TLV320AIC3204: How to detect input clipping for both SE and DI input?

Hi,

You can add a resistor divider to ensure the input does not exceed the limit.

The device supports DC measurement if the ADC channel is not used for any audio recording, see section 2.3.3.2.4 in this document.

https://www.ti.com/lit/ml/slaa557/slaa557.pdf?ts=1661291491174&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTLV320AIC3204

Regards.

Thanks very much. The ADC will be used for audio input, and sadly I can't control what the input is, as it's up to the end user. So it seems that these solutions will not work unfortunately.

I'd like a way to reliably tell them their input is too high, which is a pretty common feature. Worst case the user needs to specify balanced or unbalanced, but that shouldn't be necessary.

Ya unfortunately there's no other indicator/flag. The user needs to know they can't not exceed the max input allowed and the type of configuration.

Regards.

Thanks.  Unfortunately we can't ask much of the users, they'll just plug it into whatever and expect it to work, then complain when they hear distortion.  If we can't give them an indicator that their levels are too high, which is very common on hardware like mixers and such, they won't know it's their problem.

I wish there was some kind of detect to see if anything pre-ADC was saturated.  It's a shame it's not included in the chip.

I suppose one workaround is to set the clip-detect threshold to what it would be for a single-ended input, but that sacrifices dynamic range/bit resolution in the differential mode.

Flags/interrupts for this part are mentioned in section 2.11.2 of the reference guide, maybe you can work around the events mentioned there.

Thanks.  It doesn't look like any of that will help.  Sadly the AGC operates after the DAC, so that also won't work.  I don't see a solution to this.

Unfortunately those are all interrupts available for this from software side or as suggested earlier modify the hardware.

I don't see how modifying the hardware will help.  We have no control of what the user connects.  We can of course make any arbitrary input range, but eventually this leads to excessive noise if the valid range is too large.  It's amazing how much excessive output some devices deliver.

I was hoping there was a clever way to do this, but perhaps there is not.

I don't know your design, but the input requirements are specified in the datasheet. 

DC measurement and placing a resistor divider are suggested options, if this is not possible then there's no other software option to accomplish this.

I appreciate the response, but I think we're not really understanding each other.

1. I'm not sure how DC measurement would help in this case.  Audio inputs are capacitively coupled, and the channel is indeed used for audio input, so it's unavailable for other purposes.

2. A resistor divider already exists, but altering it won't help.  It will change the valid voltage range of inputs of course, but I have no control of what the end-user chooses for levels.  The goal is to alert the user when they are feeding an excessive signal, which is a fairly common indicator on professional-grade products.

In that case, there's no sw solution to this.