Online RC Lowpass filter Calculator
Figure1 shows a lowpass filter made from a RC section, It's cutoff frequency is shown below
formula 1
Figure 1
Figure2 is a lowpass filter using a single opamp, and a single power supply. C2 is a capacitor with high capacity. The voltage amplification factor of this circuit is R1/R2. The cutoff frequency of figure 2 is same with figure 1
Figure 2
Figure 3 is a simulation result When R1=R2=15915Ohm, C1=10nF (The cutoff frequency is 1K). Gain=1, 0.707V is cutoff frequency point
Figure 3
Input C1, R1 to calculate cutoff frequency F:
| Capacitor C | ||
| Resistor R | ||
| Cutoff Frequency f | ||
Input C1, cutoff frequency F to calculate R1:
| Capacitor C | ||
| Cutoff Frequency f | ||
| Resistor R | ||