What is a 2-to-4 line decoder?

What is a 2-to-4 line decoder?

The 2-to-4 line binary decoder depicted above consists of an array of four AND gates. The 2 binary inputs labelled A and B are decoded into one of 4 outputs, hence the description of 2-to-4 binary decoder. Each output represents one of the minterms of the 2 input variables, (each output = a minterm).

How many enable lines are available in 2-to-4 line decoder?

The SN74HC139 device comprises two individual 2-line to 4-line decoders in a single package. The active-low enable (G) input can be used as a data line in demultiplexing applications. This decoder/demultiplexer features fully buffered inputs, each of which represents only one normalized load to its driving circuit.

What is the IC number of the 2×4 decoder?

IC 74LS155
IC 74LS155 DUAL 2-to-4 LINE DECODER/DEMULTIPLEXER.

What are the ICs required to design a 2/4 line decoder?

Typical decoder ICs might include two 2-4 line circuits, a 3-8 line circuit, or a 4-16 line decoder circuit. One exclusion to the binary character of this circuit is the 4-10 line decoders, which is proposed to alter a Binary Coded Decimal (BCD) input to a 0-9 range output.

How many 2/4 decoders will be used to design a 4/16 decoder with an enable input?

Therefore, we require two 3 to 8 decoders for implementing one 4 to 16 decoder.

Which logic gates are required to design and implement 2-to-4 active high decoder?

2-to-4 Line NAND Binary Decoder Generally to implement this enabling function the 2-input AND or NAND gates are replaced with 3-input AND or NAND gates. The additional input pin represents the enable function.

What is the active logic level of a 2×4 decoder?

1
A 2-to-4 Binary Decoders The binary inputs A and B determine which output line from Q0 to Q3 is “HIGH” at logic level “1” while the remaining outputs are held “LOW” at logic “0” so only one output can be active (HIGH) at any one time.

What is a decoder in logic circuits?

A decoder is a circuit that changes a code into a set of signals. It is called a decoder because it does the reverse of encoding, but we will begin our study of encoders and decoders with decoders because they are simpler to design.

How many inputs are needed for a 16 decoder?

Explanation: A binary decoder is a combinational logic circuit which decodes binary information from n-inputs to a maximum of 2n outputs. Here, number of outputs = 16. 16 = 24 = 2n. Thus, number of inputs is 4.

How many 2×4 decoders are needed for 4×16?

So take two such 2-by-4 decoders which give you four input lines. Let the output lines be a0,a1,a2,a3 for one decoder and b0,b1,b2,b3 for the other.

What is the circuit diagram of 2 to 4 decoder?

The circuit diagram of 2 to 4 decoder is shown in the following figure. Therefore, the outputs of 2 to 4 decoder are nothing but the min terms of two input variables A 1 & A 0, when enable, E is equal to one. If enable, E is zero, then all the outputs of decoder will be equal to zero.

How many output lines can a decoder have?

So, if n represents given input lines then possible output lines would be 2 n . Decoder with two inputs would give 4 outputs (n=2,2 2 that is 4).

How to construct a decoder with a block diagram?

A block diagram of decoder consists input lines, one or more enable inputs and maximum number of output lines. To construct a decoder, we require to know the number of all possible output lines that totally depends on the given input. So, if n represents given input lines then possible output lines would be 2 n.

How to make a 3 by 8 decoder work?

Well it takes 3 inputs and multiplies them, basically with an 3 by 8 decoder you will get 2^3 outputs. So you are trying to achieve this with a smaller 2 by 4 decoder which looks like this. Here you have 2 inputs, 4 outputs, 4 ANDs, 2 NOTs, each AND has 2 inputs. Now you have to think how can you turn 4 inputs into 3 to make this thing work.