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TPS82085: what is load threshold for entering power save mode

Part Number: TPS82085

Hi Team,

Customer doesn't want device enter power save mode because it will create extra noise, some device is sensitive to the noise.

So customer is asking how not-to-enter power save mode at light load.

Currently they put dummy load, but customer wants to know how to design for the dummy load value.

Use case condition:

Vin = 3.3V

Vout = 1.2V

Iload typ = in middle of design, unknown.

Thanks!

Andrew

  • Hi Andrew,

    Thanks for your question.

    There is no clear threshold between PSM/PWM operation.

    We can try to test it out in the lab with your VIN/VOUT, but then the precise value could change according working conditions, for example temperature, component tolerances...

    In order to reach a 'safe' solution they would have to oversize the dummy load current, destroying completely the converter efficiency.

    Could I propose you a device that can be settle to work in forced PWM? For example the new TPSM8281x.

    If you set the module to forced PWM, you would obtain the wanted result without introducing any dummy load.

    Another solution, if applicable, could be to put an LDO in cascade to the module. The LDO should filter the converter output, reducing consistently the noise.

    Please ask again if you need further support.

    Thanks,

    Stefano

    All information in this correspondence and in any related correspondence is provided “as is” and “with all faults”, and is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • Hi Stefano,

    Thank you for the quick feedback!!

    Andrew

  • Hi Andrew,

    I will close this thread now and answer to you by email.

    Feel free to reply below if you need further support.

    Thanks,

    Stefano

    All information in this correspondence and in any related correspondence is provided “as is” and “with all faults”, and is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).