INPUTS

OUTPUTS

TRUTH TABLE

5-57

FAST AND LS TTL DATA

SN54/74LS47

14

15

LOGIC DIAGRAM

NUMERICAL DESIGNATIONS — RESULTANT DISPLAYS

0

1

2

3

4

5

6

7

8

9

10

11 12

13

INPUT

BLANKING INPUT OR

RIPPLE-BLANKING

OUTPUT

RIPPLE-BLANKING

INPUT

LAMP-TEST

INPUT

A

B

C

D

a

a

b

b

c

c

d

d

e

e

f

f

g

g

OUTPUT

DECIMAL

OR

FUNCTION

LT

RBI

D

C

B

A

BI/RBO

a

b

c

d

e

f

g

NOTE

0

H

H

L

L

L

L

H

L

L

L

L

L

L

H

A

1

H

X

L

L

L

H

H

H

L

L

H

H

H

H

A

2

H

X

L

L

H

L

H

L

L

H

L

L

H

L

3

H

X

L

L

H

H

H

L

L

L

L

H

H

L

4

H

X

L

H

L

L

H

H

L

L

H

H

L

L

5

H

X

L

H

L

H

H

L

H

L

L

H

L

L

6

H

X

L

H

H

L

H

H

H

L

L

L

L

L

7

H

X

L

H

H

H

H

L

L

L

H

H

H

H

8

H

X

H

L

L

L

H

L

L

L

L

L

L

L

9

H

X

H

L

L

H

H

L

L

L

H

H

L

L

10

H

X

H

L

H

L

H

H

H

H

L

L

H

L

11

H

X

H

L

H

H

H

H

H

L

L

H

H

L

12

H

X

H

H

L

L

H

H

L

H

H

H

L

L

13

H

X

H

H

L

H

H

L

H

H

L

H

L

L

14

H

X

H

H

H

L

H

H

H

H

L

L

L

L

15

H

X

H

H

H

H

H

H

H

H

H

H

H

H

BI

X

X

X

X

X

X

L

H

H

H

H

H

H

H

B

RBI

H

L

L

L

L

L

L

H

H

H

H

H

H

H

C

LT

L

X

X

X

X

X

H

L

L

L

L

L

L

L

D

H = HIGH Voltage Level

L = LOW Voltage Level

X = Immaterial

NOTES:

(A) BI/RBO is wire-AND logic serving as blanking Input (BI) and/or ripple-blanking output (RBO). The blanking out (BI) must be open or held

at a HIGH level when output functions 0 through 15 are desired, and ripple-blanking input (RBI) must be open or at a HIGH level if blanking

of a decimal 0 is not desired. X = input may be HIGH or LOW.

(B) When a LOW level is applied to the blanking input (forced condition) all segment outputs go to a LOW level regardless of the state of

any other input condition.

(C) When ripple-blanking input (RBI) and inputs A, B, C, and D are at LOW level, with the lamp test input at HIGH level, all segment outputs

go to a HIGH level and the ripple-blanking output (RBO) goes to a LOW level (response condition).

(D) When the blanking input/ripple-blanking output (BI/RBO) is open or held at a HIGH level, and a LOW level is applied to lamp test input,

all segment outputs go to a LOW level.