A ΣΔ A/D converter realized by using ST52X440 microcontroller

In the paper the realization of a first order sigma-delta A/D (analog-to-digital) converter and of the software tools developed for its characterization are introduced. The A/D converter is based on the use of ST52X440 microcontroller produced by ST Microelectronics by exploiting both the availability of a comparator for the realization of the high frequency loop and its computing capability for the realization of the digital filters. A description of the hardware solutions and of the filtering blocks for the implementation of the sigma-delta converter is given. A software tool implemented in LabVIEW® by National Instruments™ that realizes a custom interface for the device characterization is also described. Preliminary results suggest satisfactory performance of the device and allow to foresee interesting application in low cost sensing devices.