Non-binary Counter in Digital Electronics

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In digital electronics, a counter is a type of sequential circuit which is made up of flip-flops and is used to count number of clock pulses or events occur over time. There are two major types of counters namely, binary counter and non-binary counter.

This chapter is meant for explaining concept of non-binary counter, its types, design procedure, applications, etc. So lets begin with the basic definition of non-binary counter.

What is a Non-Binary Counter?

The type of digital counter that uses a number system (such as base 3, base 7, base 10, etc.) except the binary number system (base 2) is referred to as a non-binary counter.

Therefore, a non-binary counter is one that does not use binary number system to represent counts. In the non-binary counter, the count values are represented in terms of digits of the particular number system that the counter uses.

For example, in a decimal (base 10) counter, each stage has ten possible states that are represented by the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.

We can design a non-binary counter using many types of digital electronic components like flip-flops, combinational circuits, counters with preset and clear inputs, etc. The selection of design components depend upon the desired performance of the counter.

Types of Non-Binary Counters

There are many types of non-binary counters available that are used in digital systems. The most commonly used types of non-binary counters are explained below.

• Ternary Counter − The type of non-binary counter that uses a base 3 number system is known as a ternary counter. Therefore, the ternary counter can have three possible states specified by the digits 0, 1, and 2. The count sequence that the ternary counter have can be 0, 1, 2, 10, 11, 12, 20, 21, 22
• Quaternary Counter − The type of non-binary counter that uses a base 4 number system to represent the count states is known as a quaternary counter. Thus, the quaternary counter can have four possible states that are specified by the digits 0, 1, 2, and 3. Hence, the count sequence of the quaternary count will be 0, 1, 2, 3, 10, 11, 12, 13, 20, 21, 22, 23, 30
• Gray Code Counter − The type of non-binary counter that uses Gray codes to represent the count states is known as gray code counter. In the gray code counter, the count sequence is 0, 1, 3, 2, 6, 7, 5, 4, 12, 13
• Decimal Counter − The type of non-binary counter that uses base 10 number system to represent the count states is known as a decimal counter. Therefore, the decimal counter can have ten possible states which are represented by the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11

Design of Non-Binary Counter

The designing of a typical non-binary counter is done as per the following steps −

Step 1 − Firstly, determine the type of number system or base of the non-binary number system that need to be used.

Step 2 − Identify the number of count stages that the counter would have, where each count stage of the counter will be represented by one digit of the non-binary number system.

Step 3 − Identify the possible states of each count stage according to the non-binary number system. For example, in a decimal number system, each stage can have ten possible states represented by the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.

Step 4 − Select a type of flip flop to represent each stage of the counter. The selected flip-flop must have enough states to represent all the possible states of the stage.

Step 5 − Connect all the flip flops together to form the counter circuit and test the counter to ensure that it is working properly.

Advantages of Non-Binary Counters

The following are the chief advantages of the non-binary counters −

• Non-binary counter can count to higher number of stages than a binary counter. For example, a decimal counter can count up to 10 stages.
• Non-binary counter are immune to noise and electrical interference.
• Non-binary counters have better accuracy and resolution over a wider range of frequencies.
• In some applications, non-binary counters have reduced circuit complexity and size than binary counters.

Limitations of Non-Binary Counters

Though, non-binary counters have several advantages, but they also have some limitations that should be taken into account while using them in digital circuit design −

• The circuitry of non-binary counters is more complex as compared binary counters.
• Non-binary counters use non-standard interface. Therefore, they cannot be easily interfaced with other digital circuits.
• Non-binary counters consumes more power due to complex circuitry.
• Non-binary counters are not available in a wider range.
• Non-binary counters are relatively more expensive than binary counters.

Applications of Non-Binary Counters

The non-binary counters are used in numerous applications in digital electronics. Some common uses of non-binary counters are listed as follows −

• Non-binary counters are used in computers to perform arithmetic operations such as multiplication and division.
• Non-binary counters are used in digital signal processing to realize algorithms.
• Non-binary counters are also used in pulse position modulation (PPM) to encode and transmit signals over communication channels.
• Non-binary counters are also used in time division multiplexing (TDM) applications.
• Non-binary counters are used in analog to digital converters (ADCs).
• Non-binary counters are also used in control systems to implement control algorithms.

Conclusion

In conclusion, a non-binary counter is a type of digital counter that does not use binary number system, instead, it uses a different number system to count. Non-binary counters are used in digital applications where higher resolution and accuracy is desired.