SN74LS248 Motorola, SN74LS248 Datasheet - Page 3

• Manufacturer Part Number: SN74LS248
• Description: BCD-TO-SEVEN-SEGMENT DECODERS/DRIVERS
• Manufacturer: Motorola

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
NOTES: 1.
NOTES: 1.
BI/RBO is wire-AND logic serving as blanking input (BI) and/or ripple-blanking output (RBO).
FUNCTION
FUNCTION
FUNCTION
FUNCTION
DECIMAL
DECIMAL
RBI
RBI
OR
OR
OR
OR
10
11
12
13
14
15
LT
10
11
12
13
14
15
LT
BI
BI
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
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
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.
be open or high if blanking of a decimal zero is not desired.
ripple-blanking output (RBO) goes to a low level (response condition).
LT
LT
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
X
H
X
L
L
RBI
RBI
H
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
H
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
L
L
SN54/74LS247 SN54/74LS248 SN54/74LS249
D
H
H
H
H
H
H
H
H
D
H
H
H
H
H
H
H
H
X
X
L
L
L
L
L
L
L
L
X
L
X
INPUTS
L
L
L
L
L
L
L
L
L
INPUTS
C
H
H
H
H
H
H
H
H
X
X
C
H
H
H
H
H
H
H
H
X
X
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
B
H
H
H
H
H
H
H
H
B
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
X
L
X
L
L
L
L
L
L
L
L
X
L
X
A
H
H
H
H
H
H
H
H
X
X
A
H
H
H
H
H
H
H
H
X
X
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
FAST AND LS TTL DATA
FUNCTION TABLE
FUNCTION TABLE
BI/RBO
BI/RBO
BI/RBO
BI/RBO
LS248, LS249
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
L
L
L
LS247
5-404
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
H
H
H
H
H
H
H
H
H
H
a
L
L
L
L
L
L
L
L
L
a
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
b
H
H
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
L
b
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
H
H
H
H
H
H
H
H
H
H
H
c
L
L
L
L
L
L
L
L
c
OUTPUTS
OUTPUTS
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
d
H
H
H
H
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
d
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
H
H
H
H
H
H
H
e
L
L
L
L
L
L
L
L
L
L
L
L
e
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
H
H
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
L
f
f
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
H
H
H
H
H
H
H
H
H
H
H
H
H
g
L
L
L
L
L
L
g
NOTE
NOTE
NOTE
NOTE
1
1
1
2
3
4
1
2
3
4