CA3162

FN1080 Rev.3.00

Page 6 of 8

Apr 2002

CA3162E Common-Cathode, LED Display Application

Figure 4 shows the CA3162E connected to a CD4511B

decode/driver to operate a common-cathode LED display.

Unlike the CA3161E, the CD4511B remains blank for all BCD

codes greater than nine. After 999mV the display blanks rather

than displaying EEE, as with the CA3161E. When displaying

negative voltage, the first digit remains blank, instead of (-),

and during a negative or positive overrange the display blanks.

The additional logic shown within the dotted area of Figure 4

restores the negative sign (-), allowing the display of negative

numbers as low as -99mV. Negative overrange is indicated by

a negative sign (-) in the MSD position. The rest of the display

is blanked. During a positive overrange, only segment b of the

MSD is displayed. One inverter from the CD4049B is used to

operate the decimal points. By connecting the inverter input to

either the MSD or NSD line either DP1 or DP2 will be dis-

played.

FIGURE 4. TYPICAL COMMON-CATHODE LED APPLICATION

14

15

16

9

13

12

11

10

1

2

3

4

5

7

6

8

CD4049UB

CD4049UB

V+

1.8k



1.8k



1.8k



1.8k



1.8k



1.2k



1.2k



12

11 10

9

8

7

6

5

4

3

2

1

DP1

DP2

fa

g

g

f

V+

e

a

b

c

d

B

C

LT

BL

LE/STROBE

A

D

GND

14

15

16

9

13

12

11

10

1

2

3

4

5

7

6

8

V+

C

D

ZERO

GAIN

INT

HIGH

LOW

B

A

NSD

MSD

LSD

GND

HOLD

ZERO

V+

0.27

F

10k



GAIN

INPUT

V+

100k



100k



100k



100k



50k



V+

100

k



100

k



100

k



V+

CD4012B

22k



V+

100k



DP1

DP2

6 BUFFERS

(1 CD4050B)

CD4511B

CA3162E

HP5082-7433

OR EQUIVALENT