What are Digital Filters? (Moving Average, Butterworth, Kalman)

Digital FilterMoving AverageButterworthSignal ProcessingDSP

What are Digital Filters?

Digital filters are mathematical algorithms used to remove unwanted components (noise, interference) from a signal after it has been digitized (post-ADC).

Common Filter Types

1. Moving Average

The simplest and most common filter. It takes the average of the last N measurements.

  • Pro: Excellent at suppressing random noise (white noise).
  • Con: As N increases, the system's response time slows down. It creates lag in fast-changing signals.

2. Butterworth (Low Pass)

Used to cut off all vibrations above a certain frequency. Since its frequency response is "flat", it cleans high-frequency interference without distorting the signal's original character.

3. Kalman Filter

It doesn't just look at the current measurement; it predicts "what the next value should be" based on the system's physical model. It finds the most accurate result by weighting the difference between the measurement and the prediction.

Amazeng GDT and ZMA Series feature multi-stage adaptive digital filters adjustable by the user.

Technical Terms Glossary Back to