KL720 power pin decouping and filter

Son Nguyen · April 24

Dear Sir,

I have some questions regarding to power domain and power decoupling, filtering:

1/ If I do not use the USB 2.0 interface, Could I not supply power and decoupling capacitors for USB 2.0 power pins? Same for interface in bank 3?

2/ Using the Ferrit bead to isolate between power rails is needed, right? But Figure 3 - Power topology: KL720 bypass capacitors in the KL720 HW design guide v0.2, do not show the ferrite bead between power rails. Could you say me what is right/recommended?

In demo board design

Figure 3 - Power topology: KL720 bypass capacitors in the KL720 HW design guide v0.2

eddie.kuo · April 25

Hi,

If you do not intend to utilize the USB 2.0 functionality, you can disregard the highlighted area in red in the attached image. However, please do not overlook "VCC33A_USB2" and "VCC18A_USB2", and Bank 3 section as well.

We apologize for any inconvenience caused. The use of the Bead component is necessary in the circuit design. We will amend the documentation accordingly. Thank you for bringing this to our attention.

Son Nguyen · April 25

https://www.kneron.com/forum/discussion/comment/1720#Comment_1720

Thanks Eddie Kuo.

" We apologize for any inconvenience caused. The use of the Bead component is necessary in the circuit design. We will amend the documentation accordingly. Thank you for bringing this to our attention. "

==> When the document is done, could you share it with me? We need to check and update to KL720 power decoupling and filtering in our design. We are using the KL720 269-Ball package.

eddie.kuo · April 26

Hi,

The document update request is in progress. Please keep an eye on Kneron Developers. The package you are using is BGA269, and you can follow the design method of the Demo board.

Son Nguyen · April 26

https://www.kneron.com/forum/discussion/comment/1724#Comment_1724

Thanks Eddie.

I am copying the power decoupling and filtering section the Demo board rev 03 for our design. Is this the latest version of demo board?

Besides, I could not find information of ferrite bead ( P/N: BS1005UA 102A03 ). Could you provide me recommended parameters of Ferrite bead or any recommended ferrite bead P/N that could be found on market?