Tutorials

Sigma-Delta Analog to Digital Conversion Technology for Power Converters

Instructors

Prof. Jens Onno Krah, TH Köln, Germany

Rolf Richter, Intel/Altera, München, Germany

Duration

3 hours

Contents

More and more functions are realized with digital logic, e.g., FPGAs. With sigma-delta (SD) technology, most of the signal processing is fully digital and only limited analog circuitry is required. This improves immunity to electromagnetic interference, increases flexibility through better configurability and is also more cost effective.

In this tutorial, the basics of sigma-delta are explained and a current measurement application is built using a shunt, a 2nd order sigma-delta modulator and an Intel/Altera FPGA is put into practice as part of a VHDL on-line demo with (limited) audience interaction.

1. SD based Digital to Analog Conversion

2. SD based Analog to Digital Conversion

3. Decimation Filtering

4. Current Measurement Applications

· Sampling technics

· PWM-synchronization

· Shunt leakage inductance compensation

· Open Loop Hall transducer with SD Interface

· Current observer

· High frequency current waveform analysis using Discrete Fourier Transformation (DFT)

· Electronic fuse

· DC link rms current estimation

· Functional Safe (FuSa) current acquisition

5. Other Applications

· Resolver to Digital Conversion (RDC)

· Functional Safe RDC