TAS5805M: Need PVDD to be ON in order to read/write registers

Hi Chad,

As outlined in the datasheet, to start up the device both DVDD and PVDD should be applied to the device. If all that is needed is communication to the digital side of the device, only DVDD is required and PDN must not be asserted as outlined in this E2E post.

Regards,

Ramsey

Hi Ramsey,

Thank you for the reply.  May I confirm with you that "PDN must not be asserted" meaning PDN = LOW?  In your pointer post, it said "PDN = HIGH".

I attached here my circuit for TAS5805M in case if I had any wrong.

So sorry for many questions.  I have another problem that I hope you can point it out for me.  In the prototype, my EE selected TAS5828M device, and I have it work with I2S source output and verify.

But in the real board, the EE switching to use TAS5805M since we need to have heat dissipation differently, and I just found out now the TAS5805M require to have the DSP Coefficient to be loaded using I2C.  I have never need to load any DSP coefficient for TAS5828M.  Can you please point me to any link so I can download DSP Coeff for TAS5805M?

Ramsey,

I experienced the same thing for both TAS5828M and TAS5808M devices, I need both DVDD and PVDD to be ON in order for me to enter the setup for read/write registers.

Case#1: No PVDD Kept Getting Nak from TAS5805M with 4.7KOhms Pull up to DVDD to set address 0x2C

Case#2: Turn On PVDD successfully getting data from Register 0x01 0x02, and 0x03 etc...

TAS5805M in the circuit

Hi, 

as tas5805’s vr_dig also needs pvdd.

if there is no pvdd, the digital power supply cannot work.

you need pvdd to read/write register.

thanks

jesse

Dear Jesse,

Thank you for your confirmation.  Is there any information I can read more about without PVDD the digital power supply can't work?  I reviewed the datasheet but don't see any info related between vr_dig vs. pvdd.

 I have another problem that I hope you can point it out for me.  In the prototype, my EE selected TAS5828M device, and I have it works with I2S source output and verified on the scope.

But in the real board, the EE switching to use TAS5805M since we need to have heat dissipation differently, and I just found out now the TAS5805M require to have the DSP Coefficient to be loaded using I2C.  I have never need to load any DSP coefficient for TAS5828M.  Can you please point me to any link so I can download DSP Coeff for TAS5805M?

Hi Jesse,

I think I understand what is DSP Coeff already.  In my design, we just use amplify as a simple amplification purpose so in our prototype we use TAS5828, and we just playing the sine wave and microcontroller control the analog gain to increase or decrease the amplitude.

In the production one, due to the heat dissipation problem, we switch to TAS5808M for easier heat ventilation but took it for granted thinking of the same TAS58 family so it should be the same and we encounter the issue.

The outstanding issue for me right now is if I use the same sinewave source file that I used for TAS5828M, I always get the Left Right Channel Over Current fault.

There is one thing different in TAS5828M, I has turned on the CBC function in register 0x77, and this is the missing feature in TAS5808M.

Is there any equivalent setting in TAS5805M that match TAS5828M? Or can you think of any reason my either hardware design or setting different that will cause the OverCurrent?

My first work prototype using TAS5828M, we designed as Stereo, and we verify the idea will work with the TAS58

The actual work using TAS5805M we designed as Mono with the though the output can be much stronger