A circuit that responds to a specific set of signals to prod

A circuit that responds to a specific set of signals to produce a coded digital output is called a(n):

Question 7 options:

BCD matrix

display driver

encoder

decoder

Solution

D.Decoder

The Binary Decoder is another combinational logic circuit constructed from individual logic gates and is the exact opposite to that of an “Encoder” . The name “Decoder” means to translate or decode coded information from one format into another, so a digital decoder transforms a set of digital input signals into an equivalent decimal code at its output.

Binary Decoders are another type of digital logic device that has inputs of 2-bit, 3-bit or 4-bit codes depending upon the number of data input lines, so a decoder that has a set of two or more bits will be defined as having an n-bit code, and therefore it will be possible to represent 2n possible values. Thus, a decoder generally decodes a binary value into a non-binary one by setting exactly one of its n outputs to logic “1”.

If a binary decoder receives n inputs (usually grouped as a single Binary or Boolean number) it activates one and only one of its 2n outputs based on that input with all other outputs deactivated.

So for example, an inverter ( NOT-gate ) can be classed as a 1-to-2 binary decoder as 1-input and 2-outputs (21) is possible because with an input A it can produce two outputs A and A (not-A) as shown.

Then we can say that a standard combinational logic decoder is an n-to-m decoder, where m 2n, and whose output, Q is dependent only on its present input states. In other words, a binary decoder looks at its current inputs, determines which binary code or binary number is present at its inputs and selects the appropriate output that corresponds to that binary input.

A Binary Decoder converts coded inputs into coded outputs, where the input and output codes are different and decoders are available to “decode” either a Binary or BCD (8421 code) input pattern to typically a Decimal output code. Commonly available BCD-to-Decimal decoders include the TTL 7442 or the CMOS 4028. Generally a decoders output code normally has more bits than its input code and practical “binary decoder” circuits include, 2-to-4, 3-to-8 and 4-to-16 line configurations.