Pwm filter circuit and related control system

A control system, comprising:

• a control device, configured to generate a PWM signal;
• multiple filter circuits, configured to couple with the control device, wherein each of the multiple filter circuits is configured to receive and filter the PWM signal;
• and
• multiple output devices, wherein each of the multiple output devices is configured to correspondingly couple with one of the multiple filter circuits, and to conduct operations according to the PWM signal;
• wherein each of the multiple filter circuits has a predetermined threshold value, the filter circuit compares a duty ratio of the PWM signal with the predetermined threshold value, when the duty ratio of the PWM signal is larger than the predetermined threshold value, the filter circuit outputs the PWM signal to one of the multiple output devices correspondingly couples with the filter circuit, and when the duty ratio of the PWM signal is smaller than the predetermined threshold value, the filter circuit does not output the PWM signal to the one of the multiple output devices correspondingly couples with the filter circuit.