About 22 μF bulk capacitor on MCIMX6Q-SDP.

[keitanagashima]

Dear All,

Hello.

Refer to Table 2-6. Power and decouple recommendations in IMX6DQ6SDLHDG (Rev.1).

Only one 22 μF bulk capacitor should be connected to each of these on-chip LDO regulator outputs:

- VDD_ARM_CAP

- VDDARM23_CAP

- VDD_SOC_CAP

- VDD_PU_CAP

I'd like to know why does freescale recommend the 22 μF bulk capacitor.

We'd like to use the 10 μF bulk capacitor.

What problem is there, when the capacitor smaller than the recommendation size?

Best Regards,

Keita

[igorpadykov]

Hi Keita

this value is choosen due to ripple requirements given in

Table 2-6. Power and decouple recommendations

5% Vp-p for Maximum ripple voltage requirements.

Yes, one can use smaller size capacitor.

Best regards

igor

-----------------------------------------------------------------------------------------------------------------------

Note: If this post answers your question, please click the Correct Answer button. Thank you!

-----------------------------------------------------------------------------------------------------------------------

[keitanagashima]

Dear Igor,

Hello.

Thank you for your prompt reply.

Let me clarify my understanding.

When we select the smaller capacity from 22uF (recommendation), is it OK the we keep a 5% Vp-p for Maximum ripple voltage requirements?

By choosing the small capacitor connected with VDD_xx_CAP, is there another problem except the ripple noise?

Best Regards,

Keita

[igorpadykov]

Hi Keita

this is customer responsibility to provide

5% Vp-p for Maximum ripple voltage requirements with

smaller capacitor value .

22uF value is verified and provides that.

Best regards

igor

[keitanagashima]

Hi Igor,

Thank you for your reply.

OK. Thanks!

Best Regards,

Keita