Pressure sensors

C28 series

Absolute pressure sensor die

AS SEN PD

2009-08-03

Please read

Cautions and warnings and

Page 5 of 8

Important notes at the end of this document.

Symbols and Terms

1)

This is the maximal allowed voltage, which may be applied to the piezoresistive bridge circuit without damage.

2)

conditions like gluing, wire bonding etc, the die has to be tested over the operating temperature range by the customer

fully assembled. For design verification and process control samples, mounted on a TO39 base are tested over a

3)

will not affect the performance of the pressure sensor dies.

4)

5)

6)

tested at room temperature on wire bonded samples by applying the specified burst pressure for 10 minutes.

The evaluation of this test is done by measuring the bridge resistance or by optical inspection of the diaphragm.

7)

coefficient of the offset voltage are defined by:

(

)

]

V

[

5

V

])

V

[

5

(

r

V

r

DD

8)

The total bridge resistance is defined between pad X5 and X2, X3 (see the dimensional drawing in this data sheet) of the

closed piezoresistive bridge circuit. The total bridge resistance is in a good approximation the output impedance of the

piezoresistive bridge circuit. This parameter is tested completely on a wafer (wafer level test measurement).

9)

Temperature coefficients of resistance α

α

α

β

β

The temperature coefficients of resistance are tested for design verification on samples, mounted on a TO39 base

The temperature coefficients of first and second order are defined with the polynomial:

(

)

(











°

−

β

+

°

−

α

+

°

=

=

2

Rs

Rs

S

S

C

25

T

C

25

T

1

)

C

25

T

(

R

)

T

(

R

0

to zero bar. It should be noted that this parameter may be influenced by the assembly.

0

These parameters strongly depend on assembly conditions like gluing, wire bonding etc.

The temperature coefficients of offset voltage are tested for design verification on samples, mounted on a TO39 base

(

) (

2

1

o

2

s

s

0

)

C

25

T

(

v

)

C

25

T

(

v

)

C

25

(

V

)

C

25

T

(

)

C

25

T

(

1

)

T

(

V

°

−

+

°

−

+

°

°

−

β

+

°

−

α

+

=