Datasheet

MPX4250
Sensors
4 Freescale Semiconductor
Pressure
On-chip Temperature Compensation and Calibration
Figure 2 illustrates the differential/gauge pressure 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.
The MPX4250 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 3 shows the recommended decoupling circuit for
interfacing the output of the integrated sensor to the A/D input
of a microprocessor or microcontroller.
Figure 4 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 85°C using the decoupling circuit shown in Figure 3. The
output will saturate outside of the specified pressure range
.
Figure 2. Cross Sectional Diagram (not to scale)
Figure 3. Recommended Power Supply Decoupling and Output Filtering
(For additional output filtering, please refer to Application Note AN1535)
Figure 4. Output versus Absolute Pressure
Stainless Steel
Metal Cover
Epoxy Case
RTV Die Bond
P2
Lead Frame
Wire Bond
Die
P1
Fluoro Silicone
Die Coat
+5.1 V
1.0 μF
0.01 μF
470 pFGND
V
s
V
out
IPS
Output
Output (Volts)
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0
10 20 30 40 50 60 70 80 90
100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260
Pressure in kPa
TYP
MIN
MAX
Transfer Function:
V
out
= V
s
* (0.00369*P + 0.04) ± Error
V
S
= 5.1 Vdc
Temperature = 0 to 85°C