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What is the duty cycle of a square pulse?
A duty cycle is the percentage of the waveform that occurs above the zero axis. The duty cycle of a square wave is always 50%, or 1/2. Because the duty cycle is 1/2, every second harmonic is not present.
What is a 25% duty cycle?
For example, a signal (10101010) has 50% duty cycle, because the pulse remains high for 1/2 of the period or low for 1/2 of the period. Similarly, for pulse (10001000) the duty cycle will be 25% because the pulse remains high only for 1/4 of the period and remains low for 3/4 of the period.
Can a 555 oscillator change the duty cycle?
Here is a simple oscillator circuit that varies the duty cycle over a wide range without affecting the frequency. It is a variation of the simple 555 astable oscillator. Initially, I told a reader that there was no standard 555 circuit that could do this, but then the grey matter started working.
How does duty cycle work in a VCO?
Duty Cycle: Use this control or input to change the amount of time a square wave is high vs. low. A normal square wave is high and low for equal amounts of time, but you can also adjust it so that it has a short high pulse followed by a long low gap, or it could be high for most of the cycle and only drop low for a short time.
How to calculate the frequency of a CMOS oscillator?
The time period necessary for each half-cycle will be 1.1 x R x C, therefore the frequency can be presented as: where R is R2 and C is C1 in the circuit. Appropriate values for R2 resistor can be between 10 k and higher, and for capacitor C1 the value can be between 100 pF and higher.
How does a VCO keep an oscillator in sync?
Hard/Strong Sync: This input allows you to keep an oscillator (slave) in sync with another one (master). Connect the output of the master oscillator (some VCOs provide a pulse out for this purpose) into the sync input on the slave VCO and it will be forced to restart its cycle whenever the master does.