RC Low-Pass Filter Design for PWM Calculator
RC low-pass filters are essential for smoothing PWM signals, reducing noise, and enhancing signal quality. Our calculator simplifies the design process, ensuring optimal performance.
- Enter the PWM frequency in Hertz.
- Enter the desired duty cycle in percentage.
- Enter the allowed ripple percentage.
- Click ‘Calculate’.
The calculator uses the following formula to determine the filter components:
R = (Vcc * (1 - D)) / (2 * f_c * L)
C = 1 / (2 * π * f_c * R)
where Vcc is the supply voltage, D is the duty cycle, f_c is the cutoff frequency, L is the inductance, R is the resistance, and C is the capacitance.
| PWM Frequency (Hz) | Resistance (Ω) | Capacitance (F) |
|---|---|---|
| 1 kHz | 100 | 10 nF |
| 10 kHz | 10 | 1 nF |
| 100 kHz | 1 | 100 pF |
- Choose a cutoff frequency (f_c) at least 10 times lower than the PWM frequency.
- Use low-ESR components to minimize losses.
- Consider using a common-mode choke to further reduce noise.
What is the difference between a low-pass filter and a high-pass filter?
A low-pass filter allows low-frequency signals to pass while attenuating high-frequency signals. A high-pass filter does the opposite.