What Is the Inverting Op-Amp Active Low-Pass Filter Calculator?
The Inverting Op-Amp Active Low-Pass Filter Calculator models frequency response, corner frequencies, and amplification for active analog filter circuits.
How Does the Inverting Op-Amp Active Low-Pass Filter Calculator Work?
It computes DC inverting gain from the resistor ratio and determines the pole location set by the feedback parallel RC combination.
Inverting Op-Amp Active Low-Pass Filter Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Complex frequency s-domain impedance ratio Z_f(s) / Z_in(s) for feedback-stabilized operational amplifiers.
How to Use the Inverting Op-Amp Active Low-Pass Filter Calculator
- Specify input resistor R₁ and feedback resistor R₂ in kΩ.
- Enter feedback capacitor C₁ in nanofarads.
- Input operating evaluation frequency in Hz.
Step-by-Step Example Calculation
1 kHz Audio Anti-Aliasing Active Filter
Input Values:
Understanding Your Result
Cutoff Frequency: Corner frequency where signal power drops by 50% (-3 dB).
DC Voltage Gain: Low-frequency amplification factor in linear V/V and decibels.
Gain at Test Frequency: Actual output level at the specified operating point.
Factors That Affect the Result
- Larger feedback capacitors push the cutoff frequency lower into the audio/sub-audible spectrum.
- Higher R₂ values increase passband gain but narrow open-loop bandwidth.
When Should You Use This Calculator?
- Sensor signal conditioning, ADC anti-aliasing filters, audio tone shaping, and biomedical ECG instrumentation.
Assumptions & Limitations
- Assumes ideal op-amp behavior within the device Gain-Bandwidth Product (GBWP) and slew rate limits.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Based on Franco Design with Operational Amplifiers and Analog Integrated Circuits.