Pin Number

Pin Name

Description

1

Supply voltage (+)

Provides the operating voltage for the IC

2,3,4,5,6,7 and 8

7-Segment 4th digit

These pins are connected to the 7-segment display for displaying the once digit of output value.

9,10,11,12,13,14 and 25

7-segment 3rd digit

These pins are connected to 7-segment  for displaying the tenth digit

15,16,17,18,22,23 and 24

7-sement 2nd digit

These pins are connected to 7-segment  for displaying the hundredth digit

19 and 20

7-segment 1st digit

These pins are connected to 7-segment  for displaying the thousandth digit

21

Ground

Connected to the round of the system

26

Supply voltage (-)

Provide the negative supply voltage

27

Signal integrate

Connected to a capacitor

28 and 29

Auto Zero and buff

Connected to capacitor and resistor network

30 and 31

Input High and Input Low

The analog voltage that has to be measured is connected here

32

Common

Connected to ground

33 and 34

Cref+ and Cref-

Capacitor is connected across these pins for neutralizing fluctuations in reference voltage

35 and 36

Reference High and Reference Low

Either can supply reference voltage or use internal reference voltage

37

Test pin

Not used during operation

38, 39 and 40

OSC1, OSC2, OSC3

Use RC network top set oscillator frequency