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TAS5719: TAS5719 output PWM duty cycle

Part Number: TAS5719

Hello team,

I have a question about output level.
TAS5719 is open-loop Audio ampliffer, soI belieave  its output lebel to speaker depends on the PVDD, however I think the PWM duty cycle (Modulation Level) was determined.

What is the PWM duty cycle (Modulation Level) of TAS5719 output in the following case.

Input : 0dBFS
DAP : set 0dB at all registers (such as EQ,DRC, Power Limit and etc)


Your help would be so appreciated.

Best Regards,
Akihisa Tamazaki

  • Hi, Tamazaki-san,

    As you mention, the TAS5719 is an open loop amplifier and the output level depends on the power supply voltage. This is a Class-D amplifier where the outputs are PWM signals whose high level will be PVDD. The duty cycle of the PWM outputs is derived from the I²S input, if no I²S input is provided, the duty cycle will be 50%.

     Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer

  • Diego,

    Thank you for oyur reply. I understand TAS5719 is open loop class-D ampkifier.
    I would like confirm PWM signals in the specific case. Please see the pptx file.
    /cfs-file/__key/communityserver-discussions-components-files/6/TAS5719.pptx

    My understanding is correct or not?

    Your advise would be so appreciated.

    Best REgards,
    Akihisa Tamazaki

  • Hi Tamazaki-san,

    Excuse me for cutting in.

    The calculating formula of the output voltage for BTL configuration is as below.

    Output Voltage [Vrms] = 2 * PVDD * (1/(2*SQRT(2)) * ΔDuty Cycle
    ΔDuty Cycle          = Input Signal * Volume Level * Modulation Level

    PVDD              : 12 [V]
    Input Signal      : -20 [dBFS]
    Volume Level      : 0 [dB]
    Modulation Level  : 97.7 [%]

    Output Voltage = 2 * 12 *  (1/(2*SQRT(2)) * 0.1 * 1 * 0.977 = 0.829 [Vrms]

    Best regards,
    Kato

  • Kato-san,

    Thank you. I understand.

    The case I would like to know is
    Input Signal : 0 [dBFS]
    Volume Level : 0 [dB]
    Modulation Level : 97.7 [%] = Modulation Limit

    Maximum Duty Cycle = 1* 1* 97.7[%] =97.7%

    Best Regards,
    Akihisa Tamazaki