SN74LS249N 查看數據表（PDF） - Motorola => Freescale
零件编号
产品描述 (功能)
生产厂家
SN74LS249N Datasheet PDF : 8 Pages
| |||
SN54/74LS247 • SN54/74LS248 • SN54/74LS249
LS247
FUNCTION TABLE
DECIMAL
OR
INPUTS
BI/RBO
OUTPUTS
NOTE
FUNCTION LT RBI D C B A
a
b
c
d
e
f
g
0
HHL L L L
H
ON ON ON ON ON ON OFF
1
HXL L LH
H
OFF ON ON OFF OFF OFF OFF
2
HXL LHL
H
ON ON OFF ON ON OFF ON
3
HX L LHH
H
ON ON ON ON OFF OFF ON
4
HXLHL L
H
OFF ON ON OFF OFF ON ON
5
HX L H L H
H
ON OFF ON ON OFF ON ON
6
HX LHHL
H
ON OFF ON ON ON ON ON
7
HX LHHH
H
ON ON ON OFF OFF OFF OFF
1
8
HXHL L L
H
ON ON ON ON ON ON ON
9
HXHL LH
H
ON ON ON ON OFF ON ON
10
HXHLHL
H
OFF OFF OFF ON ON OFF ON
11
HXH L HH
H
OFF OFF ON ON OFF OFF ON
12
HXHHL L
H
OFF ON OFF OFF OFF ON ON
13
HXHH L H
H
ON OFF OFF ON OFF ON ON
14
HXHHH L
H
OFF OFF OFF ON ON ON ON
15
HXHHHH
H
OFF OFF OFF OFF OFF OFF OFF
BI
XXXXXX
RBI
HL L L L L
LT
LXXXXX
L
OFF OFF OFF OFF OFF OFF OFF
2
L
OFF OFF OFF OFF OFF OFF OFF
3
H
ON ON ON ON ON ON ON
4
LS248, LS249
FUNCTION TABLE
DECIMAL
OR
INPUTS
BI/RBO
OUTPUTS
FUNCTION LT RBI D C B A
a
b
c
d
e
f
g
NOTE
0
HHL L L L
H
H
H
H
H
H
H
L
1
1
HXL L LH
H
L
H
H
L
L
L
L
1
2
HXL LHL
H
H
H
L
H
H
L
H
3
HX L LHH
H
H
H
H
H
L
L
H
4
HXLHL L
H
L
H
H
L
L
H
H
5
HX L H L H
H
H
L
H
H
L
H
H
6
HX LHHL
H
H
L
H
H
H
H
H
7
HX LHHH
H
H
H
H
L
L
L
L
1
8
HXHL L L
H
H
H
H
H
H
H
H
9
HXHL LH
H
H
H
H
H
L
H
H
10
HXHLHL
H
L
L
L
H
H
L
H
11
HXH L HH
H
L
L
H
H
L
L
H
12
HXHHL L
H
L
H
L
L
L
H
H
13
HXHH L H
H
H
L
L
H
L
H
H
14
HXHHH L
H
L
L
L
H
H
H
H
15
HXHHHH
H
L
L
L
L
L
L
L
BI
XXXXXX
L
L
L
L
L
L
L
L
2
RBI
HL L L L L
L
L
L
L
L
L
L
L
3
LT
LXXXXX
H
H
H
H
H
H
H
H
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
NOTES: 1. 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
NOTES: 1. 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).
FAST AND LS TTL DATA
5-404
Share Link: 