Analog techniques have dominated signal processing for years, but digital techniques are slowly encroaching into this domain. The design of delta-sigma (ΔΣ) analog-to-digital converters (ADCs) is approximately three-quarters digital and one-quarter analog. ΔΣ ADCs are now ideal for converting analog signals over a wide range of frequencies, from DC to several megahertz. Basically, these converters consist of an oversampling modulator followed by a digital/decimation filter that together produce a high-resolution data-stream output.
This two-part article will look closely at the ΔΣ ADC’s core. Part 1 will explore the basic topology and function of the ΔΣ modulator, and Part 2 will explore the basic topology and function of the digital/decimation filter module.