Ripple Counter (Asynchronous Counter)

A simple counter, the MOD-16 Ripple counter can be created by combining four JK flip-flops. MOD-16 means the counter has 16 binary states. Each flip-flop is fixed and operates in toggle mode (J and K are both held high).

The first flip-flop takes the clock signal and divides it by 2 at output Q0, then the second flip-flop does the same. This process continues and eventually a 4-bit binary counter is obtained. The least significant bit (LSB) is Q0, and the most significant bit (MSB) is Q3. When the count reaches 1111, the counter returns to 0000 and continues counting.

When the counter is attempted to reset, the active low clear line is triggered with a low pulse and the counter counts down from 1111, using only the Q outputs.

This surge counter can also be used as a division counter by 2, 4, 8, 16. It can be divided into different frequencies by changing the clock signal. For example, you only need the first flip-flop to get a divide by 2 counter; To get the divide by 8 counter, you need the first three flip-flops.

Ripple counters with higher MOD values can be created using more flip-flops. For example, if you want to create a MOD-10 (0 to 9) surge counter, you can configure the flip-flops accordingly. If you want to stop the counter when it reaches a certain value, you can use an output such as LED or buzzer.

Therefore, such a Ripple counter has a flexible structure that can have different MOD values and can be used in various applications.