3-76

TELCOM SEMICONDUCTOR, INC.

PERSONAL COMPUTER

DATA ACQUISITION A/D CONVERTER

TC835

TYPICAL APPLICATIONS DIAGRAMS

4-1/2 Digit ADC with Multiplexed Common Cathode LED Display

TC04

28

27

26

25

24

23

22

21

9

8

7

6

5

4

3

2

1

REF IN

ANALOG

GND

INT

OUT

AZ IN

BUFF

OUT

CREF

+5V

–5V

6.8V

UR

DGND

POLARITY

OR

STROBE

RUN/HOLD

CLK IN

BUSY

1

2

3

4

5

6

7

8

9

SET VREF = 1V

1.22V

100

k

Ω

ANALOG

GND

0.33 µF

100 k

Ω

1 µF

47

k

Ω

150

Ω

+5V

150

Ω

10

11

12

13

14

15

16

17

18

+5V

CD4513

BE

1 µF

20

19

18

17

16

15

–INPUT

+INPUT

V

+

D5 (MSD)

B1 (LSB)

B2

(LSD) D1

D2

D3

D4

B4

(MSB) B8

10

11

12

13

14

100

k

Ω

SIG

IN

+

–

0.1

µF

+5V

fOSC = 200 kHz

+

CREF

–

V –

TC835

TC04

TC7211A

INT OUT

AZ IN

BUFF OUT

+INPUT

–INPUT

ANALOG

COMMON

REF

IN

V–

POL

V+

20

19

18

17

16

15

14

13

12

26

27

D1

D2

D3

D4

B8

B4

B2

B1

D5

STROBE

OR

5

31

32

33

34

30

29

28

27

V+

D1

D2

D3

D4

B1

BP

B3

B2

B0

GND

Q

R

S

D

CLK

CD4071

+5V

1/4 CD4030

4-1/2 DIGIT LCD

SEGMENT

DRIVE

1

35

+5V

+5V

–5V

+

–

4

5

6

10

9

3

2

1/4 CD4081

1/2 CD4030

23

CD4081

1/4 CD4030

1/2

CD4013

6.8 k

Ω

100 k

Ω

100 k

Ω

100 k

Ω

0.33 µF

1 µF

ANALOG

INPUT

1

200 kHz

22

fIN

TC835

TC7660

11

1

+5V

8

23

(–5V)

V

+

V

–

24

10 µF

5

4

10 µF

+

+

TC835

Negative Supply Voltage Generator