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TPA6112A2 SHUTDOWN and Mute

Other Parts Discussed in Thread: TPA6112A2, TPA6130A2

Hi Team,

The customer has the issues about TPA6112A2. He wants to control the device mute through the SHUTDOWN pin. 
The requirements are as follows:

First,the device must be mute at once when the SHUTDOWN pin is high level.

Second,after 3~5 seconds, the SHUTDOWN pin is  low level and the device should work normally. 

Can the SHUTDOWN pin of TPA6112A2 meet the customer's requirements? If not, please recommend me a suitable IC.

Thanks.

Best Regards,

  • Hi Mickey,

    The first requirement should be covered by TPA6112A2.
    Regarding the second requirement, you mean that you need the device to remain muted for 3-5 seconds after the shutdown pin is back to the low state?
    One additional note, the TPA6112A2 uses a Bypass capacitor to regulate the internal generated mid-rail voltage which needs to be charged and discharged when the device is enabled and disabled. The DirectPath devices (TPA613x) use a charge pump to generate a negative rail voltage, this allows the device to eliminate the Bypass capacitor and also centers the output to 0V which also eliminates the need for output capacitors, but these devices are lower output power.

    Best regards,
    -Ivan Salazar
    Texas Instruments

  • Hi Ivan,
    Thanks for your reply.
    Q1: " SHUTDOWN=0V, IDD=1.5mA~3mA; In SHUTDOWN mode, SHUTDOWN=VDD, IDD=10uA~50uA". I only see this in the data sheet.

    If TPA6112A2 is in SHUTDOWN mode,  is the device muted?
    First,the device must be mute at once when the SHUTDOWN pin is high level. You mean this can be correct, right?

    Q2: Yes. The customer needs the device to remain muted for 3-5 seconds , after the shutdown pin is back to the low state.
    How to to achieve this function? First, the SHUTDOWN pin remains high level for 3-5 seconds, then the pin s back to the low state, right?
    If not ,can you give me a reference circuit?
    Best Regards,

  • Update:
    I see TPA6130A2. TPA6130A2 has the mute function. Can TPA6130A2 meet the customer's requirements?
    The customer's requirements is the device remains muted for 3-5 seconds , after the device works normally.
  • Hi Mickey,

    Regarding Q1, yes, when TPA6112A2 is in shutdown the device is muted. And yes, the statement can be correct, although as I said in my last post, the bypass capacitor needs to be discharged so it will take a few miliseconds for the device to be completely muted after triggering shutdown pin.
    Regarding Q2, you're right, the shutdown pin should remain high for 3-5 sec (the delay time you need) and then go to low state. You may need to add a discharging delay somehow. This is not a very common use of the shutdown feature so unfortunately there is no reference design that solves this requirement.
    TPA6130A2 has mute function, but this device is controlled through I2C, not hardware controlled. Here you may need to delay the mute command.

    Best regards,
    -Ivan Salazar
    Texas Instruments
  • Hi Ivan,
    Thanks for your reply.  I want to know which capacitor is the bypass capacitor what you said.  Is the capacitor of the attachment.?

  • Hi Mickey,

    The bypass capacitor is C(B), the one connected to pin 4 (BYPASS).

    Best regards,
    -Ivan Salazar
    Texas Instruments
  • Hi Ivan,
    Thanks.
    The customer wants the device to be completely muted in a few miliseconds, is TPA6130A2 OK? Or any other IC?

  • Hi Mickey,

    TPA6130A2 is OK, actually it shutdowns immediately. You can see the shutdown response in its datasheet page 26 figure 46.

    Best regards,
    -Ivan Salazar
    Texas Instruments
  • Hi Ivan,
    OK. Thanks.
  • Hi Ivan,
    The customer has another issue. He uses TPA6112A2. He needs the time from muted to unmuted or from unmuted to muted that is in 1s. But the time from muted to unmuted or from unmuted to muted is about 3s in his design. So he thinks the time is very long. Is the time 3s normal? If not, what is the reason and how to solve the issue? If that is normal, please recommend a suitable IC.

    Thanks.
  • Hi Mickey,

    This device does not have a fast start up time, but it should be lower than 3s.
    Actually the start-up time should be close to 1s.
    Could you share more details about the application like schematic and captures? You can e-mail those to ivan.salazar@ti.com

    Best regards,
    -Ivan Salazar
    Texas Instruments