• Resolved

TPS63070EVM-693: Output Ripple Voltage

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Replies: 16

Views: 373

Part Number: TPS63070EVM-693

Hi,

Could you please provide me the screenshot of the output ripple voltage with TPS63070EVM-693 under the following conditions ?

Test Conditions
- VIN  = 4.0V
- VOUT = 5.0V
- Output Load = 1A
- Switching Mode = Forced PWM mode

Best regards,
Kato

  • In reply to Sadanori Kato:

    Hi Kato-san:

    I didn't add any more caps for EVM.

    And may you share the details requirements with us?

    Best Regards

    Minqiu

  • In reply to Minqiu Xie:

    Hi Minqiu-san,

    The output ripple voltage(620.89mVpp) is higher if disabling the low pass filter with an oscilloscope.
    This symptom is consistent with the results measured by our customer with TPS63070EVM-693.
    So, could you please tell me the recommended workaround to reduce this ripple noise ?

    Best regards,
    Kato

  • In reply to Sadanori Kato:

    Hi Kato:

    I'll recommed to add a ferrite bead. Like 100ohm/100MHz. As it depends on the system design and requirement. So I'am not sure the spec is the most suitable one.

    A π filter could reduce the noise as well, but it may decrease the efficiency. 

    Besides, you could also replace the cap close to Vout pin with smaller size and less parasitic parameters, and add another 10uF with other caps.

    Best Regards

    Minqiu

  • In reply to Minqiu Xie:

    Hi Minqiu-san,

    Thank you for the information.

    I will inform your comments to our customers.

    By the way, the output ripple voltage seems to be large, so what is the reason ?

    Best regards,
    Kato

  • In reply to Sadanori Kato:

    Hi Kato-san:

    The capacitance has parasitic parameter and the impedance will be larger for the high frequency. (More like an inductance in if the frequency is extra high.)

    You could advice customer to add small size caps with less parasitic parameter to reduce the noise.

    Best Regards

    Minqiu

  • In reply to Minqiu Xie:

    Hi Minqiu-san,

    Thank you for your quick response.

    I will suggest our customer to add small size capacitors such as 1nF and 0.1uF.

    Best regards,
    Kato