3-250

TELCOM SEMICONDUCTOR, INC.

TC7136

TC7136A

LOW POWER, 3-1/2 DIGIT

ANALOG-TO-DIGITAL CONVERTERS

COMMON

TC7136/A PIN DESCRIPTION

Pin No.

40-Pin PDIP

Normal

(Reverse)

Name

Description

1

(40)

Positive supply voltage.

2

(39)

Activates the D section of the units display.

3

(38)

Activates the C section of the units display.

4

(37)

Activates the B section of the units display.

5

(36)

Activates the A section of the units display.

6

(35)

Activates the F section of the units display.

7

(34)

Activates the G section of the units display.

8

(33)

Activates the E section of the units display.

9

(32)

Activates the D section of the tens display.

10

(31)

Activates the C section of the tens display.

11

(30)

Activates the B section of the tens display.

12

(29)

Activates the A section of the tens display

13

(28)

Activates the F section of the tens display.

14

(27)

Activates the E section of the tens display.

15

(26)

Activates the D section of the hundreds display.

16

(25)

Activates the B section of the hundreds display.

17

(24)

Activates the F section of the hundreds display.

18

(23)

Activates the E section of the hundreds display.

19

(22)

Activates both halves of the 1 in the thousands display.

20

(21)

POL

Activates the negative polarity display.

21

(20)

BP

Backplane drive output.

22

(19)

Activates the G section of the hundreds display.

23

(18)

Activates the A section of the hundreds display.

24

(17)

Activates the C section of the hundreds display.

25

(16)

Activates the G section of the tens display.

26

(15)

Negative power supply voltage.

27

(14)

The integrating capacitor should be selected to give the maximum voltage

swing that ensures component tolerance build-up will not allow the integrator

output to saturate. When analog common is used as a reference and the

conversion rate is 3 readings per second, a 0.047

µF capacitor may be used.

The capacitor must have a low dielectric constant to prevent roll-over errors.

See Integrating Capacitor section for additional details.

28

(13)

Integration resistor connection. Use a 180 k

Ω for a 200 mV full-scale range

and a 1.8 M

Ω for 2V full-scale range.

29

(12)

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

µF

capacitor for a 200 mV full scale, and a 0.1

µF capacitor for a 2V full scale. See

paragraph on Auto-Zero Capacitor for more details.

30

(11)

–

The low input signal is connected to this pin.

31

(10)

+

The high input signal is connected to this pin.

32

(9)

ANALOG

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. See paragraph on Analog Common for more details. It also acts as a

reference voltage source.