TC7116/A/TC7117/A

DS21457B-page 6

© 2002 Microchip Technology Inc.

2.0

PIN DESCRIPTIONS

The descriptions of the pins are listed in Table 2-1.

TABLE 2-1:

PIN FUNCTION TABLE

Pin Number

(40-Pin PDIP)

(40-Pin CERDIP)

Pin Number

(44-Pin PQFP)

Symbol

Description

1

8

HLDR

Hold pin, Logic 1 holds present display reading.

29

Activates the D section of the units display.

310

Activates the C section of the units display.

411

Activates the B section of the units display.

512

Activates the A section of the units display.

613

Activates the F section of the units display.

714

Activates the G section of the units display.

815

Activates the E section of the units display.

916

Activates the D section of the tens display.

10

17

Activates the C section of the tens display.

11

18

Activates the B section of the tens display.

12

19

Activates the A section of the tens display.

13

20

Activates the F section of the tens display.

14

21

Activates the E section of the tens display.

15

22

Activates the D section of the hundreds display.

16

23

Activates the B section of the hundreds display.

17

24

Activates the F section of the hundreds display.

18

25

Activates the E section of the hundreds display.

19

26

Activates both halves of the 1 in the thousands display.

20

27

POL

Activates the negative polarity display.

21

28

BP/

GND

LCD backplane drive output (TC7116/TC7116A). Digital ground

(TC7117/TC7117A).

22

29

Activates the G section of the hundreds display.

23

30

Activates the A section of the hundreds display.

24

31

Activates the C section of the hundreds display.

25

32

Activates the G section of the tens display.

26

34

V-

Negative power supply voltage.

27

35

Integrator output. Connection point for integration capacitor.

See Section 4.3, Integrating Capacitor for more details.

28

36

Integration resistor connection. Use a 47k

Ω resistor for a 200mV full scale range

and a 470k

Ω resistor for 2V full scale range.

29

37

The size of the auto-zero capacitor influences system noise. Use a 0.47

µF

capacitor for 200mV full scale, and a 0.047

µF capacitor for 2V full scale.

See Section 4.1, Auto-Zero Capacitor for more details.

30

38

The analog LOW input is connected to this pin.

31

39

The analog HIGH input signal is connected to this pin.

32

40

COMMON This pin is primarily used to set the Analog Common mode voltage for battery

operation, or in systems where the input signal is referenced to the power supply.

It also acts as a reference voltage source. See Section 3.1.6, Analog Common

for more details.

33

41

34

42

used, a 1

µF capacitor is recommended and will hold the rollover error to

0.5 count.