PWM stands for Pulse Width Modulation. Electronic circuits can contain both analogue and digital components. PWM allows you to control analogue devices using a digital signal. Many electrical designs use PWM for regulation.
Analogue signals can be on or off, but they can also be half-way on etc. Whereas a digital signal has just on or off positions. Both signals appear in electronic circuits and are required to work together. Inputs can be converted using a DAC or ADC. PWM is available to control the output of a device. For example, a PWM can convert the digital output of a microcontroller (MCU) into an analogue signal, to drive the next analogue component.
Types of PWM device:
PWM Voltage Mode Controllers work by applying a control voltage (Vc) and a PWM ramp (Vramp) input.
PWM Current Mode Controllers add a second loop feeding back to the inductor current to create the PWM ramp.
PWM Switching Regulators feed the input voltage back through the PWM controller to keep the output voltage constant.
What is duty cycle?
PWM signals feature two main things, frequency and a duty cycle. Duty cycle is given as a % and refers to the amount of time the signal is on. For example, if the duty cycle is 50%, the signal is on for 50% and off for 50% of the time period. Pulse width modulation uses a rectangular pulse wave.
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