RC High-Pass Filter Calculator
First-order passive RC high-pass: get the cut-off from R/C or back out the components from a target f_c, with attenuation and phase at a probe frequency.
Key points
RC High-Pass Filter Calculator: First-order passive RC high-pass: get the cut-off from R/C or back out the components from a target f_c, with attenuation and phase at a probe frequency. Formula: f_c = 1/(2πRC) ｜ |H| = (f/f_c)/√(1+(f/f_c)²). Enter parameters on the DD-CAT IDE online tool page to get results instantly, with a calculation-model diagram that updates with the inputs. A passive first-order high-pass rises 20dB per decade and attenuates the passband by R/(R+1/ωC); the next stage must have an input impedance well above R. The output is across R; taken across C it becomes a low-pass.
Inputs
f_c = 1/(2πRC) ｜ |H| = (f/f_c)/√(1+(f/f_c)²)Calculation model (updates with parameters)
Bode plot (magnitude / phase, updates with parameters)
| Cut-off f_c | 1.592 kHz | |
| Resistor R | 1 kΩ | |
| Capacitor C | 100 nF | |
| Time constant τ | 100 µs | |
| 观察频点 1 kHz 的衰减 | -5.48 dB（0.5320×） | |
| Phase at that frequency | 57.9° | +45° at f_c, approaching 0° well above it |
| Rise time (10–90%) | 220 µs | The low-pass view of the same τ; a high-pass strips the slow component |
Engineering notes
- A passive first-order high-pass rises 20dB per decade and attenuates the passband by R/(R+1/ωC); the next stage must have an input impedance well above R.
- The output is across R; taken across C it becomes a low-pass.
FAQ
- What is RC High-Pass Filter Calculator for?
- First-order passive RC high-pass: get the cut-off from R/C or back out the components from a target f_c, with attenuation and phase at a probe frequency.
- What is the formula for RC High-Pass Filter Calculator?
- Core formula: f_c = 1/(2πRC) ｜ |H| = (f/f_c)/√(1+(f/f_c)²). The tool returns results instantly using this formula and the selected parameters.
- What engineering notes should I keep in mind when using RC High-Pass Filter Calculator?
- A passive first-order high-pass rises 20dB per decade and attenuates the passband by R/(R+1/ωC); the next stage must have an input impedance well above R. The output is across R; taken across C it becomes a low-pass.