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Renesas Electronics Europe - Knowledgebase

Duty cycle

Latest Updated:02/01/2006


Duty cycle


The ratio of the active level width of a fixed-cycle signal such as a clock to the cycle (tACT/tCY) is known as the duty. The duty is expressed as a percentage, so a duty of 50%, for example, means that the active level width and inactive level width are the same.

When a circuit is driven by a clock, etc., if the duty is close to 0% or 100%, the circuit can generally not operate normally, so the minimum high-level and low-level width is prescribed.
A clock signal with a duty of 50% can be obtained by dividing in half a clock that is double the required frequency using a flip-flop circuit.

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