ADAU1701 mono peak limiter with ext. detector

https://ez.analog.com/message/42329#42329

Just saw in this thread from February 2012 that this feature is coming with the next release. Any idea when that would be?

The release build is scheduled for Thursday this week, but usually the web team takes a week or so to update the file on the download site, so I imagine it will be available at the end of next week.

Hi Brett,

Doesn't look like the download of SigmaStudio has been updated yet. Could you double check this?

I think the 3.7.3 beta on the website should cover these updates.

https://form.analog.com/Form_Pages/sigmastudio/SSDownLoad.aspx

I've been running 3.7.3 for about a month already. It has a mono peak limiter but with no external detector. I need one with external detection still.

Looks like 3.7.4 went up today but the change I've been asking for hasn't been included in the build.

The software manager is traveling on business, but I will bring this to his attention when he returns to the office.

Hi Brett,

Any news yet?

Thanks,

Shahin

Hi Shahin,

Sorry, but it looks like I had a misunderstanding here. It looks like this function was implemented for the 3rd generation cores, but not for the ADAU1701, which is 2nd generation.

I have sent a request to our algorithm developer to expedite a mono version of the peak compressor with external detect input, which, as you stated, is missing from the library:

https://ez.analog.com/cfs-file/__key/communityserver-discussions-components-files/396/c6d290d3e5c7fddeca441cda61fd73b6.html

In the meantime, I'm not sure if you'll have enough memory for this, but you could try the attached solution. It uses a peak envelope detector, logic cell, and a divider to implement a peak limiter with external detection input. I used ADC0 as the "detect" signal and ADC1 as the audio signal to be compressed.

If the input from ADC0 exceeds the threshold, then a gain of the Threshold divided by the Peak Level will be applied to the signal (effectively limiting it at the threshold level). The slew volume control can be adjusted to change the response time.

I updated the project for use with a simple mono input just so you can get a feel for how it works. I tried it with an actual audio source and it behaved as expected.

https://ez.analog.com/cfs-file/__key/communityserver-discussions-components-files/396/c10b9f8fdb7b5d4dbc0327187c356c65.html

The project is attached.

Hi Shahin,

I just got this response from the software algorithm developer:

I am planning to test this algorithm today. Not sure on the estimated date when it will be available for download.

The algorithm tested out fine and it has been included in the new SigmaStudio build. You will find it in the SigmaStudio 3.7.6 beta, as soon as it is available for download at www.analog.com/sigmastudiodownload.

Thanks Brett! I'll wait for the update to appear and test it out.

Doesn't look like this has be released yet. In the meantime, could you tell me how much memory the new mono limiter takes compared to the old stereo ext. input limiter?

My tests gave me the following results:

Stereo Peak Compressor, External Input (ADAU1701)

49 Program Instructions

10 Data RAM Words

35 Parameter RAM Words

Mono Peak Compressor, External Input (ADAU1701)

44 Program Instructions

9 Data RAM Words

35 Parameter RAM Words

This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

Thank you,
EZ Admin