PWM stands for P ulse- W idth M odulation. Once the switching frequency (f sw ) has been chosen, the ratio between the switch-on time (T ON ) and the switch-off time (T OFF ) is varied. This is commonly called duty-cycle (D). The duty cycle can be between 0 and 1 and is generally expressed as a percentage (%). D = T ON / (T ON + T OFF ) = T ON x f sw The variation of the pulse width, made at a high frequency (kHz), is perceived as continuous and can be translated into a variation of the rotation speed of a motor, dimming a LED, driving an encoder, driving power conversion, and etc. The use of PWM is also widely used in the automotive sector in electronic control units (ECU - Electronic Control Unit) to manage the energy to be supplied to some actuators, both fixed and variable frequency. A ...