Main Content

ADC Tutorial

Open Live Script

Introduction

This tutorial example shows you how to design a second order Delta Sigma Analog to Digital Converter in Simulink®. Start with a simple system-level design of a first order delta sigma ADC, and progressively refine its design.

In the first section, you will design a system-level model of DSM ADC. In the second section, you will generate SystemVerilog module, cosimulate the Simulink® testbench and the filter implementation with Cadence Incisive®. You will conclude this tutorial by putting together the final system-level model of the ADC.

Architecture

The ADC system consists of three components:

  • the analog anti-aliasing filter,

  • the delta sigma (ΣΔ) converter,

  • the digital multi-rate multi-stage decimation filter.

A system-level block diagram of an ADC is shown below, in Figure 1.

The analog filter constraints the bandwidth of the input signal, so that when it is sampled at a fixed rate, eventual higher frequency components are eliminated and do not cause aliasing.

The sigma-delta converter operates at a high sampling rate, and generates an oversampled digital representation of the Analog data. The output is a two-level signal that toggles with a frequency that is proportional to the amplitude of the input signal.

The digital filter reduces the data rate of the discretized signal by applying decimation. It creates a higher resolution but lower sample rate digital output which represents the desired signal.

Contents

The tutorial consists of three sections:

Each section continues where the prior section left-off. As a result, you might want to work through each section of the tutorial in a sequence. To get started, please review the product requirements (outlined below), and then begin with System-level model.

Required Products

To complete the first step of this tutorial, you need the following MathWorks products:

  • MATLAB

  • Simulink

  • Signal Processing Toolbox

  • DSP System Toolbox

To complete the second and third steps of this tutorial, you also need the following MathWorks products:

  • Simscape

  • Simscape Electrical

  • Control System Toolbox

  • Simulink Control Design

To complete the fourth step of this tutorial, you also need the following MathWorks products:

  • Fixed-Point Designer

  • HDL Coder

  • HDL Verifier

To complete the cosimulation step, you run the model using the Linux operating system, and you need a running installation of Cadence Incisive or Cadence Xcelium.

  • Cadence Incisive™

  • Cadence Xcelium™

At last, to measure the DC and AC characteristics of this ADC you use the ADC measurement testbech from Mixed-Signal Blockset.

  • Mixed-Signal Blockset

______________________________________________________________________________

Copyright© 2019-2024 The MathWorks, Inc. All rights reserved.