3 Conclusion
PWM signals can be transformed into analog signals using a simple RC type low-pass filter. The PWM duty cycle determines the magnitude of the filter’s voltage output. As the duty cycle increases, the average voltage output increases, and vice versa. The PWM frequency determines the amount of attenuation the filter can produce. When the PWM frequency is close to the cut-off frequency, the filter responds quickly, but produces a high amount of ripple in the output signal. As the distance between the cut-off frequency and PWM frequency increases, the response time decreases, but the ripple in the output signal also decreases.