MPX2200 MPX2201 SERIES

3

Motorola Sensor Device Data

LINEARITY

Linearity refers to how well a transducer’s output follows

the equation: Vout = Voff + sensitivity x P over the operating

pressure range. There are two basic methods for calculating

nonlinearity: (1) end point straight line fit (see Figure 2) 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.

Figure 2. Linearity Specification Comparison

LEAST

SQUARE

DEVIATION

PRESSURE (% FULLSCALE)

0

50

100

END POINT

STRAIGHT LINE FIT

EXAGGERATED

PERFORMANCE

CURVE

LEAST SQUARES FIT

STRAIGHT LINE

DEVIATION

OFFSET

ON–CHIP TEMPERATURE COMPENSATION and CALIBRATION

Figure 3 shows the output characteristics of the MPX2200

series at 25

°C. The output is directly proportional to the dif-

ferential 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. Output versus Pressure Differential

Figure 4. Cross–Sectional Diagrams (Not to Scale)

40

35

30

25

20

15

10

5

0

–5

050

7.25

100

14.5

150

21.75

200

29

PRESSURE

SPAN

RANGE

(TYP)

OFFSET

kPa

PSI

VS = 10 Vdc

TA = 25°C

P1 > P2

25

75

125

175

MAX

TYP

MIN

SILICONE GEL

DIE COAT

WIRE BOND

LEAD FRAME

DIFFERENTIAL/GAUGE

DIE

STAINLESS STEEL

METAL COVER

EPOXY

CASE

DIFFERENTIAL/GAUGE ELEMENT

DIE

BOND

SILICONE GEL

DIE COAT

WIRE BOND

LEAD FRAME

ABSOLUTE

DIE

STAINLESS STEEL

METAL COVER

EPOXY

CASE

DIE

BOND

ABSOLUTE ELEMENT

P1

P2

P1

P2

Figure 4 illustrates an absolute sensing die (right) and the

differential or gauge die 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 sig-

nal to be transmitted to the silicon diaphragm.

The MPX2200 series pressure sensor operating charac-

teristics 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 perfor-

mance and long term reliability. Contact the factory for in-

formation regarding media compatibility in your application.