I2S Dac audio with volume control

Carlos Patino

Other Parts Discussed in Thread: PCM5121, PCM5101A, PCM5101

Hi, actually we are using the PCM5101APWR to convert I2S audio into an analog output. Our main problem its our new requirement, this device its a handled device so we need to have volume control into the audio.

We are looking for a IC like the PCM5101APWR but with a volume control throught I2C or GPIO. We need it to be simple, as we dont configure the input/outputs/data rate.... etc.

This its our audio architecture actually.

As you can see, we need the I2S dac to have any kind of volume control.... or we could use another IC on the middle to control it. Any suggestion IC or ideas?.

Regards, Carlos.

over 4 years ago

0 Paul_Frost over 4 years ago

TI__Guru 53973 points

Hi Carlos,

You could consider the PCM5121. This is the same analog performance as the PCM5101A, but features an I2C/SPI interface that allows for volume adjustment and some other features.

Thanks,

Paul

0 Carlos Patino over 4 years ago in reply to Paul_Frost

Prodigy 40 points

Hi Paul, thanks for the answer.

I read this datasheet just in the evening. Could i use this PCM5121 without touching any register?. I mean, could i use it with the default configuration with the same result as the PCM5101 but touching only the volume registers to obtain a volume control?.

If it is correct, i would start ASAP to modify the schematic to the new prototype board.

0 Paul_Frost over 4 years ago in reply to Carlos Patino

TI__Guru 53973 points

The device can automatically configure it's clock tree if the I2S input clock ratios are standard and you are using 4-wire I2S mode.

If you are using 3-wire I2S, you will need to configure the device manually if you have the device in I2C or SPI mode. If you have the PCM5121 configured for HW mode, it will automatically accept 3-wire data.

Thanks,

Paul

0 Carlos Patino over 4 years ago in reply to Paul_Frost

Prodigy 40 points

Hi Paul, thanks again. I am asking to our HDMI bridge solution if their I2S its in a 4 wire format.

If it is on 3wire format we should understand how to configure it, did you have some lilterature on this side?.

Thanks for the support Paul.

+1 Paul_Frost over 4 years ago in reply to Carlos Patino

TI__Guru 53973 points

Section 8.3.6.1 of the PCM5121 datasheet reviews the clock configuration procedure.

Thanks,

Paul

0 Carlos Patino over 4 years ago in reply to Paul_Frost

Prodigy 40 points

Thanks paul, i modified the schematic design with this new IC you recommend us. We are using the 4Wire mode, so it will work without any problem i guess.

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I2S Dac audio with volume control