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USB superspeed peripherals Forum Discussions

ChDU_4667611
Level 1
Level 1

Hello,

We have some voltage spikes each 330 ms on AVDD. If we do not considering those spikes, we have a ripple less than 20 mV, in according to the AVDD CYUSB306X datasheet specification.

The question are, can we neglect those voltage spikes that appears each 330 ms while we have a ripple less than 20 mV?

If we can neglect this, what impact can cause those voltage spikes?

And can we replace the ferrite by a resistor for filtering those spikes correctly ?

Thanks for your answer.

Capture.PNG

Below the schematic:

torex1.png

torrex2.png

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1 Solution
Hemanth
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First like given First question asked 750 replies posted

Hi,

- If the spike is less than 20mV it should not be a problem.

- Try to increase decoupling capacitance on AVDD and check if the spike reduces.

- Is CVDDQ power shared with any other power domain?

Regards,

Hemanth

Hemanth

View solution in original post

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5 Replies
Hemanth
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First like given First question asked 750 replies posted

Hi,

Wish among the channels measures AVDD? (and what are the other channels?)

Regards,

Hemanth

Hemanth
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Hi,

It's the yellow channel that measure the AVDD signal and the red channel measure the output of the DC/DC P1V2 convertor.

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Hemanth
Moderator
Moderator
Moderator
First like given First question asked 750 replies posted

Hi,

- If the spike is less than 20mV it should not be a problem.

- Try to increase decoupling capacitance on AVDD and check if the spike reduces.

- Is CVDDQ power shared with any other power domain?

Regards,

Hemanth

Hemanth
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Hi,

Thanks for your answer.

The Spike is over 20mV because we measure 23mV.

CVDDQ is not shared with other power domain.

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Hemanth
Moderator
Moderator
Moderator
First like given First question asked 750 replies posted

Okay. Then please try to add more capacitance to that pin and see if the spike voltage reduces.

Regards,

Hemanth

Hemanth
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