MS7970-D

MS7970 PRESSURE SENSOR DIE (0-70 BAR) • • • • 0 to 7000 kPa range (70 bar or 1015 PSI) Absolute/differential pressure sensors High linearity, small size RoHS-compatible & Pb-free1 DESCRIPTION The sensor element of the MS7970 consists of a silicon micro-machined membrane. Implanted resistors make use of the piezo-resistive effect to sense the membrane deflection and transform it in an electrical signal. This sensor, which has outstanding linearity and span values, is available in various configurations. The absolute pressure sensor employs a sealed vacuum reference cavity underneath the membrane. The Pyrex glass wafer used for this sealing has a thickness of 0.2 mm (MS7970-A_0.2) or 0.5 mm (MS7970-A_0.5). There are two gauge versions available: one with a drilled Pyrex glass (MS7970-D) and the other without Pyrex glass (MS7970-S). FEATURES • • • Uncompensated pressure sensor die Output span 310mV @ 5V Temperature range -40° …+125° C • • • Linearity 0.25% (typical) Very small die size 1.72 x 1.58 mm (MS7970-A) Low cost, high reliability APPLICATION • • Absolute pressure sensor systems Differential/gauge pressure sensor systems • • Engine controls Dive computers ELECTRICAL CONNECTIONS Positive output for pressure applied topside Vs+ EPI Vs+ : Supply voltage of Wheatstone bridge Epi : Connection of epitaxial layer (membrane) Out+ OutOut- : Negative output Out+ : Positive output GND1 : Ground GND2 : Ground GND1 1 GND2 The European RoHS directive 2002/95/EC (Restriction of the use of certain Hazardous Substances in electrical and electronic equipment) bans the use of lead, mercury, cadmium, hexavalent chromium and polybrominated biphenyls (PBB) or polybrominated diphenyl ethers (PBDE). DA7970_000.doc 000079701592 ECN 1205 May 11, 2009 1/5 BOND PAD CONFIGURATION Vs+ Epi OutImportant remarks: As the sensing elements are diffused resistances, the voltage applied on the ground pads (GND1 and GND2) has to be lower than the voltage applied on supply voltage pad (Vs+). MS7912 The epitaxial layer is connected to the Vs+ pin under the pad. Gold ball bonding or aluminium wedge bonding can be used to wire-bond the sensor. The quality of the wire-bonding is equipment and process dependant. For this reason, it is strongly recommended that a thorough wire-bonding qualification is made by the end user if the sensor is going to be operated over an extended temperature range. Out+ GND1 GND2 LAYOUT (Absolute sensors) MS7970-A_0.2 MS7970-A_0.5 Pad opening in passivation is 100 µm DA7970_000.doc 000079701592 ECN 1205 May 11, 2009 2/5 LAYOUT (Gauge sensors) MS7970-D MS7970-S Pad opening in passivation is 100 µm FULL SCALE PRESSURE kPa 7000 bar 70 mbar 70000 PSI 1015.3 atm 69.1 mm Hg 52504 m H2O 714 Inches H2O 28102 ABSOLUTE MAXIMUM RATINGS Parameter Supply voltage Storage temperature Pressure overload Symbol VS+ TS Ta = 25 C -40 o Conditions Min Max 20 +150 180 Unit V C Bar o DA7970_000.doc 000079701592 ECN 1205 May 11, 2009 3/5 ELECTRICAL CHARACTERISTICS (Reference conditions: Supply Voltage VS+ = 5 Vdc; Ambient Temperature Ta = 25° ) C Parameter Operating Pressure Range Operating Temperature Range Bridge Resistance Full-scale span (FS) Zero Pressure Offset Linearity Temperature Coefficient of Resistance Span Offset Pressure Hysteresis Repeatability Temperature Hysteresis NOTES Min 0 -40 3.0 250 -40 Typ Max 70 125 Unit Bar ° C KΩ mV mV % FS ppm/° C ppm/° C µV/° C % FS % FS % FS Notes 3.4 310 0 ± 0.25 3.8 370 40 ± 0.50 + 3300 - 2300 + 80 ± 0.15 ± 0.2 0.3 1 2 + 2400 - 1500 - 80 + 2800 - 1900 ± 0.05 ± 0.1 3 4 5 1) Deviation at one half full-scale pressure from the least squares best line fit over pressure range (0 to 70 bar). 2) Slope of the endpoint straight line from 25° to 60° C C. 3) Output deviation at any pressure within the specified range, when this pressure is cycled to and from the minimum or maximum rated pressure, at 25° C. 4) Same as 3) after 10 pressure cycles. 5) Maximum difference in offset after one thermal cycle from -40° to +125° C C. PICKING TOOLS The MS7970 sensors have a sensitive membrane size of 0.5 x 0.5 mm and outer dimensions of 1.72 x 1.58 mm (MS7970-A_0.2, MS7970-A_0.5 and MS7970-D) and 1.75 x 1.61mm (MS7970-S). The pick and place tool has to be of a soft material such as rubber (Hardness 78-97 Shore A). Its external size must fit the sensor and the vacuum cavity must be as large as the membrane itself. Successful tests have been made with specific SPT tools, see SPT drawing and references below. Ensure that the ejection pins do not touch the membrane for gauge versions. SPT references External dimension Internal dimensions RTR-A1-060x060 TL & TW: 0.06 inch /1.52 mm ∅H: 0.035 inch / 0.89 mm DA7970_000.doc 000079701592 ECN 1205 May 11, 2009 4/5 ORDERING INFORMATION Product Code MS7970-A_0.2 MS7970-A_0.5 MS7970-D MS7970-S Type Absolute Absolute Differential Differential Product 70 bar Pressure Sensors 0.2 mm Pyrex sawn on b/f 70 bar Pressure Sensors 0.5 mm Pyrex sawn on b/f 70 bar Pressure Sensors sawn on b/f 70 bar Pressure Sensors no Pyrex sawn on b/f Art.-Nr. 797025022 797025021 797025121 797025221 The MS7970 dice are supplied sawn on blue foil, mounted on plastic rings. FACTORY AND SALES CONTACTS Factory and European Sales office Intersema Sensoric SA Ch. Chapons-des-Prés 11 CH-2022 Bevaix Switzerland Phone: +41 32 847 9550 Fax: +41 32 847 9569 e-mail: Website: www.intersema.ch USA Measurement Specialties Inc. 1000 Lucas Way Hampton, VA 23666 USA Phone: Fax: e-mail: Website: +1 800 555 1551 +1 757 766 4297 sales@meas-spec.com www.meas-spec.com ASIA Measurement Specialties (China), Ltd. F1.6-4D, Tian An Development Compound Shenzhen, China 518048 Phone: Fax: e-mail: Website: +86 755 8330 1004 +86 755 8330 6797 pfc.cs.asia@meas-spec.com www.meas-spec.com 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 circuits shown in this data sheet, conveys no license under any patent or other rights unless otherwise specified in this data sheet, and makes no claim that the circuits are free from patent infringement. Applications for any devices shown in this data sheet are for illustration only and Intersema makes no claim or warranty that such applications will be suitable for the use specified without further testing or modification. DA7970_000.doc 000079701592 ECN 1205 May 11, 2009 5/5