Use FFT on sigma-delta ADCs

This application note covers two topics in digital signal processing and metering, namely the Fast Fourier Transform (FFT) and the sigma-delta analogue-to-digital converters (SD ADC).

Firstly, the FFT is a mathematical technique for transforming a time-domain digital signal into a frequency-domain representation of the relative amplitudes of the different frequency regions in the signal. The FFT is extremely important in the area of frequency (spectrum) analysis. Secondly, the SD ADCs are high resolution, high integration, and low cost ADCs for applications such as metering, process control and monitoring.

An in-depth introduction of both topics is outwith the scope of this application note, and some interested parties may find more details on relevant web pages or other sources. The main aim of this application note is to describe some methods for properly using the FFT in cooperation with the SD ADCs, especially in power metering applications.

View the PDF document for more information.

Originally published by Freescale Semiconductor at www.freescale.com as "Using an FFT on the Sigma-Delta ADCs".