TLV320AIC3104: How to pass through LINE1L to Lout while recording and limit output voltage by AGC function?

Jerry Yang

Part Number: TLV320AIC3104

Hi Ti team,

We are now trying to make LINE1L output to Lout directly while recording and here is the input/output signal spec for our application:

1. Line1L: 5~750 mVrms

2. LEFT_LOP/LEFT_LOM: 250~750 mVrms

The problems we facing are:

1. Could we output the Line1L signal to left out through "PGA_L" by open register 81? What's else should be setup at the same time?

2. From the input spec provided, if we hope to maintain and limit the output voltage at 750 mVrms with all input voltage (5~750 mVrms), is it possible by setting AGC function to fulfill that?

Please help to check the questions above, thanks.

BRs,

Jerry

over 4 years ago

0 pdjuandi over 4 years ago

TI__Mastermind 29765 points

Hi Jerry,

1. Yes you can use the PGA direct path by configuring the register shown in the diagram. For example besides R81 you need to set R19, R22, R15 etc.

2. I think it's possible.

Regards,

Peter

0 Jerry Yang over 3 years ago in reply to pdjuandi

Prodigy 20 points

Hi Peter,

Thanks for the reply. For question 1, we have done the implementation on this function. Now each Line1L/R could pass through L/Rout smoothly.

However, for the AGC configuration, we are still not quite clear about the correlation between target level and output voltage. Could you help to provide some further description on how to calculate the target level of AGC or maybe there is a document we could refer to?

If it is possible, using our spec as a example would be even better. (if input=5 or 750mV, how to calculate target level and limit output at 750mV?)

Thanks & BRs,

Jerry Yang

0 pdjuandi over 3 years ago in reply to Jerry Yang

TI__Mastermind 29765 points

Hi Jerry,

Here is an apps. note with example on AGC, this applies to AIC3104 as well.

https://www.ti.com/lit/an/slaa446/slaa446.pdf?ts=1635780155533&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTLV320AIC3120

Regards,

Peter

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TLV320AIC3104: How to pass through LINE1L to Lout while recording and limit output voltage by AGC function?