Motorola MPX700GVSX, MPX700GS, MPX700DP, MPX700ASX, MPX700AP Datasheet
...
SEMICONDUCTOR TECHNICAL DATA
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by MPX700/D
The MPX700 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
• Linearity to ± 0.5% (Max) Linearity
• Easy to Use Chip Carrier Package Options
• Ratiometric to Supply Voltage
• 60 mV Span (Typ)
• Absolute, Differential and Gauge Options
Application Examples
• Environmental Control Systems
• Pneumatic Control Systems
• Appliances
• Automotive Performance Controls
• Medical Instrumentation
• Industrial Controls
Figure 1 illustrates a schematic of the internal circuitry on the stand–alone pressure
sensor chip.
PIN 3
+ V
S
PIN 2
+ V
PIN 4
– V
out
out
X–ducer
0 to 700 kPa (0–100 psi)
60 mV FULL SCALE SPAN
(TYPICAL)
BASIC CHIP
CARRIER ELEMENT
CASE 344–15, STYLE 1
DIFFERENTIAL
PORT OPTION
CASE 344C–01, STYLE 1
NOTE: Pin 1 is the notched pin.
PIN NUMBER
1
Gnd
2
+V
out
3
V
4
–V
S
out
PIN 1
Figure 1. Uncompensated Pressure Sensor Schematic
VOLTAGE OUTPUT versus APPLIED DIFFERENTIAL PRESSURE
The differential voltage output of the X–ducer is directly proportional to the differential
pressure applied.
The absolute sensor has a built–in reference vacuum. The output voltage will decrease
as vacuum, relative to ambient, is drawn on the pressure (P1) side.
The output voltage of the differential or gauge sensor increases with increasing
pressure applied to the pressure (P1) side relative to the vacuum (P2) side. Similarly,
output voltage increases as increasing vacuum is applied to the vacuum (P2) side
relative to the pressure (P1) side. This sensor is designed for applications where P1 is
always greater than, or equal to P2.
Senseon and X–ducer are trademarks of Motorola, Inc.
REV 5
Motorola, Inc. 1997
1Motorola Sensor Device Data
MAXIMUM RATINGS
Rating Symbol Value Unit
(4)
(8)
(P2 v 1 Atmosphere) P1
(8)
(P2 v 1 Atmosphere) P1
= 3.0 Vdc, TA = 25°C unless otherwise noted. P1 w P2; P2 v1 Atmosphere.)
S
Characteristic
(1)
(2)
(3)
(5)
(5)
(0 to 700 kPa) — — ± 0.1 — %V
(5)
(–40°C to +125°C) — — ± 0.5 — %V
(5)
(5)
(5)
(6)
(10% to 90%) t
(7)
MPX700D
MPX700A
max
burst
stg
A
Symbol Min Typ Max Unit
P
OP
V
S
o
V
FSS
V
off
— –0.5
TCV
FSS
TCV
off
TCR 0.34 — 0.4 %Zin/°C
in
out
R
— — 20 — ms
–1.0
–0.21 — –0.15 %V
400 — 550 Ω
750 — 1800 Ω
2800 kPa
5000 kPa
–40 to +125 °C
–40 to +125 °C
0 — 700 kPa
— 3.0 6.0 Vdc
— 6.0 — mAdc
45 60 90 mV
0 20 35 mV
—
—
— ±15 — µV/°C
— 1.0 — ms
0.5
1.0
%V
Overpressure
Burst Pressure
Storage Temperature T
Operating Temperature T
OPERATING CHARACTERISTICS (V
Pressure Range
Supply Voltage
Supply Current I
Full Scale Span
Offset
Sensitivity ∆V/∆P — 86 — µV/kPa
Linearity
Pressure Hysteresis
Temperature Hysteresis
Temperature Coefficient of Full Scale Span
Temperature Coefficient of Offset
Temperature Coefficient of Resistance
Input Impedance Z
Output Impedance Z
Response Time
Warm–Up
FSS
FSS
FSS
FSS
/°C
MECHANICAL CHARACTERISTICS
Characteristic Symbol Min Typ Max Unit
Weight (Basic Element, Case 344–15) — — 2.0 — Grams
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 self–heating.
3. Full Scale Span (V
minimum rated pressure.
4. Offset (V
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
• Temperature Hysteresis: Output deviation at any temperature within the operating temperature range, after the temperature is
• Pressure Hysteresis: Output deviation at any pressure within the specified range, when this pressure is cycled to and from the
• 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
• TCR: Zin deviation with minimum rated pressure applied, over the temperature range of –40°C to +125°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. Warm–up is defined as the time required for the device to meet the specified output voltage after the pressure has been stabilized.
8. Basic Element only, Case 344–15.
9. P2 max : 500 kPa.
) is defined as the output voltage at the minimum rated pressure.
off
) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the
FSS
pressure range.
cycled to and from the minimum or maximum operating temperature points, with zero differential pressure
applied.
minimum or maximum rated pressure, at 25°C.
to 25°C.
relative to 25°C.
2 Motorola Sensor Device Data
TEMPERATURE COMPENSATION
Figure 2 shows the typical output characteristics of the
MPX700 series over temperature.
The X–ducer piezoresistive pressure sensor element is a
semiconductor device which gives an electrical output signal
proportional to the pressure applied to the device. This device uses a unique transverse voltage diffused semiconductor 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 differences 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 MPX2700 series
sensors.
Several approaches to external temperature compensation 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: V
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 calculations 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.
out
= V
+ sensitivity x P over the operating
off
80
70
60
50
40
30
OUTPUT (mVdc)
20
10
0
0
kPa
MPX700
VS = 3 Vdc
P1 > P2
20
40
PRESSURE DIFFERENTIAL
–40°C
+125°C
60PSI
+25°C
SPAN
RANGE
(TYP)
OFFSET
(TYP)
10080
700560420280140
70
LINEARITY
50
40
30
OUTPUT (mVdc)
20
10
0
0 MAX
ACTUAL
THEORETICAL
PRESSURE (kPA)
Figure 2. Output versus Pressure Differential Figure 3. Linearity Specification Comparison
SILICONE GEL
DIE COAT
WIRE BOND
DIFFERENTIAL/GAUGE
DIE
P1
STAINLESS STEEL
METAL COVER
EPOXY
CASE
WIRE BOND
SILICONE GEL
DIE COAT
ABSOLUTE
DIE
P1
SPAN
(V
)
FSS
OFFSET
(V
)
OFF
P
OP
STAINLESS STEEL
METAL COVER
EPOXY
CASE
LEAD FRAME
DIFFERENTIAL/GAUGE ELEMENT
P2
DIE
BOND
Figure 4. Cross–Sectional Diagrams (not to scale)
Figure 4 illustrates the differential or gauge configuration
in the basic chip carrier (Case 344–15). A silicone gel isolates the die surface and wire bonds from the environment,
while allowing the pressure signal to be transmitted to the silicon diaphragm.
The MPX700 series pressure sensor operating character-
LEAD FRAME
ABSOLUTE ELEMENT
P2
DIE
BOND
istics 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 regarding media compatibility in your application.
3Motorola Sensor Device Data
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