TAS5754M/56M Time for Auto Mute and Auto Unmute

Hi Kato,

I will study on this question and let you know once I find the answer.

Amdy

Hi Andy-san,

Thank you for your quick response.

I am looking forward to hearing from you soon.

Best regards,
Kato

Hi Kato,

The TAS5754M/56M should be auto unmuted as long as the continuous zero samples are no longer present. The auto mute time settings are for auto mute control only.

Andy

Hi Andy-san,

Thank you for your information.
I have an additional question.
It seems that the beginning of the sound is lost since TAS5754M/56M does not return from the auto mute mode immediately if writing 0x00 to P1-R6(enabling analog mute).
Do you have any methods to avoid this issue except disabling the auto mute mode ?

Best regards,
Kato

Hi Kato,

Let me check with an EVM.

Andy

Hi Kato,

I find there is a small (about 10.8ms) between DIN being non zero and PWM being on. Is that the same thing you were talking about?  

I guess it is the time delay for the device to complete the transition from the muted state to the unmuted state.  I will try to confirm that.

Andy

Hi Andy-san,

Thank you for evaluating the evm.

Your understanding is correct.
I have got the similar measurement result when unmuting by using P0-R3 register on TAS5754M evm.
As you said, I also guess that this operating is depended on the hardware topology of TAS5754M/56M.
So, do you have any methods to avoid this issue except disabling the auto mute mode ?

<Condition>
- Fybridflow4
- Fs : 48kHz
- Input Audio Source : 100Hz Sine Wave
- PVDD = 12.5V
- P0-R63 : 0xBB(4 x Fs, 0.5dB)
- 6Ω Speaker
- AC Coupling for OUT+/OUT-(after the post filter)

Best regards,
Kato

Hi Kato,

The delay is mostly likely the power-up time for the internal Class-D amplifier.  I don't think I can offer you any approach to getting rid of this delay if the analog muted is enabled by setting the P1-R6 to 0. However, if the analog muted is disabled, then the delay is almost negligible (See the scope shot below).

Andy

Hi Andy-san,

Thank you for your quick response.

I have also evaluated the analog mute function when unmuting by using P1-R6 register on TAS5754M evm.
So, could you please give me your advice since the same result have not been reproduced as below ?

<Condition>
- Fybridflow4
- Fs : 48kHz
- Input Audio Source : 100Hz Sine Wave
- PVDD = 12.5V
- P0-R63 : 0xBB(4 x Fs, 0.5dB)
- 6Ω Speaker
- P1-R6 : Analog Mute "ON" or "OFF"
- Default Settings except P0-R63 and P1-R6

Best regards,
Kato

Hi Kato,

Have you tried the HF5 with a 192kHz input?   Below is the xml file that I have used for that scope shot above.

TAS5756M_HF5_PSIA_192K.xml

Just in case your AP cannot support 192kHz, try this HF3 file below. I can see the same result as I showed to you. 

TAS5756M_HF3_PSIA_48K.xml

Andy

Hi Andy-san,

Thank you for evaluating the evm.

We sometimes use AP on your local office since we don't have it.
Therefore, I have evaluated the auto mute function with hybridflow4 by using I2S USB audio streaming from PC.
Could you please confirm that function with hybridflow4 as well since I cannot do that right away ?

Best regards,
Kato

Hi Kato,

OK. I will double check.

Andy

Hi Andy-san,

Thank you for your continuous support.

I am looking forward to hearing from you.

Best regards,
Kato

Hi Andy-san,

Thank you for bringing it to my attention.
I understood.
So, I plan to evaluate a TAS5754M evm by using AP on your local office this Friday.

Best regards,
Kato

Hi Andy-san

I have an additional question which I got from our customer.
I believe that the digital volume is updated based on R0-R64 if muting and unmuting TAS5754M/56M via /SPK_MUTE pin or P0-R3.
However, as a result of the evaluation it seems that this transition time from the mute status(< -103dB) to the target volume(e.g. -10dB) is very short.
Could you give me that reason about it ?

Best regards,
Kato

Hi Kato,

Could you upload a scope shot so that I can be certain about the transition time you were referring to?

Andy

Hi Andy-san

I have evalutated TAS5754M EVM and got some scope shots as below.

e.g.)
Target Volume              = 0dB
Mute Volume                = -103dB
Volume Ramp-up Step        = 0.5dB
Frequency of Volume Update = 4/Fs[s]
Fs                         = 48kHz

Transition Time[s] = (Target Volume - Mute Volume) / Volume Ramp-up Step * Frequency of Volume Update

Therefore,

Transition Time = 17.17ms

However, as a result of the evaluation it seems that this transition time is very short.
Could you please give me your advice about it since I would like to estimate the transition time if returning from the mute mode ?
Please point out if I have any misunderstanding.
I will also evaluate it by using AP on your local office tomorrow.

<Condition>
- Fybridflow4
- Fs : 48kHz
- Audio I/O : USB
- Input Audio Source : 10kHz Sine Wave
- PVDD = 12.5V
- P0-R63 : 0xBB(4 x Fs, 0.5dB) or 0x00(1 x Fs, 4dB)
- 6Ω Speaker
- P1-R6 : 0x01(Disable Analog Mute)
Note : Default Settings except P0-R63 and P1-R6

Best regards,
Kato

Hi Kato,

I will capture some scope shots and measure transition time as you did.

Andy

Hi Andy-san,

Thank you for your continuous support.
I will evaluate the mute/unmute function at 192kHz processing flow by using AP on your local office today.

Best regards,
Kato

Hi Andy-san,

Thank you for your continuous support.

Could you please check since I sent our evaluation result to your email ?
So, I have some questions as below.

Q1. Return from I2S Halting
Can we set the digital volume ramp-up time if returning from I2S halting ?

Q2. Returen form Auto Unmuting
Why isn't the digital volume ramped up based on P0-R63 if returning from the auto mute ?

Q3. Disable Auto Mute
Is the operating without the analog mute is same with the operating without auto mute ?

Best regards,
Kato

Hi Kato,

I'm looking at the your materials you sent to me now and I will give you my feedback once I figure out the answers.

Andy

Hi Kato,

Q2. Returen form Auto Unmuting
Why isn't the digital volume ramped up based on P0-R63 if returning from the auto mute ?
Andy : If you disable the auto mute function, TAS5756 will not be auto muted even when the SDIN remains zero for a certain period. Therefore, the SDIN becomes non-zero gain, there is no need for a volume ramp-up.

Hi Kato,

Which slides should I look into for Q2 and Q3? I'm bit confused.

Andy

Hi Andy-san,

Thank you for your continuous support.

Could you please give me your advice as below ?

Q2. Returen form Auto Unmuting
My question means that "why isn't the digital volume ramped up based on P0-R63 if returning from the auto mute on the following condition ?" .

<Configuration : Enable Auto Mute>
- Return from SDIN Halting(MCLK, SCLK and LRCK/FS are active.)
- P0-R63 : BBh(4 x Fs, 0.5dB)
- P0-R65 : 07h(Enable Auto Mute)
- P1-R6 : 00h(Enable Analog Mute)

Q3. Disable Auto Mute
I would like to know whether there is the operating difference between the configuration 1 and configuration 2 as below.

<Configuration 1 : Disable Auto Mute>
- Return from SDIN Halting(MCLK, SCLK and LRCK/FS are active.)
- P0-R63 : BBh(4 x Fs, 0.5dB)
- P0-R65 : 04h(Disable Auto Mute)
- P1-R6 : 00h(Enable Analog Mute)

<Configuration 2 : Disable Analog Mute>
- Return from SDIN Halting(MCLK, SCLK and LRCK/FS are active.)
- P0-R63 : BBh(4 x Fs, 0.5dB)
- P0-R65 : 07h(Enable Auto Mute)
- P1-R6 : 01h(Disable Analog Mute)

Best regards,
Kato

2Hi Andy-san,

Thank you for your comments.
I understood about Q3.
So, I am looking forward to getting your comments about Q1 and Q2 from you.

Best regards,
Kato

Hi Andy-san,

Thank you for your comments.
As a result of having compared 192kHz@Fs with 44.1kHz@Fs, is my understanding correct that the transition time depends on Fs regarding Q1 and Q2 ?

Best regards,
Kato

Hi Andy-san,

Thank you for your information.
I understood.
By the way, we are looking forward to getting the root cause and the workaround on the pop noise issue since we have not got them yet.

Best regards,
Kato