AN420

Example

Doc ID 2078 Rev 2

9/15

Figure 3.

Conversion routine

The actual circuit values are calculated as follows. With arbitrarily chosen Rr equal to 10 K

Ω,

the other resistor values are given by:

VN1 = VN2 = VN3 = 0

CONVERT

SATURATED?

NO

DONE

Vin => [0, 2.5] V

CONVERT

VN3 = 1

YES

SATURATED?

NO

DONE

Vin => [2.5, 5] V

CONVERT

YES

SATURATED?

NO

DONE

VN3 = 0, VN2 = 1

Vin => [5, 7.5] V

YES

CONVERT

VN2 = 0, VN1 = 1

DONE

Vin => [7.5, 10] V

R

r

R

P1

----------

2R

P1

⇒

5000

Ω

==

R

r

R

N1

----------

3R

N1

⇒

3333

Ω

==

R

r

R

N2

----------

2R

N2

⇒

5000

Ω

==