1 2 3 4 Previous Next

Analog Dialogue

55 posts

Can you explain why the minimum and maximum gain errors specified by my ADC differ so much? Learn more in "Isn’t that gain specification a bit lopsided?" as published in the March 2015 issue of Analog Dialogue.

 

A-D 49-03 RAQ.jpg

 

We welcome your feedback. Has this article helped you in your design? Would you like more information on this topic?

 

Best regards,

Scott

Do I really need to match the impedance between both inputs of my amplifier? Learn more at "Muntzing can save cost, components, and even your sanity" as published in the April 2015 issue of Analog Dialogue.

A-D 49-04 RAQ.jpg

 

 

We welcome your feedback. Has this article helped you in your design? Would you like more information on this topic?

 

Best regards,

Scott

analogkidr

Choosing References

Posted by analogkidr Feb 6, 2015

How do I choose a voltage reference? Learn more at "Choosing References" as published in the February 2015 issue of Analog Dialogue.

 

A-D 49-02 RAQ.jpg

We welcome your feedback. Has this article helped you in your design? Would you like more information on this topic?

 

Best regards,

Scott

 

My amplifier doesn’t behave properly when multiplexing channels. What could be the cause? Find out in "Don't Get Caught Speeding" as published in the January 2015 issue of Analog Dialogue.

A-D 49-01 RAQ.jpg

We welcome your feedback. Has this article helped you in your design? Would you like more information on this topic?

 

Best regards,

Scott

How can a high-performance analog-to-digital converter have numerous power connections but only a couple of grounds? Find out at "Exposed Paddles and Downbonds Improve Performance and Reduce Pin Count" as published in the December 2014 issue of Analog Dialogue.

A-D 48-12 RAQ.jpg

We welcome your feedback. Has this article helped you in your design? Would you like more information on this topic?

 

Best regards,

Scott

analogkidr

Choosing Analog ICs

Posted by analogkidr Feb 6, 2015

You’ve told us that we need not be too careful when choosing discrete transistors. What about analog ICs? Learn more in "Choosing Analog ICs", as published in the November 2014 issue of Analog Dialogue.

A-D 48-11 RAQ.jpg

We welcome your feedback. Has this article helped you in your design? Would you like more information on this topic?

 

Best regards,

Scott

What should concern me when testing my heart-rate monitor prototype? Find out in "I Grew Up in the 80s and Survived! " as published in the October 2014 issue of Analog Dialogue.A-D 48-10 RAQ.jpg

We welcome your feedback. Has this article helped you in your design? Would you like more information on this topic?

 

Best regards,

Scott

I need 100-dB dynamic range for a medical imaging application. Can you help me choose between successive-approximation and sigma-delta ADC architectures? Find out more in ADCs for High Dynamic Range – Successive-Approximation or Sigma-Delta? as published in the September 2014 issue of Analog Dialogue.

A-D 48-09 RAQ.jpg

We welcome your feedback. Has this article helped you in your design? Would you like more information on this topic?

 

Best regards,

Scott

We live in an interconnected world where we get a cup of coffee, listen to music, heat our lunch, all on a push of a button. The millenials have taken over! The world of instant gratification is here, where we want things to happen instantaneously. So that got me thinking......what would it feel like to have this instant gratification when a systems architect is designing a heterodyne receiver with an ADC and some associated components. Now, that is a different cup of coffee y'all.

 

Analog Devices Inc. (ADI) has always prided itself in providing industry leading performance in Analog-Digital Conversion. There are two ways to see this in action:

  1. Read the datasheet and blindly "trust" the numbers, or
  2. Get an evaluation system for yourself and find it out (if you are the old school type where "seeing is believing")

 

Now, what if.......just what if the hardware you bought was not what you were looking for. Now you have hundreds of dollars worth of boards in your lab, that you essentially don't want. Try explaining that your boss.

 

There however, exists a third method. This method is behavioral modeling and it is gathering steam. ADI has been providing behavioral models for ADCs and other products for a long time, but this in my opinion has been under-utilized. In order to utilize the behavioral models for ADCs one only needs to download and install our free tool VisualAnalog. VisualAnalog is a versatile tool that helps systems architects determine which ADC they would want in their system. VisualAnalog is usually marketed as a tool to evaluate ADCs, which is true. An added benefit to VisualAnalog is that you really do not need to buy hardware to evaluate ADC performance. This is because of the behavioral modeling tool within VisualAnalog called ADISIMADC. See below for a comparison of ADISIMADC and actual performance of AD9467, our highest dynamic range ADC to date. Figures 1 and 2 show the measured and simulated performance of the AD9467 evaluation board when clocked using a Rohde & Schwarz SMA100A with B22 low phase noise option.

ad9467_97MHz_filtered.jpg

Figure 1: Measured performance from Evaluation Board of AD9467 at 97MHz analog input

adisimadc_97MHz.png

Figure 2: Simulated performance of AD9467 at 97MHz analog input

 

Now if you choose to use an ADI clocking solution, the combined performance can be simulated by spending a grand total of $0! This is because there is a behavioral modeling tool called ADISIMCLK that can simulate clock performance. The information from ADISIMCLK can be passed on to the ADISIMADC model within VisualAnalog and the performance of the AD9467 (for example) can be simulated with the AD9523 (for example) clocking it. If you dont like what you see, you can select another ADC, or clocking device. For free! How about that!

 

Figure 3 below shows how closely ADISIMADC predicts the SNR performance of the AD9467 across input frequency when driven using the AD9523.

measured_data_modified.png

Figure 3: Simulated vs. measured performance of AD9467 + AD9523 across frequency


I have always wondered if modeling tools will gain the trust of systems designers in helping them choose the appropriate ADC and clocking chip. I think the suite of tools from ADI is definitely a step in the right direction to help him make that decision without a major investment in evaluation boards. Here is where I discuss this problem in detail.

ADC Modeling Tools Speed Up Evaluation

 

We can learn a thing or two from a millenial after all......

 

Ciao

Umesh

 

11/08/2014 Edit:

- changed figure 2 to match the same conditions as figure 1

- provided link to VisualAnalog

analogkidr

The Diamond Plot

Posted by analogkidr Jul 10, 2014

Your signal is within the instrumentation amplifier's specified input voltage range, but the output is saturated. Find out what's happening in The Diamond Plot, as published in the July 2014 issue of Analog Dialogue.


A-D 48-07 RAQ.jpg

We welcome your feedback. Has this article helped you in your design? Would you like more information on this topic?

 

Best regards,

Scott

High-channel-density data-acquisition systems used for medical imaging, industrial process control, ATE, and 40G/100G optical communication systems multiplex signals from many sensors to a small number of ADCs. This article focuses on key design, performance, and application challenges of multiplexed data-acquisition systems using high-performance precision SAR ADCs.

AD4807-01-Fig1[1].png

You can read the entire article titled: "Demystifying High-Performance Multiplexed Data-Acquisition System" as published in the July 2014 issue of Analog Dialogue.

 

I would love to hear any feedback or comments on this article or this topic in general. You can leave your feedback in the comment section below.


Best Regards,

Maithil

New chip scale isolation technologies are now enabling smaller, cheaper and more reliable isolated data interfaces. For example isolating an I2C/PMBus interface with ADIs’ iCoupler and isoPower technologies enables new single chip, I2C/PMBus interface.

In my article I look at the traditional methods of implementing an isolated I2C/PMBus interface using discrete components based on opto-couplers for signal isolation and discrete transformer for power isolation. I then show how new chip scale isolation technology, is enabling new single chip isolated I2C/PMBus interface links that significantly reduce design time and provide compact, reliable, low-cost, high performance solutions. I show a new, fully isolated I2C/PMBus isolator in the article, the ADM3260.

You can read the entire article titled Designing Robust, Isolated I2C/PMBus Data Interfaces for Industrial, Telecommunications, and Medical Applications in this month's issue of Analog Dialogue.

I would love to hear any feedback or comments on this article or this topic in general. You can leave your feedback in the comment section below.

Thanks


-Maurice.

MEMS accelerometers offer easy integration and reduced cost to an emerging class of vibration monitoring applications. In addition to the many attractive attributes of the core sensors (size, power, multi-axial, analog and digital options, etc), more advanced solutions, such as the ADIS16229, provide a more complete solution that includes signal processing and communications. This type of programmable device can wake itself up periodically, capture time-domain vibration data, perform a Fast Fourier Transform (FFT) on the data record, apply user-configurable spectral analysis on the FFT result, offer simple pass/fail results over an efficient wireless transmission, provide access to data and results, and then go back to sleep.

MEMS_Vibe_FFTwAlarms.png

New adopters of vibration sensing are finding that quick deployment and reasonable cost of ownership are good reasons to evaluate fully integrated MEMS devices.  For this reason, many engineers are considering MEMS solutions for new vibration applications.  For this reason, we decided to write an introductory article that describes the basic functions in a MEMS vibration sensor along with some key application-level functions. 


Click on the following title to access the online version of An Introduction to MEMS Vibration, which just reached publications.  We hope that this article is helpful and look forward to your comments.

Current mirrors and current sources offer advantages in a number of situations, including analog current-loop signaling in high-noise environments and level shifting an analog signal across a large potential difference without the use of optical or magnetic isolation techniques. Find some techniques and useful circuits in Current-Output Circuit Techniques Add Versatility to Your Analog Toolbox, as published in the April 2014 issue of Analog Dialogue.

4804-2-FIG05.jpg

We welcome your feedback. Has this article helped you in your design? Would you like more information on this topic?

 

Best regards,

Scott

I see a lot of ringing and overshoot at the output of my amplifier. What could I be doing wrong? Get some troubleshooting tips at Looking for Trouble in All the Wrong Places, as published in the April 2014 issue of Analog Dialogue.

A-D 48-04 RAQ.jpg

We welcome your feedback. Has this article helped you in your design? Would you like more information on this topic?

 

Best regards,

Scott

Filter Blog

By date:
By tag: