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TPS65185: About external component of VDDH charge pump

Guru 21045 points
Part Number: TPS65185

Hi Team,

 

Our customer would like to know about external component of VDDH charge pump.

 

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[Q1]

We understand that the function of 100nF between VDDH_D and GND is bypass capacitor.

Is my understanding incorrect?

If this capacitor is not connected, is there a possibility that VDDH charge pump(VDDH_D) can't output?

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[Q2]

Our customer would like to change the output of VDDH(22V -> 20V).

Therefore, they are changing the resistor between VDDH_FB and GND(47kohm -> 52.4kohm).

We guess that it don’t have any problem there.

Is my understanding incorrect?

Could you please let us know if you have any concern?


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Regards,

Kanemaru

  • Kanemaru,

    Edit: A 100nF cap on VDDH_D can resolve some conditions that may prevent VDDH from booting properly. For this reason it is recommended to include this capacitor whenever possible. The PMIC can still operate without the 100nF cap, as our EVMs omit this component, but under certain soft-start conditions this capacitor may be necessary to reliably boot.

    Decreasing the charge pump voltage by 1V should not affect operation.

    Best Regards,

    Rick S.

  • Hi Rick-san,

     

    Thank you for the information.

    I understand that they can set VDDH=20V (FB resistor is 52.4kohm).

     

    Regards,

    Kanemaru