BCD to 7-segment decoders

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

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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