HD74LS47 Datasheet, PDF (2/7 Pages) Hitachi Semiconductor – BCD-to-Seven Segment Decoder Driver(with 15V outputs)

HD74LS47
Function Table
Decimal or
Inputs
BI/
Outputs
Function _{LT RBI D C B A} RBO _a
b
c
d
e
f
Note
g
0
H H LLLL
H
ON ON ON ON ON ON OFF
1
H X LLLH
H OFF ON ON OFF OFF OFF OFF
2
H X LLHL
H
ON ON OFF ON ON OFF ON
3
H X L LHH
H
ON ON ON ON OFF OFF ON
4
H X LHL L
H OFF ON ON OFF OFF ON ON
5
H X LHLH
H
ON OFF ON ON OFF ON ON
6
H X LHHL
H OFF OFF ON ON ON ON ON
7
H X LHHH
H
ON ON ON OFF OFF OFF OFF
1
8
H X HLLL
H
ON ON ON ON ON ON ON
9
H X HLLH
H
ON ON ON OFF OFF ON ON
10
H X HLHL
H OFF OFF OFF ON ON OFF ON
11
H X HLHH
H OFF OFF ON ON OFF OFF ON
12
H X HHL L
H OFF ON OFF OFF OFF ON ON
13
H X HHLH
H
ON OFF OFF ON OFF ON ON
14
H X HHHL
H OFF OFF OFF ON ON ON ON
15
H X HHHH
H OFF OFF OFF OFF OFF OFF OFF
BI
X X XXXX
L OFF OFF OFF OFF OFF OFF OFF 2
RBI
H L LLLL
L OFF OFF OFF OFF OFF OFF OFF 3
LT
L X XXXX
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 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 a 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.
a
f gb
e
c
d 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Rev.3.01, May 10, 2006, page 2 of 6