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 pressure sensor for harsh environment. A vacuum reference
cavity is sealed on top of the sensitive silicon membrane by the anodic bonding of a Pyrex™ cap. The pressure,
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™ is bonded on the backside. As the pressure port consists of
Pyrex™ and silicon, both stable in most of the chemicals, the MS7228 is suitable for media-resistive
applications.
FEATURES
•
•
•
Media resistive pressure sensor die
Output Span 150mV @ 5 V
Temperature Range -40°
…+125°
C
•
•
•
Linearity 0.05% (typical)
Die Size 1.63 x 1.95 mm
2
Low Cost, High reliability
APPLICATION
•
•
•
Harsh environments
Absolute pressure sensor systems
Braking systems
•
•
•
Tire pressure
Engine controls
Diving computers
ELECTRICAL CONNECTIONS
Positive output for pressure applied backside
Vs+ : Supply voltage of Wheatstone bridge
Epi : Connection of epitaxial layer (membrane)
Out- : Negative output
Out+ : Positive output
GND1 : Ground
GND2 : Ground
GND1
1
Vs+
EPI
Out+
Out-
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).
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PAD OUT
MS7228
Out-
Vs+
Important 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+).
The epitaxial layer is connected to the Vs+ pin on the die.
GND1
Epi
GND2
Out+
LAYOUT
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FULL SCALE PRESSURE
kPa
2800
bar
28
mbar
28000
PSI
406
atm
27.5
mm Hg
21002
m H
2
O
285
Inches H
2
O
11242
ABSOLUTE MAXIMUM RATINGS
Parameter
Supply voltage
Storage temperature
Pressure overload
Symbol
VS+
T
S
Ta = 25 C
-40
o
Conditions
Min
Max
20
+150
70
Unit
V
C
Bar
o
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
100
-40
Typ
Max
28
125
Unit
Bar
°
C
kΩ
mV
mV
% FS
ppm/°
C
ppm/°
C
µV/°
C
% FS
% FS
% FS
1
2
Notes
3.4
130
0
± 0.05
3.8
160
40
± 0.15
+ 3300
- 2300
+ 80
± 0.15
± 0.15
0.3
+ 2400
- 1500
- 80
+ 2800
- 1900
± 0.05
± 0.05
3
4
5
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 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.
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PICKING TOOLS
The MS7228 sensors have a topside Pyrex™ cap (1.23 x 1.02 mm ) and a backside Pyrex™ (1.95 x 1.63 mm ).
The pick and place tool has to be of a soft material 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
External dimension
Internal dimensions
RTR-A1-060x060
TL & TW: 0.06 inch /1.52 mm
∅H:
0.035 inch / 0.89 mm
2
2
WIRE BONDING
The bondable area is 100 x 100
µm
. 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.
2
ORDERING INFORMATION
Product Code
MS7228-A
type
Absolute
Product
28 bar Pressure Sensors sawn on b/f
Art.-Nr.
722825021
The MS7228 dice are supplied sawn on blue foil, mounted on plastic rings
FACTORY CONTACTS
Intersema Sensoric SA
Ch. Chapons-des-Prés 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 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.
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