ADC Guide, Part 1: the ideal analog/digital converter

Analog-to-digital converters (ADCs) are one of the most commonly used blocks in embedded systems. Applications of ADCs include current sensing, motor control, temperature sensing and a myriad of others. As a consequence, understanding the basic specifications of an ADC and selecting an appropriate device for the given application is a must for reliable operation and cost-effective design.

This series of articles will begin with the basics of ADCs, and then discuss different characteristics of an ADC that are important to design, including the impact of various irregularities, types of ADCs available on the market, advantages and disadvantages of each type, and how their selection varies from application to application. This first part of this article series discusses what exactly an ADC is and how an ideal ADC works. In the subsequent articles, we will go to more practical aspects and parameters of an ADC.

To read Part 1 of the series, which is presented as a pdf document, click here .

About the authors

Sachin Gupta is a Senior Applications Engineer in the Global Applications team at Cypress Semiconductor Corp. He can be reached at .

Akshay Phatak is an Applications Engineer with Cypress Semiconductor. He holds a Bachelor's degree in Electronics and Telecommunications form College of Engineering, Pune (India). He likes to work on mixed-signal embedded systems. He can be reached at .

5 comments on “ADC Guide, Part 1: the ideal analog/digital converter

  1. SunitaT
    March 19, 2013

    Sachin and Akshay, thanks for the detail description on the ADC.
    1LSB is equal to VFs / 2^N, it stands to reason that better accuracy (lower error) can be realized if we use a higher resolution and/or use a smaller input voltage. The problem with higher resolution (more bits) is the cost. Also, the smaller LSB means it is difficult to find a really small signal as it becomes lost in the noise, reducing SNR performance of the converter. The problem with reducing the input voltage is a loss of input dynamic range. Again, we also can lose a small signal in the noise, causing a loss of SNR performance.

    One suggestion, it will be great help if you can add all the links of the previous posts on ADC guides in your upcoming posts (like “Related posts”).

  2. amrutah
    March 19, 2013

    I agree with SunitaT, if the links to all the parts of the ADC series 1-13 and further are available at one place then it will be helpful.

  3. amrutah
    March 19, 2013

    @sunitaT: To add to your point, “the smaller LSB means it is difficult to find a really small signal as it becomes lost in the noise…”. 

    Higher resolution will lead to many constraints on the quantiser, the offset of the quantiser will become comparable.  The memory requirements will increase.  Do you see any further complexities???

  4. Brad Albing
    March 19, 2013

    I'll try to get those links added. But in the meantime, use the search function (upper right) and search on either of the authors' names or “ADC Guide” – that should point you to the other posts.

  5. Brad Albing
    March 19, 2013

    I'm working on it!

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