9.2.1.2 Detailed Design Procedure

The bridge sensor signal flow model is shown in Figure 9-2.

Figure 9-2. Bridge Sensor Signal Flow Model

The bridge sensor is modeled as a multiplier, with inputs from an excitation voltage and pressure sensor

producing an output voltage given in Equation 1:

bridge

exc

exc

p

V

(P,V

)

V

K (P)

u

(1)

the range of the sensor, normalized to a scale from 0 to 1. Solving this equation with the variables given in the

OS

ref

p

out

lin

p

V

V

G K (P)

V

(P)

1 G K

K (P)

u

u

u

u

(2)

values, the system can be linearized.

v

ref

lin

out _ high

out _ low

v

out _ high

out _ low

4 B

V

K

(V

V

) 2 B

(V

V

)

u

u

u

u

(3)

p

p

p

v

p

p

K (1) K (0)

K (0.5)

2

B

K (1) K (0)

(4)

gain is calculated using Equation 5 and Equation 6.

OS

ref

p

out _ high

lin

p

V

V

G K (1)

V

1 G K

K (1)

u

u

u

u

(5)

OS

ref

p

out _ high

lin

p

V

V

G K (0)

V

1 G K

K (0)

u

u

u

u

(6)

OPA182, OPA2182, OPA4182

SBOS936D – DECEMBER 2019 – REVISED DECEMBER 2021

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