A frequency divider is called an electronic device that divides the input frequency into an almost always whole or rational ratio. The shape of the output signal can be symmetrical or asymmetrical. The input signal is often in the form of a square wave but may also be sinusoidal or other forms.
They are usually made up of digital counters. Non-integer frequency ratios can be obtained using variable modulus counters, for example, if the counter module is changed between 2 and 3 at each output pulse, a frequency ratio of 5: 2 is obtained.
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