da7228_001.doc october 6, 2008 1/4 000072281161 ecn 1145 ms7228 pressure sensor die (0-28 bar) for harsh environment ? 0 to 2800 kpa range (28 bar or 406 psi) ? absolute pressure sensors ? hermetic sensor ? rohs-compatible & pb-free 1 description the ms7228 is an absolute silicon micro-machined pr essure sensor for harsh environment. a vacuum refer ence cavity is sealed on top of the sensitive silicon me mbrane by the anodic bonding of a pyrex? cap. the p ressure, applied on the backside, is converted in electrical signal by piezo-resistors implanted in the silicon membrane. to improve the sensor stability, a drilled pyrex? i s bonded on the backside. as the pressure port cons ists of pyrex? and silicon, both stable in most of the chem icals, the ms7228 is suitable for media-resistive applications. features ? media resistive pressure sensor die ? linearity 0.05% (typical) ? output span 150mv @ 5 v ? die size 1.63 x 1.95 mm 2 ? temperature range -40?+125c ? low cost, high reliability application ? harsh environments ? tire pressure ? absolute pressure sensor systems ? engine controls ? braking systems ? diving computers electrical connections positive output for pressure applied backside 1 the european rohs directive 2002/95/ec (r estriction o f the use of certain h azardous s ubstances in electrical and electronic equipment) bans the use of lead, mercury, cadmium, hexavalent chromium and polybrominated biphenyls (pbb) or poly brominated diphenyl ethers (pbde). vs+ : supply voltage of wheatstone bridge epi : connection of epitaxial layer (membrane) out- : negative output out+ : positive output gnd1 : ground gnd2 : ground vs+ gnd2 gnd1 out + epi out -
da7228_001.doc october 6, 2008 2/4 000072281161 ecn 1145 pad out ms7228 vs+ out+ epi out- gnd1 gnd2 important remarks: as the sensing elements are diffused resistances, t he voltage applied on the ground pads (gnd1 and gnd2) has to b e lower than the voltage applied on supply voltage pad (vs+ ). the epitaxial layer is connected to the vs+ pin on the die. layout
da7228_001.doc october 6, 2008 3/4 000072281161 ecn 1145 full scale pressure kpa bar mbar psi atm mm hg m h 2 o inches h 2 o 2800 28 28000 406 27.5 21002 285 11242 absolute maximum ratings parameter symbol conditions min max unit supply voltage vs+ ta = 25 o c 20 v storage temperature t s -40 +150 o c pressure overload 70 bar electrical characteristics (reference conditions: supply voltage vs+ = 5 vdc; ambient temperature ta = 25c ) parameter min typ max unit notes operating pressure range 0 28 bar operating temperature range -40 125 c bridge resistance 3.0 3.4 3.8 k full-scale span (fs) 100 130 160 mv zero pressure offset -40 0 40 mv linearity 0.05 0.15 % fs 1 temperature coefficient of resistance span offset + 2400 - 1500 - 80 + 2800 - 1900 + 3300 - 2300 + 80 ppm/c ppm/c v/c 2 pressure hysteresis 0.05 0.15 % fs 3 repeatability 0.05 0.15 % fs 4 temperature hysteresis 0.3 % fs 5 notes 1) deviation at one half full-scale pressure from the least squares best line fit over pressure range (0 to 28 bar). 2) slope of the endpoint straight line from 25c t o 60c. 3) output deviation at any pressure within the spe cified range, when this pressure is cycled to and f rom the minimum or maximum rated pressure, at 25c. 4) same as 3) after 10 pressure cycles 5) maximum difference in offset after one thermal cycle from -40c to +125c.
da7228_001.doc october 6, 2008 4/4 000072281161 ecn 1145 picking tools the ms7228 sensors have a topside pyrex? cap (1.23 x 1.02 mm 2 ) and a backside pyrex? (1.95 x 1.63 mm 2 ). the pick and place tool has to be of a soft materia l as rubber (hardness 78-97 shore a). its external size must fit the pyrex? cap. successful tests were done with some tools of spt (see spt drawing and references bellow). spt references rtr-a1-060x060 external dimension tl & tw: 0.06 inch /1.52 mm internal dimensions ? h: 0.035 inch / 0.89 mm wire bonding the bondable area is 100 x 100 m 2 . the location of the bonding pads is close to the top pyrex glass edge reducing the possible size and angle of the bonding capillary. refer to the detail view d on the layout for more precision. ordering information product code type product art.-nr. MS7228-A absolute 28 bar pressure sensors sawn on b /f 722825021 the ms7228 dice are supplied sawn on blue foil, mou nted on plastic rings factory contacts intersema sensoric sa ch. chapons-des-prs 11 ch-2022 bevaix switzerland tel. 032 847 9550 tel. int. +41 32 847 9550 telefax +41 32 847 9569 e-mail: http://www.intersema.ch notice intersema reserves the right to make changes to the products contained in this data sheet in order to improve the design or performance and to supply the best possible products. intersema assumes no responsibility for the use of any circu its shown in this data sheet, conveys no license under any patent or other rights unless otherwise specified in this data sheet, and makes n o claim that the circuits are free from patent infringement. applications for any devices s hown in this data sheet are for illustration only a nd intersema makes no claim or warranty that such applications will be suitable fo r the use specified without further testing or modi fication.
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