1
Motorola Sensor Device Data
10 kPa
Uncompensated
Silicon Pressure Sensors
The MPX12 series device is a silicon piezoresistive pressure sensor providing a very
accurate and linear voltage output -- directly proportional to the applied pressure. This
standard, low cost, uncompensated sensor permits manufacturers to design and add
their own external temperature compensating and signal conditioning networks.
Compensation techniques are simplified because of the predictability of Motorola's single
element strain gauge design.
Features
Low Cost
Patented Silicon Shear Stress Strain Gauge Design
Ratiometric to Supply Voltage
Easy to Use Chip Carrier Package Options
Differential and Gauge Options
Application Examples
Air Movement Control
Environmental Control Systems
Level Indicators
Leak Detection
Medical Instrumentation
Industrial Controls
Pneumatic Control Systems
Robotics
Figure 1 shows a schematic of the internal circuitry on the standalone pressure
sensor chip.
Figure 1. Uncompensated Pressure Sensor Schematic
PIN 3
Xducer
PIN 2
PIN 4
+ Vout
Vout
+ VS
PIN 1
VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the Xducer is directly proportional to the differential
pressure applied.
The output voltage of the differential or gauge sensor increases with increasing
pressure applied to the pressure side (P1) relative to the vacuum side (P2). Similarly,
output voltage increases as increasing vacuum is applied to the vacuum side (P2)
relative to the pressure side (P1).
Senseon and Xducer are trademarks of Motorola, Inc.
Order this document
by MPX12/D
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Motorola, Inc. 1997
MPX12
SERIES
0 to 10 kPa (0 1.45 psi)
35 mV FULL SCALE SPAN
(TYPICAL)
NOTE: Pin 1 is the notched pin.
PIN NUMBER
BASIC CHIP
CARRIER ELEMENT
CASE 34415, STYLE 1
DIFFERENTIAL
PORT OPTION
CASE 344C01, STYLE 1
1
2
Gnd
+Vout
3
4
VS
Vout
MPX12 SERIES
2
Motorola Sensor Device Data
MAXIMUM RATINGS
Rating
Symbol
Value
Unit
Overpressure(8) (P1 > P2)
Pmax
75
kPa
Burst Pressure(8) (P1 > P2)
Pburst
100
kPa
Storage Temperature
Tstg
40 to +125
C
Operating Temperature
TA
40 to +125
C
OPERATING CHARACTERISTICS
(VS = 3.0 Vdc, TA = 25
C unless otherwise noted, P1 > P2)
Characteristic
Symbol
Min
Typ
Max
Unit
Differential Pressure Range(1)
POP
0
--
10
kPa
Supply Voltage(2)
VS
--
3.0
6.0
Vdc
Supply Current
Io
--
6.0
--
mAdc
Full Scale Span(3)
VFSS
45
55
70
mV
Offset(4)
Voff
0
20
35
mV
Sensitivity
V/
P
--
5.5
--
mV/kPa
Linearity(5)
--
0.5
--
5.0
%VFSS
Pressure Hysteresis(5) (0 to 10 kPa)
--
--
0.1
--
%VFSS
Temperature Hysteresis(5) ( 40
C to +125
C)
--
--
0.5
--
%VFSS
Temperature Coefficient of Full Scale Span(5)
TCVFSS
0.22
--
0.16
%VFSS/
C
Temperature Coefficient of Offset(5)
TCVoff
--
15
--
V/
C
Temperature Coefficient of Resistance(5)
TCR
0.21
--
0.27
%Zin/
C
Input Impedance
Zin
400
--
550
Output Impedance
Zout
750
--
1250
Response Time(6) (10% to 90%)
tR
--
1.0
--
ms
WarmUp
--
--
20
--
ms
Offset Stability(9)
--
--
0.5
--
%VFSS
MECHANICAL CHARACTERISTICS
Characteristic
Symbol
Min
Typ
Max
Unit
Weight (Basic Element, Case 34415)
--
--
2.0
--
Grams
Common Mode Line Pressure(7)
--
--
--
690
kPa
NOTES:
1. 1.0 kPa (kiloPascal) equals 0.145 psi.
2. Device is ratiometric within this specified excitation range. Operating the device above the specified excitation range may induce additional
error due to device selfheating.
3. Full Scale Span (VFSS) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
minimum rated pressure.
4. Offset (Voff) is defined as the output voltage at the minimum rated pressure.
5. Accuracy (error budget) consists of the following:
Linearity:
Output deviation from a straight line relationship with pressure, using end point method, over the specified
pressure range.
Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
Pressure Hysteresis:
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.
TcSpan:
Output deviation at full rated pressure over the temperature range of 0 to 85
C, relative to 25
C.
TcOffset:
Output deviation with minimum rated pressure applied, over the temperature range of 0 to 85
C, relative
to 25
C.
TCR:
Zin deviation with minimum rated pressure applied, over the temperature range of 40
C to +125
C,
relative to 25
C.
6. Response Time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when subjected to
a specified step change in pressure.
7. Common mode pressures beyond specified may result in leakage at the casetolead interface.
8. Exposure beyond these limits may cause permanent damage or degradation to the device.
9. Offset stability is the product's output deviation when subjected to 1000 hours of Pulsed Pressure, Temperature Cycling with Bias Test.
MPX12 SERIES
3
Motorola Sensor Device Data
TEMPERATURE COMPENSATION
Figure 2 shows the typical output characteristics of the
MPX12 series over temperature.
The Xducer piezoresistive pressure sensor element is a
semiconductor device which gives an electrical output signal
proportional to the pressure applied to the device. This de-
vice uses a unique transverse voltage diffused semiconduc-
tor strain gauge which is sensitive to stresses produced in a
thin silicon diaphragm by the applied pressure.
Because this strain gauge is an integral part of the silicon
diaphragm, there are no temperature effects due to differ-
ences in the thermal expansion of the strain gauge and the
diaphragm, as are often encountered in bonded strain gauge
pressure sensors. However, the properties of the strain
gauge itself are temperature dependent, requiring that the
device be temperature compensated if it is to be used over
an extensive temperature range.
Temperature compensation and offset calibration can be
achieved rather simply with additional resistive components,
or by designing your system using the MPX2010D series
sensor.
Several approaches to external temperature compensa-
tion over both 40 to +125
C and 0 to + 80
C ranges are
presented in Motorola Applications Note AN840.
LINEARITY
Linearity refers to how well a transducer's output follows
the equation: Vout = Voff + sensitivity x P over the operating
pressure range (Figure 3). There are two basic methods for
calculating nonlinearity: (1) end point straight line fit or (2) a
least squares best line fit. While a least squares fit gives the
"best case" linearity error (lower numerical value), the cal-
culations required are burdensome.
Conversely, an end point fit will give the "worst case" error
(often more desirable in error budget calculations) and the
calculations are more straightforward for the user. Motorola's
specified pressure sensor linearities are based on the end
point straight line method measured at the midrange
pressure.
Figure 2. Output versus Pressure Differential
Figure 3. Linearity Specification Comparison
Figure 4. CrossSectional Diagram (not to scale)
SILICONE
DIE COAT
WIRE BOND
LEAD FRAME
DIE
STAINLESS STEEL
METAL COVER
EPOXY
CASE
RTV DIE
BOND
P1
P2
OFFSET
(VOFF)
70
OUTPUT
(mVdc)
60
50
40
30
20
10
0
0
MAX
POP
SPAN
(VFSS)
PRESSURE (kPA)
ACTUAL
THEORETICAL
LINEARITY
PRESSURE DIFFERENTIAL
OUTPUT
(mVdc)
80
70
60
50
40
30
20
10
0
0
0.3
2.0
0.6
4.0
0.9
6.0
1.2
8.0
10
1.5
PSI
kPa
SPAN
RANGE
(TYP)
OFFSET
(TYP)
VS = 3 Vdc
P1 > P2
40
C
+ 25
C
+ 125
C
Figure 4 illustrates the differential or gauge configuration
in the basic chip carrier (Case 34415). A silicone gel iso-
lates the die surface and wire bonds from the environment,
while allowing the pressure signal to be transmitted to the sil-
icon diaphragm.
The MPX12 series pressure sensor operating characteris-
tics and internal reliability and qualification tests are based
on use of dry air as the pressure media. Media other than dry
air may have adverse effects on sensor performance and
long term reliability. Contact the factory for information re-
garding media compatibility in your application.
MPX12 SERIES
4
Motorola Sensor Device Data
PRESSURE (P1)/VACUUM (P2) SIDE IDENTIFICATION TABLE
Motorola designates the two sides of the pressure sensor
as the Pressure (P1) side and the Vacuum (P2) side. The
Pressure (P1) side is the side containing silicone gel which
isolates the die from the environment. The Motorola MPX
pressure sensor is designed to operate with positive differen-
tial pressure applied, P1 > P2.
The Pressure (P1) side may be identified by using the table
below:
Part Number
Case Type
Pressure (P1) Side Identifier
MPX12D
34415
C
Stainless Steel Cap
MPX12DP
344C01
Side with Part Marking
MPX12GP
344B01
Side with Port Attached
MPX12GS
344E01
Side with Port Attached
MPX12GSX
344F01
Side with Port Attached
ORDERING INFORMATION
MPX12 series pressure sensors are available in differential and gauge configurations. Devices are available in the basic
element package or with pressure port fittings which provide printed circuit board mounting ease and barbed hose pressure
connections.
D
i
T
O
i
C
T
MPX Series
Device Type
Options
Case Type
Order Number
Device Marking
Basic Element
Differential
Case 34415
MPX12D
MPX12D
Ported Elements
Differential
Case 344C01
MPX12DP
MPX12DP
Gauge
Case 344B01
MPX12GP
MPX12GP
Gauge Stove Pipe
Case 344E01
MPX12GS
MPX12D
Gauge Axial
Case 344F01
MPX12GSX
MPX12D
MPX12 SERIES
5
Motorola Sensor Device Data
PACKAGE DIMENSIONS
CASE 34415
ISSUE W
STYLE 1:
PIN 1. GROUND
2. + OUTPUT
3. + SUPPLY
4. OUTPUT
M
A
M
0.136 (0.005)
T
1
2
3
4
PIN 1
R
N
L
G
F
D
4 PL
SEATING
PLANE
T
C
M
J
B
A
DIM
MIN
MAX
MIN
MAX
MILLIMETERS
INCHES
A
0.595
0.630
15.11
16.00
B
0.514
0.534
13.06
13.56
C
0.200
0.220
5.08
5.59
D
0.016
0.020
0.41
0.51
F
0.048
0.064
1.22
1.63
G
0.100 BSC
2.54 BSC
J
0.014
0.016
0.36
0.40
L
0.695
0.725
17.65
18.42
M
30 NOM
30 NOM
N
0.475
0.495
12.07
12.57
R
0.430
0.450
10.92
11.43
_
_
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME
Y14.5M, 1994.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION A IS INCLUSIVE OF THE MOLD
STOP RING. MOLD STOP RING NOT TO EXCEED
16.00 (0.630).
POSITIVE
PRESSURE (P1)
POSITIVE
PRESSURE
(P1)
STYLE 1:
PIN 1. GROUND
2. + OUTPUT
3. + SUPPLY
4. OUTPUT
CASE 344B01
ISSUE B
SEATING
PLANE
B
N
R
C
J
T
D
F
U
H
L
PORT #1
POSITIVE
PRESSURE
PIN 1
A
Q
S
K
G
4 PL
P
S
Q
M
0.25 (0.010)
T
S
S
M
0.13 (0.005)
Q
S
T
1 2
3 4
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5, 1982.
2. CONTROLLING DIMENSION: INCH.
DIM
MIN
MAX
MIN
MAX
MILLIMETERS
INCHES
A
1.145
1.175
29.08
29.85
B
0.685
0.715
17.40
18.16
C
0.305
0.325
7.75
8.26
D
0.016
0.020
0.41
0.51
F
0.048
0.064
1.22
1.63
G
0.100 BSC
2.54 BSC
H
0.182
0.194
4.62
4.93
J
0.014
0.016
0.36
0.41
K
0.695
0.725
17.65
18.42
L
0.290
0.300
7.37
7.62
N
0.420
0.440
10.67
11.18
P
0.153
0.159
3.89
4.04
Q
0.153
0.159
3.89
4.04
R
0.230
0.250
5.84
6.35
S
U
0.910 BSC
23.11 BSC
0.220
0.240
5.59
6.10
(P1)
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