irf.com 5 m3h-series radiation performance characteristics test conditions min typ highest level tested unit total ionizing dose ( gamma ) mil-std-883, method 1019 operating bias applied during exposure, full rated load, v in = 28v 25 40 60 krads (si) single event effects seu, sel, segr, seb heavy ions (let) operating bias applied during exposure, full rated load, v in = 28v 37 82 82 mev ? cm 2 /mg dose rate ( gamma dot ) temporary saturation survival mil-std-883, method 1023 operating bias applied during exposure, full rated load, v in = 28v 1e8 1e10 1.5e9 rads (si)/sec neutron fluence mil-std-883, method 1017 3e12 8e12 neutrons /cm 2 proton fluence e > 10mev tbd n/a protons /cm 2 ref ea + - main return +main 6 -aux. output aux. return +aux. output 13 1 2 vin return bias supply emi filter +10.5v pwm controller sample & hold feedback trigger ramp gen 3 inhibit uvlo & inhibit 10 case ground 5 sync. output ( for test use only ) 12 11 7 figure 1. block diagram international rectifier currently does not have a dscc certified radiation hardness assurance program.
6 www.irf.com m3h-series 10 10.5 11 11.5 12 12.5 13 13.5 14 12v magnitudes ( volts ) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 12v load current ( amps each ) 5v load = 4a 5v load = 2a 5v load = 0.4a
12v load regulaltion vs 5v load 13 13.5 14 14.5 15 15.5 16 16.5 17 17.5 18 15v magnitudes ( volts ) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 15v load current ( amps each ) 5v load = 4a 5v load = 2a 5v load = 0.4a
15v load regulaltion vs 5v load
www.irf.com 7 m3h-series 3.00 0.500 2.000 0.450 1.100 2.500 2.300 0.200 typ. non-cum. 0.300 1.400 ref. 3.50 ref. 0.445 max 0.080 max. 0.260 pin ?0.040 r0.0625 4 places 0.500 0.600 0.200 tolerance : .xx 0.01 .xxx 0.005 1 2 3 4 5 12 13 11 10 9 8 7 6 0.25 3.00 2.000 mechanical outline pin designation pin # designation pin # designation 1+ vin 8 nc 2 input return 9 nc 3 inhibit 10 case ground 4 nc 11 - aux output 5 sync. output (t.p) 12 aux output return 6 main return 13 + aux output 7 + main output
8 www.irf.com m3h-series world headquarters: 233 kansas st., el segundo, california 90245, tel: (310) 252-7105 ir santa clara: 2270 martin av., santa clara, california 95050, tel: (408) 727-0500 visit us at www.irf.com for sales contact information . data and specifications subject to change without notice. 09/2006 part numbering device screening requirement mil-std-883 method no suffix em temperature range -55c to +85c -55c to +85c element evaluation mil-prf-38534 class h w/sem n/a non-destructive bond pull 2023 yes n/a internal visual 2017 yes temperature cycle 1010 cond c cond c constant acceleration 2001, y1 axis 3000 gs 3000 gs pind 2020 n/a n/a burn-in 1015 160 hrs @ 125c 48 hrs @ 125c final electrical mil-prf-38534 -55c, +25c, -55c, +25c, ( group a ) & specification +85c +85c pda mil-prf-38534 n/a n/a seal, fine and gross 1014 a1, c cond a radiographic 2012 n/a n/a external visual 2009 yes m3h 28 0515 t /em model input voltage nominal 28 = 28v output voltage 0512 = 5v, 12v 0515 = 5v, 15v output t = triple screening level (please refer to screening table) no suffix, em notes: best commercial practice. international rectifier currently does not have a dscc certified radiation hardness assurance program.
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