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7
Tutorial
Pulse Width Modulation (PWM)
PWM is used in digital audio applications, motor control circuitry, switching power
supplies, and other control applications. The Keysight 33210A provides PWM for
pulse waveforms, and PWM is the only type of modulation supported for pulse
waveforms. For PWM, the amplitude of the modulating waveform is sampled
digitally and used to control the pulse width or duty cycle of the pulse waveform.
Pulse Width Modulation
The variation of pulse width in the modulated waveform from the pulse width of
the pulse waveform is called the width deviation. The deviation can also be
expressed in terms of duty cycle (as a percentage referenced to the period of the
pulse waveform), which is called the duty cycle deviation. In PWM the deviation of
width or duty cycle is symmetrical around the pulse width or duty cycle of the
original pulse waveform. For example, if you specify a pulse waveform with a 10%
duty cycle, and then specify PWM with a duty cycle deviation of 5%, the
modulated waveform will have a pulse that varies in duty cycle from 5% to 15%
under control of the modulating waveform.
360
Modulating Signal
Modulated Waveform
Keysight 33210A User's Guide
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