ANALOG KEYBOARD

5/15

Active Key

V (Rxmin-Rpmax)

V (Rxmax-Rpmin)

V

hex.

dec.

V

hex.

dec.

S0

0.00

00

0

0.00

00

0

S1

0.48

18

24

0.51

1A

26

S2

0.94

30

48

1.00

33

51

S3

1.44

49

73

1.52

4E

78

S4

1.94

63

99

2.04

68

104

S5

2.44

7C

124

2.54

81

129

S6

2.95

97

151

3.05

9B

155

S7

3.45

B0

176

3.54

B4

180

S8

3.95

C9

201

4.02

CD

205

The linearity of the ADC converter of the ST6 is normally specified for

⎛2 LSB, therefore a minimum

distance of 4 LSB is needed between the edges of the resistance tolerance ranges. For the best re-

sults, a minimum of 8 LSB should be used (see Table 4).

Active Key

R Error Range

(LSB)

Distance to next

Key

Valid Key Range

S0

0

24

0-0

S1

2

22

18-1A

S2

3

22

30-33

S3

4

21

49-4E

S4

5

20

63-68

S5

5

22

7C-81

S6

5

21

97-9B

S7

4

22

B0-B4

S8

3

24

C9-CD

S9

2

25

E5-E6

Table 5. AD-Converter Results