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TAS5548 Cannot write to System Control Register

Cornelius Bradter
Prodigy 40 points
Other Parts Discussed in Thread: TAS5342, TAS5548, TAS5508, TAS5518

Hello,

we have plenty of experience with TAS 5518 and TAS 5508 together with TAS5342. Now we are going to change our design to the new TAS 5548. We designed new circuit boards manly based on our old design for SE, Bridged and Parallel Mode of the TAS5342.

Unfortunately, in out test design, after some time of working correctly, we cannot write to the Status Register 1 and 2 (0x03 and 0x04) any more. All other registers seem to work ok. Unfortuneately 0x03 is necessary to end shutdown mode and 0x04 to stop Auto-power-off. Therefore, everything don't work any more.

Ending shutdown mode seems to be the crucial point. Bit D4 cannot be altered. but D7 or D6 work. Playing around with individual channel shutdowns in register 0x27 can make it possible to be able to alter D4 in 0x3 but this does not seem to work all the time. Nevertheless, since the occurence of the described problem, we did not manage to make the design work anymore. Reset and power off do not help.

What is happening? We are completely at a loss. Maybe there are errors in out design - although it worked with TAS5508 without problems. Or are there some properties of the TAS5548 we did not notice?

Thank you for yout help.

Cornelius Bradter

 

 

 

  • 0
    TI__Mastermind 37045 points

    Hi Cornelius,

    It sounds like a strange issue indeed. Does the issue happen on more than 1 device? Have you tried this on the TAS5548 EVM?

    Do you have the device address set properly? The 7-bit address for the TAS5548 is 0011011. When the R/W bit is added as the LSB, the I2C write address is 0x36 and the I2C read address is 0x37.

    reg,

    Paul.

    Applications

    Dallas TX

     

  • 0 in reply to user5276421
    Prodigy 40 points

    Hi Paul,

    thank you for your reply

     

    We have boards for SE, Bridged and Parallel Mode Amplifiers. Up to now we tested the Bridged and Parallel Mode versions, therefore we tested two device - same for both. The SE Version (it is a 16 channel version, therfore there are two TAS5548 on it) has not been tested yet. We hope to find out what's going on with the other version. If we made any errors that eventually destroyed the TAS5548 we don't want to repeat that error on this board. We only have one sample left.

     

    No problems with device adresses. We tested both adresses - 0x34/0x35 and 0x36/0x37 (thanks to TI for the second I2C adress). Please note, we don't have any problems to read or write all of the other registers.

    It is very strange, espacially because both of our boards worked for some time. We don't  have an EVM as we did not expect any problems. We build simular amplifiers with TAS5518/5508 and never had any problems.

    Cornelius Bradter

    PS

    Maybe a strange question... But we really don't have any idea what is going on.

    Is it possible to destroy a TAS5548 by reading/writing some registers? In the datasheet some registers are marked "do not read or write". For evaluation purpose we read all registers - and did not skip those marked "do not read or write".

     

     

     

     

  • 0 in reply to Cornelius Bradter
    TI__Guru**** 189399 points

    Hi, Cornelius,

    You can't damage the device by reading reserved registers. 

    Have you made any progress on this problem?

    -d2