2.1 - 1 2.1 low profile hermetic dc/dc converter +5, +12, and +15 volt in a metal package 4 11 r0 low profile dc/dc converter in a hermetic metal package features ? up to 20 watts output power ? 5, 12, 15 vdc outputs ? mil-std-704d compatible ? navmat p-4855-1a component derating ? ultra-low profile: 0.385" height ? constant frequency pwm design ? seam welded case for enhanced reliability ? low voltage lockout ? 16 to 40 vdc input range ? -55 to +125c full power operation ? up to 81% efficiency ? industry standard pin-outs ? magnetic feedback ? short circuit current limiting protection ? cascaded dual loop control scheme for superior load transient characteristics ? available hi-rel screened description omnirels ohd2800s series of dc/dc converters are rated up to 20 watts of output power over the full military temperature range. these converters are supplied in a fully hermetic, ultra-low profile package to produce a power density of up to 22 watts per cubic inch. maximum ratings (t = 25c, v in = 28 vdc unless otherwise specified) operating temperature range .................................. -55c to +125c (t case ) storage temperature range .......................................... -65c to +150c isolation ......................................................... >100 m @ 500 vdc conversion frequency: free run mod e....................................... 400 khz conversion frequency sync. mode ................................. 425 khz - 525 khz ohd2815s ohd2805s ohd2812s
2.1 - 2 ohd2805s ohd2812s ohd2815s electrical characteristics parameters conditions ohd2805s ohd2812s ohd2815s units input voltage range no load to full load 16 to 40 16 to 40 16 to 40 vdc -55c to +125c max. input current no load 40 50 60 ma max. input ripple current full load 25 25 25 map-p dc to 2 mhz output voltage full load 5.0 (3%) 12.0 (2%) 15.0 (2%) vdc min. output power v in = +16 vdc to +40 vdc 15 20 20 w -55c to +125c min. output current v in = +16 vdc to +40 vdc 0 to 3.0 0 to 1.67 0 to 1.33 a -55c to +125c max. output ripple full load 35 35 35 mvp-p voltage dc to 2 mhz max. load regulation no load to full load 15 15 15 mv max. line regulation full load 10 10 10 mv typ. efficiency full load 79 81 81 % step load response typ. transient no load to full load 200 250 300 mv full load to no load typ. recovery no load to full load 65 65 65 s full load to no load 2.1 block diagram input filter pwm error amp & ref. output filter 1 2 9 10 4 3 5
2.1 - 3 ohd2805s ohd2812s ohd2815s topology the ohd2800s series is a single ended forward converter operating at a nominal oscillator frequency of 400 khz. these fixed frequency converters use a resonant transformer reset circuit which allows for a maximum duty cycle of 67% without increasing the voltage stress on the primary mosfet or output rectifiers. tight line and load regulation are achieved through wide bandwidth magnetic feedback circuit. this magnetic feedback circuit, in conjunction with bipolar control ics, offers greater long term reliability and radiation tolerance when compared to converters using an optocoupler feedback circuit and/or cmos control ics. high reliability design omnirels ohd2800s series of dc/dc converters are designed to achieve the high reliability demanded by military programs. the case is resistance seam welded for superior long term hermeticity. the converters use only ceramic input capacitors to provide high product reliability over the military temperature range of - 55c to +125c. all semiconductor devices are of the highest level of performance and reliability. omnirels converters are designed in accordance with the navmat p-4855-1a component derating guidelines when operating over the mil- std-704d input voltage range. the converters meet the conducted emissions (ce03) noise limits of mil-std-461c when operated with omnirels ofc461 emi filter module. flexible synchronization the ohd2800s series offers two different synchronization options. the standard ohd2800s can be synchronized to an external system clock for any rate between 425 khz and 525 khz. a second option allows the system designer to synchronize multiple slave converters to one master converter. the appropriate parts must be ordered to utilize this master/slave configuration. a suffix of -mst is added for the master part number and -slv suffix for the slave part number. example: part no.: ohd2805s-mst description: master synch. config. inhibit feature the ohd2800s series of converters provide an active low (<0.8 v) inhibit pin that can be used to disable the converter, resulting in a zero output voltage and very low quiescent current. low voltage lockout omnirels ohs2800s series of converters are designed to operate from an input voltage of 16 to 40 vdc. the converter will not start until the input voltage reaches approximately 15 vdc. once operating, the unit will shut down when the input voltage drops below approximately 14 vdc. 2.1
ohd2805s ohd2812s ohd2815s 2.1 205 craw ford street, leominster, ma 01453 usa (508) 534-5776 fax (508) 537-4246 .155 .400 .800 1.110 pin 8 brazed to frame 1.600 .255 .400 8 plcs. .255 2.110 c/l bottom view .390 max. .260 .010 .038 .042 dia. 10 plcs. side view pin ohd2805s ohd2812s/ohd2815s 1 + input + input 2 inhibit input inhibit input 3 output adjust n/c 4 output common output common 5 + output + output 6 n/c n/c 7 n/c n/c 8 case ground case ground 9 sync sync 10 input common input common ohd - xxx model 28 input voltage xx output voltage s outputs s = single d = dual x package style f = flange option blank for standard package synchronization mst = master slv = slave blank for standard package 05 = 5 vdc 12 = 12 vdc 15 = 15 vdc mechanical outline pin connection ordering information 12 3 45 10 9 8 7 6
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