ICL7106, ICL7107, ICL7107S

13

FN3082.9

October 24, 2014

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FIGURE 17. ICL7107 MEASURING RATIOMETRIC VALUES OF QUAD

LOAD CELL

FIGURE 18. ICL7106 USED AS A DIGITAL CENTIGRADE

THERMOMETER

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

GND

100pF

TO PIN 1

0.1µF

100kΩ

0.47µF

TO DISPLAY

The resistor values within the bridge are determined by the desired

sensitivity.

V+

0.22µF

47kΩ

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

0.01µF

100kΩ

100kΩ 1MΩ

9V

47kΩ

0.22µF

0.47µF

TO BACKPLANE

TO DISPLAY

A silicon diode-connected transistor has a temperature coefficient of

about -2mV/°C. Calibration is achieved by placing the sensing

transistor in ice water and adjusting the zeroing potentiometer for a

000.0 reading. The sensor should then be placed in boiling water and

the scale-factor potentiometer adjusted for a 100.0 reading.

SCALE

FACTOR

ADJUST

100kΩ 220kΩ

22kΩ

SILICON NPN

MPS 3704 OR

SIMILAR

ZERO

ADJUST