ICL7106, ICL7107, ICL7107S

FN3082 Rev 9.00

Page 14 of 17

October 24, 2014

FIGURE 19. CIRCUIT FOR DEVELOPING UNDERRANGE AND

OVERRANGE SIGNAL FROM ICL7106 OUTPUTS

FIGURE 20. CIRCUIT FOR DEVELOPING UNDERRANGE AND

OVERRANGE SIGNALS FROM ICL7107 OUTPUT

FIGURE 21. AC TO DC CONVERTER WITH ICL7106

13

1

2

3

4

5

6

7

8

9

10

11

12

14

15

16

17

18

19

20

V+

D1

C1

B1

A1

F1

G1

E1

D2

C2

B2

A2

F2

E2

D3

B3

F3

E3

AB4

POL

28

40

39

38

37

36

35

34

33

32

31

30

29

27

26

25

24

23

22

21

OSC 1

OSC 2

OSC 3

TEST

REF HI

REF LO

COMMON

IN HI

IN LO

A-Z

BUFF

INT

V-

G2

C3

A3

G3

BP

O/RANGE

U/RANGE

CD4023 OR

74C10

CD4077

TO LOGIC

V+

TO

LOGIC

V-

GND

O/RANGE

U/RANGE

CD4023 OR

74C10

TO LOGIC

+5V

V-

33kΩ

The LM339 is required to

ensure logic compatibility

with heavy display loading.

13

1

2

3

4

5

6

7

8

9

10

11

12

14

15

16

17

18

19

20

V+

D1

C1

B1

A1

F1

G1

E1

D2

C2

B2

A2

F2

E2

D3

B3

F3

E3

AB4

POL

28

40

39

38

37

36

35

34

33

32

31

30

29

27

26

25

24

23

22

21

OSC 1

OSC 2

OSC 3

TEST

REF HI

REF LO

COMMON

IN HI

IN LO

A-Z

BUFF

INT

V-

G2

C3

A3

G3

BP

12kΩ

+

-

LM339

28

40

39

38

37

36

35

34

33

32

31

30

29

27

26

25

24

23

22

21

OSC 1

OSC 2

OSC 3

TEST

REF HI

REF LO

COMMON

IN HI

IN LO

A-Z

BUFF

INT

V -

G2

C3

A3

G3

BP

100pF

TO PIN 1

0.1µF

100kΩ

1kΩ

22kΩ

47kΩ

0.22µF

0.47µF

TO BACKPLANE

TO DISPLAY

Test is used as a common-mode reference level to ensure compatibility with most op amps.

10µF

9V

10µF

470kΩ

1µF

4.3kΩ

100pF

(FOR OPTIMUM BANDWIDTH)

1µF

10kΩ

10kΩ

1N914

1µF

0.22µF

5µF

CA3140

2.2MΩ

+

-

100kΩ

AC IN

SCALE FACTOR ADJUST

+

-