MPX4105 SERIES

3

Motorola Sensor Device Data

µ PROCESSOR

A/D

51 k

50 pF

MPX4105A

OUTPUT

(PIN 1)

SILICONE

DIE COAT

WIRE BOND

LEAD FRAME

DIE

STAINLESS STEEL

METAL COVER

EPOXY

CASE

RTV DIE

BOND

SEALED VACUUM REFERENCE

P1

P2

Figure 2. Cross–Sectional Diagram

(Not to Scale)

Figure 3. Typical Decoupling Filter for Sensor to

Microprocessor Interface

Figure 2 illustrates 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 dia-

phragm. The MPX4105 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 per-

formance and long–term reliability. Contact the factory for in-

formation regarding media compatibility in your application.

Figure 3 shows a typical decoupling circuit for interfacing

the integrated MAP sensor to the A/D input of a microproces-

sor. Proper decoupling of the power supply is recommended.

Figure 4 shows the sensor output signal relative to pres-

sure input. Typical, minimum, and maximum output curves

are shown for operation over a temperature range of 0

° to

85

°C. (The output will saturate outside of the specified pres-

sure range.)

5.0

4.5

4.0

3.5

3.0

Pressure (ref: to sealed vacuum) in kPa

MAX

MIN

2.5

2.0

1.5

1.0

0.5

0

Figure 4. Output versus Absolute Pressure

TEMP = 0 to 85

°C

15 kPA TO 105 kPA

MPX4105A

TRANSFER FUNCTION:

Vout = Vs* (0.01*P–0.09) ± Error

VS = 5.1 Vdc

TYP