DA6505.005

11 June 2018

38 (44)

APPLICATION INFORMATION

Table 17 shows an example of calculated minimum and maximum differential signal values at the sensor input

based on both full and linear input signal ranges of the ADC using the equations 3, 4, 7 and 8. The table shows

input signal values at all eight offset options at both offset polarity signs. The table values are for unity gain

amplification setting (GAIN=1). The input signal values for other gain settings can be easily calculated simply by

dividing these values by the other gain setting value.

Table 17. Min and max input signal values in overall and linear input signal ranges for GAIN=1 setting

OFS%

[% of ISRADC]

[mV]

[mV]

[mV]

[mV]

-49 %

-1386

14

-1246

-126

-42 %

-1288

112

-1148

-28

-35 %

-1190

210

-1050

70

-28 %

-1092

308

-952

168

-21 %

-994

406

-854

266

-14 %

-896

504

-756

364

-7 %

-798

602

-658

462

0 %

-700

700

-560

560

7 %

-602

798

-462

658

14 %

-504

896

-364

756

21 %

-406

994

-266

854

28 %

-308

1092

-168

952

35 %

-210

1190

-70

1050

42 %

-112

1288

28

1148

49 %

-14.0

1386.0

126.0

1246.0

Pressure Measurement Configuration

A piezoresistive absolute pressure sensor can be modeled roughly with the following signal voltage characteristic

when including only first order pressure and temperature characteristics.

(

)

(

)

(

)

(

)

(











−



+



+



−



+





=

REF

OS

FS

REF

FS

REF

IN

T

T

TC

OS

p

p

T

T

TC

FS

VDD

VDDS

T

p

V

1

1

,

Equation 16

VDDS = sensor supply voltage; 1.68V typ

sensor parameters (FS, OS) have been specified

(often 5V)

p = pressure [bar]

FS = full-scale span [V]

OS = zero pressure offset [V]

[ppm/

C]

C]

C]

T = actual temperature to be measured [

C]

The above linear approximation includes sensor full-scale span and offset signal temperature dependencies.