MPX2053

Sensors

4

Freescale Semiconductor

ON-CHIP TEMPERATURE COMPENSATION AND CALIBRATION

Figure 2. Output vs. Pressure Differential

Figure 2 shows the output characteristics of the MPX2053/

MPXV2053G series at 25°C. The output is directly

proportional to the differential pressure and is essentially a

straight line.

The effects of temperature on full scale span and offset are

very small and are shown under Operating Characteristics.

Figure 3. Unibody Package: Cross Sectional Diagram (Not to Scale)

Figure 3 illustrates the differential/gauge die in the basic

chip carrier (Case 344). 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 MPX2053/MPXV2053G 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.

LINEARITY

Linearity refers to how well a transducer's output follows

pressure range. There are two basic methods for calculating

nonlinearity: (1) end point straight line fit (see Figure 4) 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.

Freescale’s specified pressure sensor linearities are based

on the end point straight line method measured at the

midrange pressure.

Figure 4. Linearity Specification Comparison

MPX2053

P1 > P2

Span

Range

(Typical)

MAX

TYP

MIN

Offset

(Typical)

kPa

PSI

40

35

30

25

20

15

5

0

10

–5

12.5

25

37.5

50

0

1.8

3.6

5.4

7.25

Silicone

Die Coat

Die

P1

P2

Wire Bond

Lead Frame

RTV Die

Bond

Epoxy

Case

Stainless Steel

Metal Cover

Least

Square

Deviation

Pressure (% Full Scale)

0

50

100

End Point Straight

Line Fit

Exaggerated

Performance

Curve

Least Squares Fit

Straight Line

Deviation

Offset