Pulse width modulation (PWM) is a modulation technique that is used to encode a message into a pulsing signal. PWM controllers encode data onto the duty cycle (the ratio or percentage of one period in which a signal or system is active). The encoded data is commonly used in power electronic systems to regulate the amount of power applied to the load.
A PMC will use voltage feedback to ensure that the voltage applied to a load is precisely controlled. The controller will supervise the switching operation to regulate the output voltage by comparing output voltage with the desired output to derive the correct voltage. They are popular because of their high efficiency over a wide voltage input range.A PWM controller can also be integrated with a hot swap controller for enhanced power monitoring accuracy.
PWM controllers are common in many applications including variable speed fans, house dimmer switches and electric cookers.