MPX5700
Sensors
4 Freescale Semiconductor, Inc.
Pressure
On-chip Temperature Compensation and Calibration
Figure 3. illustrates both the Differential/Gauge and the
Absolute Sensing Chip in the basic chip carrier (Case 867).
A fluorosilicone gel isolates the die surface and wire bonds
from the environment, while allowing the pressure signal to
be transmitted to the sensor diaphragm. (For use of the
MPX5700D in a high-pressure cyclic application, consult the
factory.)
The MPX5700 series pressure sensor operating
characteristics, 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.
Figure 2. shows the sensor output signal relative to
pressure input. Typical, minimum, and maximum output
curves are shown for operation over a temperature range of
0 to 85C using the decoupling circuit shown in . The output
will saturate outside of the specified pressure range.
shows the recommended decoupling circuit for interfacing
the output of the integrated sensor to the A/D input of a
microprocessor or microcontroller. Proper decoupling of the
power supply is recommended.
Figure 2. Output vs. Pressure Differential
Figure 3. Cross-Sectional Diagrams (not to scale)
Figure 4. Recommended Power Supply Decoupling and Output Filtering
(For additional output filtering, please refer to Application Note AN1646)
Differential Pressure (kPa)
Output (V)
Typical
Minimum
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0
100
200
300
400
600500
Maximum
700 800
Transfer Function:
V
out
= V
S
*(0.0012858*P+0.04) ± Error
V
S
= 5.0 Vdc
Temperature = 0 to 85
°C
Fluoro Silicone
Die Coat
Wire Bond
Die
P1
Stainless Steel
Metal Cover
Lead Frame
RTV Die
Bond
Epoxy Case
P2
Fluoro Silicone
Die Coat
Wire Bond
Die
P1
Stainless Steel
Metal Cover
Lead Frame
RTV Die
Bond
Epoxy Case
P2
ABSOLUTE ELEMENTDIFFERENTIAL/GAUGE ELEMENT
+5 V
1.0 F
0.01 F
470 pFGND
V
s
V
out
IPS
Output
