SN74LS247

http://onsemi.com

4

LS247

FUNCTION TABLE

DECIMAL

OR

INPUTS

BI/RBO

OUTPUTS

NOTE

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

ON

ON

ON

ON

ON

ON

OFF

1

H

X

L

LL

H

H

OFF

ON

ON

OFF

OFF

OFF

OFF

2

H

X

L

LHL

H

ON

ON

OFF

ON

ON

OFF

ON

3

H

X

L

LH

H

H

ON

ON

ON

ON

OFF

OFF

ON

4

H

X

L

H

L

L

H

OFF

ON

ON

OFF

OFF

ON

ON

5

H

X

L

HL

H

H

ON

OFF

ON

ON

OFF

ON

ON

6

H

X

L

HH

L

H

ON

OFF

ON

ON

ON

ON

ON

7

H

X

L

HH

H

H

ON

ON

ON

OFF

OFF

OFF

OFF

1

8

H

X

H

L

L

L

H

ON

ON

ON

ON

ON

ON

ON

9

H

X

H

LL

H

H

ON

ON

ON

ON

OFF

ON

ON

10

H

X

H

LHL

H

OFF

OFF

OFF

ON

ON

OFF

ON

11

H

X

H

LH

H

H

OFF

OFF

ON

ON

OFF

OFF

ON

12

H

X

H

H

L

L

H

OFF

ON

OFF

OFF

OFF

ON

ON

13

H

X

H

HL

H

H

ON

OFF

OFF

ON

OFF

ON

ON

14

H

X

H

HH

L

H

OFF

OFF

OFF

ON

ON

ON

ON

15

H

X

H

HH

H

H

OFF

OFF

OFF

OFF

OFF

OFF

OFF

BI

X

X

X

X

X

X

L

OFF

OFF

OFF

OFF

OFF

OFF

OFF

2

RBI

H

L

L

LL

L

L

OFF

OFF

OFF

OFF

OFF

OFF

OFF

3

LT

L

X

X

X

X

X

H

ON

ON

ON

ON

ON

ON

ON

4

H = HIGH Level, L = LOW Level, X = Irrelevant

NOTES: 1. The blanking input (BI) must be open or held at a high logic level when output functions 0 through 15 are desired. The ripple-blanking input (RBI) must

be open or high if blanking of a decimal zero is not desired.

2. When a low logic level is applied directly to the blanking input (BI), all segment outputs are off regardless of the level of any other input.

3. When ripple-blanking input (RBI) and inputs A, B, C, and D are at a low level with the lamp test input high, all segment outputs go off and the

ripple-blanking output (RBO) goes to a low level (response condition).

4. When the blanking input/ripple blanking output (BI/RBO) is open or held high and a low is applied to the lamp-test input, all segment outputs are on.

BI/RBO is wire-AND logic serving as blanking input (BI) and/or ripple-blanking output (RBO).