74LS47N Decoder
74LS47N is a BCD to 7-Segment
active-low decoder with open-collector outputs to drive indicator
segments directly. The decoder accepts
4-bit binary-coded-decimal (BCD) and, depending on the state of the auxiliary inputs, decodes this data to drive a 7-segment display indicator. 
Function Table
Decimal/
Function |
Inputs |
Outputs |
~LT |
~RBI |
D |
C |
B |
A |
~BI/RBO |
OA
|
OB
|
OC
|
OD
|
OE
|
OF
|
OG
|
0 |
H |
H |
L |
L |
L |
L |
H |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
H(OFF) |
1 |
H |
X |
L |
L |
L |
H |
H |
H(OFF) |
L(ON) |
L(ON) |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
2 |
H |
X |
L |
L |
H |
L |
H |
L(ON) |
L(ON) |
H(OFF) |
L(ON) |
L(ON) |
H(OFF) |
L(ON) |
3 |
H |
X |
L |
L |
H |
H |
H |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
H(OFF) |
H(OFF) |
L(ON) |
4 |
H |
X |
L |
H |
L |
L |
H |
H(OFF) |
L(ON) |
L(ON) |
H(OFF) |
H(OFF) |
L(ON) |
L(ON) |
5 |
H |
X |
L |
H |
L |
H |
H |
L(ON) |
H(OFF) |
L(ON) |
L(ON) |
H(OFF) |
L(ON) |
L(ON) |
6 |
H |
X |
L |
H |
H |
L |
H |
H(OFF) |
H(OFF) |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
7 |
H |
X |
L |
H |
H |
H |
H |
L(ON) |
L(ON) |
L(ON) |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
8 |
H |
X |
H |
L |
L |
L |
H |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
9 |
H |
X |
H |
L |
L |
H |
H |
L(ON) |
L(ON) |
L(ON) |
H(OFF) |
H(OFF) |
L(ON) |
L(ON) |
10 |
H |
X |
H |
L |
H |
L |
H |
H(OFF) |
H(OFF) |
H(OFF) |
L(ON) |
L(ON) |
H(OFF) |
L(ON) |
11 |
H |
X |
H |
L |
H |
H |
H |
H(OFF) |
H(OFF) |
L(ON) |
L(ON) |
H(OFF) |
H(OFF) |
L(ON) |
12 |
H |
X |
H |
H |
L |
L |
H |
H(OFF) |
L(ON) |
H(OFF) |
H(OFF) |
H(OFF) |
L(ON) |
L(ON) |
13 |
H |
X |
H |
H |
L |
H |
H |
L(ON) |
H(OFF) |
H(OFF) |
L(ON) |
H(OFF) |
L(ON) |
L(ON) |
14 |
H |
X |
H |
H |
H |
L |
H |
H(OFF) |
H(OFF) |
H(OFF) |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
15 |
H |
X |
H |
H |
H |
H |
H |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
BI |
X |
X |
X |
X |
X |
X |
L |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
RBI |
H |
L |
L |
L |
L |
L |
L |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
H(OFF) |
LT |
L |
X |
X |
X |
X |
X |
H |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
L(ON) |
L(ON)
|
H = HIGH Level
L = LOW Level
X = Don't Care
BI/RBO = Blanking input/ripple blanking output
RBI = Ripple-blanking input
LT = Lamp test
ON/OFF - state of the SSD LEDs
74LS48N Decoder
74LS48N is a BCD to 7-Segment active-high decoder with internal 2K Ohms pull-ups. The decoder accepts 4-bit binary-coded-decimal (BCD) and, depending on the state of the auxiliary inputs, decodes this data to drive a 7-segment display indicator.

Function Table
Decimal/
Function |
Inputs |
Outputs |
~LT |
~RBI |
D |
C |
B |
A |
~BI/RBO |
OA
|
OB
|
OC
|
OD
|
OE
|
OF
|
OG
|
0 |
H |
H |
L |
L |
L |
L |
H |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
L(OFF) |
1 |
H |
X |
L |
L |
L |
H |
H |
L(OFF) |
H(ON) |
H(ON) |
L(OFF) |
L(OFF) |
L(OFF) |
L(OFF) |
2 |
H |
X |
L |
L |
H |
L |
H |
H(ON) |
H(ON) |
L(OFF) |
H(ON) |
H(ON) |
L(OFF) |
H(ON) |
3 |
H |
X |
L |
L |
H |
H |
H |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
L(OFF) |
L(OFF) |
H(ON) |
4 |
H |
X |
L |
H |
L |
L |
H |
L(OFF) |
H(ON) |
H(ON) |
L(OFF) |
L(OFF) |
H(ON) |
H(ON) |
5 |
H |
X |
L |
H |
L |
H |
H |
H(ON) |
L(OFF) |
H(ON) |
H(ON) |
L(OFF) |
H(ON) |
H(ON) |
6 |
H |
X |
L |
H |
H |
L |
H |
L(OFF) |
L(OFF) |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
7 |
H |
X |
L |
H |
H |
H |
H |
H(ON) |
H(ON) |
H(ON) |
L(OFF) |
L(OFF) |
L(OFF) |
L(OFF) |
8 |
H |
X |
H |
L |
L |
L |
H |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
9 |
H |
X |
H |
L |
L |
H |
H |
H(ON) |
H(ON) |
H(ON) |
L(OFF) |
L(OFF) |
H(ON) |
H(ON) |
10 |
H |
H |
L |
L |
L |
L |
H |
L(OFF)
|
L(OFF)
|
L(OFF)
|
H(ON) |
H(ON) |
L(OFF)
|
H(ON)
|
11 |
H |
H |
L |
L |
L |
L |
H |
L(OFF)
|
L(OFF)
|
H(ON) |
H(ON) |
L(OFF)
|
L(OFF)
|
H(ON)
|
12 |
H |
H |
L |
L |
L |
L |
H |
L(OFF)
|
H(ON) |
L(OFF)
|
L(OFF)
|
L(OFF)
|
H(ON) |
H(ON)
|
13 |
H |
H |
L |
L |
L |
L |
H |
H(ON) |
L(OFF)
|
L(OFF)
|
H(ON) |
L(OFF)
|
H(ON) |
H(ON)
|
14 |
H |
H |
L |
L |
L |
L |
H |
L(OFF)
|
L(OFF)
|
L(OFF)
|
H(ON) |
H(ON) |
H(ON) |
H(ON)
|
15 |
H |
H |
L |
L |
L |
L |
H |
L(OFF)
|
L(OFF)
|
L(OFF)
|
L(OFF)
|
L(OFF)
|
L(OFF)
|
L(OFF) |
BI |
X
|
X
|
X
|
X
|
X
|
X
|
L
|
L(OFF)
|
L(OFF)
|
L(OFF)
|
L(OFF)
|
L(OFF)
|
L(OFF)
|
L(OFF) |
RBI |
H
|
L
|
L |
L |
L |
L |
L
|
L(OFF)
|
L(OFF) | L(OFF) |
L(OFF)
|
L(OFF)
|
L(OFF)
|
L(OFF) |
LT |
L
|
X
|
X
|
X
|
X
|
X
|
H |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
H(ON) |
H(ON)
|
H = HIGH Level
L = LOW Level
X = Don't Care
BI/RBO = Blanking input/ripple blanking output
RBI = Ripple-blanking input
LT = Lamp test
ON/OFF - state of the SSD LEDs