This tool calculates the duty cycle from frequency (units: Hz/kHz/MHz/GHz)
Calculator
Enter
- Frequency of the waveform
- Pulse width
Use the drop down menu to select units for each.
What is duty cycle?
The duty cycle is a measure of the “on” time of a periodic waveform – also known as Pulse Width (PW), compared to the total period (T) of the waveform expressed as a percentage. This is shown in the picture below.
To calculate duty cycle from frequency (f), we first calculate the Period (T)
where
T = 1/f
Duty cycle = (PW/T)*100
where PW < T
Duty cycle is used to describe the behavior of pulse waveforms or signals. A high duty cycle (%) indicates that the signal is on for most of the time, while a low duty cycle means the signal is on for only a small portion of the time.
Formula and Example Calculation
Mathematically, the duty cycle is calculated by dividing the duration of the pulse “on” time (also known as the active state or pulse width) by the total duration of the pulse. The result is then multiplied by 100 to express it as a percentage.
For instance, if a pulse is on for 2 nanoseconds (ns) and the frequency of the pulse is 1 MHz.
The period of the pulse is 1/(1 MHz) = 0.000001s
Duty Cycle = (2*10-9/1*10-6) * 100
In this case, the duty cycle is 0.2 %
How is duty cycle measured?
Duty cycle can be measured using an oscilloscope, a widely used electronic instrument that visually displays the waveform of an electrical signal. By analyzing the waveform on the oscilloscope screen, one can determine the duration of the pulse “on” time and the total period of the waveform. Subsequently, the duty cycle can be calculated using the aforementioned formula.
Before making your measurement, check the oscilloscope bandwidth specifications – both the pulse duration and the rise time matter
Related Calculators
- Duty cycle from period
- PWM to Voltage