DA6502.008

29 November 2012

15 (20)

APPLICATION INFORMATION

Temperature Measurement Configuration

resistor bridge configuration together with four internal resistors R1, R2, R3 and R4. See figure 5.

Figure 5. Temperature Measurement Configuration

In the temperature measurement configuration the A/D converter input signal has the following characteristics.

( )

(

)

[

]

(

)

[

]

























+

+

−

⋅

+

⋅

−

⋅

+

⋅

−

+

⋅

=

1

1

1

1

1

1

4

3

4

2

1

R

R

T

T

TC

R

T

T

TC

R

R

R

VDD

T

V

REF

R

REF

S

S

IN

Equation 5.

VDD = supply voltage

T = actual temperature to be measured [°C]

From equation 5 we get that the temperature signal has a rising temperature dependency vs. temperature when

illustration in figure 6.

Figure 5. Temperature signal dependency of sensor resistance temperature coefficient

GND

R2

R4

R1

R3

PI

NI

VDD