• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 31 subscribers
  • Views 4130 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TAS5711 in PBTL

KANJI SHIBATANI
Mastermind 6205 points
Other Parts Discussed in Thread: TAS5711, TAS5727, TAS5731M

 

Hello

 

My client intends to use TAS5711 as  single filter PBTL  like  attached schematic..

However, there are big POP when PWM had ON ( 0x05= 00) (  wave form attached.

blue and light-blue is each ouput) ,

Following is the register-setting. It seems no problem..

~~~~~~~~~~~~~~~~~client's setting from~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! Factory Trim
X1b 00

! wait 25ms 

! PBTL setting

X20 00 01 77 72

X25 01 00  22  45

X19 3A

! PWM On

X05 00

~~~~~~~~~~~~~~~~~~~~~~to here ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Question 1

The BST cap  in EVM ( C16,C22, C45, C9) are 33nF in EVM, but client use 3.3nF.

What range of should be used for BST cap's value. ( ex at least 10nF...)

Question2

If PBTL pin were High,TAS5711 automatically  set PWM_A = PWM_B, PWM_C=PWM_D ?

If so, I think  0x25=01  00 22 45   (client's setting: PWM1=A=B,PWM3=C=D )  and

also 01 10 32 45 ( data sheet p34  PWM1=B,PWM2=A, PWM4=C,PWM3=D) is both OK  in case

0x19=3A (PWM2 and PWM4= shutdown).

Is it correct?

Question 3

I think TAS5711 work under single filter PBTL,  but you mentioned  TAS5727 is fine  in

another  post. (*)   Would you please let me know the reason?

(*)

http://e2e.ti.com/support/amplifiers/audio_amplifiers/f/6/t/97585.aspx

 

I hope your answer  wtihin2 days

Thank you nad with　my best regards

 

 

  • 0
    TI__Mastermind 34755 points

    Hello Shibatani,

    I will try to post a response later today once I reviewed your post and questions.

  • 0
    TI__Mastermind 34755 points

    Shibatani,

    1. 33nF is definitely recommended, especially in appications with a lot of low frequency audio content (e.g. subwoofers). This ensures there's enough charge in the BST cap to keep the HS FET on for long durations.
    2. Both case will work. Please note in PBTL mode register 0x25 PWM setting for both OUT_B is used for OUTA and OUTB and PWM setting for OUT_D  is used for both OUTC and OUTD. This is muxed internally when PBTL mode is used.
    3. Yes, the d/s says it supports single filter PBTL. TAS5727 is a newer device to TAS5711/3 and has more updated protection schemes, which makes it even more reliable. We would prefer to support the newer devices for new development over the older devices providing that the newer devices meet the customer needs.
  • 0 in reply to Damian Lewis
    Intellectual 255 points

    Damian, 

    In PBTL does BSTA need to be connected to BSTB, and BSTC need to be connected to BSTD? I know this is a requirement for the TAS5731M, but I see no reference to this on the TAS5711? I would assume that the BST pins need to be synchronous for all paralleled output stages.

    Thanks, 

    Adam

  • 0 in reply to Adam Lock
    TI__Mastermind 34755 points

    Hi Adam,

    This isn't a requirement for TAS5711 as for TAS5731M.  This is requirement based on the output power design, which is different for the two devices.