TAS5782M: Inquiries about AC Coupling, Dithering, Mute, and the Programmer

Imad Shaham

Part Number: TAS5782M
Other Parts Discussed in Thread: PUREPATH-CMBEVM

Tool/software:

Hi,

I'm working on a Class-D Amplifier based on the TAS5782M, which I'm going to control its registers using an STM32 MCU over the I2C communication protocol. I've the following questions:

1) The EVM board uses MLCC capacitors for the AC coupling between the DAC_OUT pins and the SPK_IN+ of the amplifier, and the SPK_IN- to the ground. I want to replace the MLCCs with aluminum electrolytic capacitors for higher audio quality, the question is related to the polarity of these caps; as I'm wondering whether there is an internal DC bias at the DAC_OUT or SPK_IN pins that requires careful attention to the polarity. (I'm using BTL Mode).

2) The registers sheets mention the terminology "dithering", which I would like to know more about, and how it affects the audio quality, furthermore, what are AC/DC/DEM dithering, and what should I do with these registers? (a detailed answer would be appreciated).

3) In register 0x08, what does MUTE Control Enable do, what are the PCM to TPA modes?

4) Is there any way to program the TAS series of smart amps directly using a USB to I2C converter? does the PPC3 software generate a hex file or so, which can be used to upload the code to the TAS without using the PUREPATH-CMBEVM board? because I noticed that the PUREPATH-CMBEVM uses the TAS1020BPFB which is an Obsolete part.

Best Regards.

7 months ago

0 Jesse Ji 7 months ago

TI__Mastermind 20431 points

hi,

1. yes, i remember there is the dc bias at the spk_in, you can check the signal with the oscilloscope.

2&3. let me confirm with team, and reply you by this week.

4.yes, ppc3 can generate .h filer, you can use that file config by i2c directly.

/cfs-file/__key/communityserver-discussions-components-files/6/How-to-generate-config-script-from-ppc3.pdf

thanks

jesse

0 Jesse Ji 7 months ago in reply to Jesse Ji

TI__Mastermind 20431 points

hi,

sorry for replying you late.

about q2, as this device is a little to old. i haven't found very detail doc.

but we know it should affect the output THD and idle noise level.

we usually do not recommend customer changing that as we haven't do the test with those settings.

you can take a try using those registers to see output thd and idle noise whether can meet your request better.

about q3, i am very sorry that this bit seems haven't be active.

i tried config this bit, nothing happened. we will let team remove this bit description as it hasn't really be used.

thanks

jesse

0 Imad Shaham 7 months ago

Prodigy 40 points

Thank you for your clarification, I've requested the PPC3 software to use the evaluation board, however my request got denied, I couldn't configure the audio source of the purepath motherboard without having it, so can you please help me to get the PPC3 software with the TAS5782M GUI. Best Regards!

0 Jesse Ji 7 months ago in reply to Imad Shaham

TI__Mastermind 20431 points

hi Imad

have the system give you any feedback why it is denied?

i am afraid that i can't approve the GUI to you.

thanks

jesse

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TAS5782M: Inquiries about AC Coupling, Dithering, Mute, and the Programmer