AN1827/0304

1/11

Rev. 1.0

AN1827

APPLICATION NOTE

IMPLEMENTATION OF SIGMA-DELTA ADC

WITH ST7FLITE05/09

INTRODUCTION

The purpose of this document is to describe how to implement a 10-bit Sigma-Delta A/D con-

verter using a simple external circuit and a Sigma-Delta conversion program.

The external Sigma-Delta ADC described in this application is designed for relatively slow al-

ternating signals (0,2 - 5Hz) in the range 0 - 10mV(p-p). The focus of the project is to provide

good relative accuracy, repeatable parameters and simplicity, resulting therefore a low cost of

the device (in its simplest form, apart from the microcontroller, only three RC elements are

necessary).

1