VDD_PU_CAP of the i.MX6DL

[tomo]

Hello all,

I'm verifying my i.MX6DL custom board that running Android ICS(4.0.4).

I have some questions about the VDD_PU_CAP.

(1) I measured the VDD_PU_CAP. Sometimes, that was drop to approximately 0.2V. Is this correctly?

Operating range of the VDD_PU_CAP is between 1.15V and 1.225V according to the Datasheet (IMX6SDLCEC.pdf : Rev 5).

(2) It looks like overvoltage has occurred when it returns to the normal voltage. Is this cause the software?

(I attached two waveforms.)

[Yuri]

Hello,

  From Table 2-6 (Power and decouple recommendations) of “Hardware Development
Guide for i.MX 6 …”

’Maximum ripple voltage requirements.

Common requirement for ripple noise should be less than

5% Vp-p of supply voltage average value.

Related power rails affected: all VDD_xxx_IN and VDD_xxx_CAP.

< http://cache.freescale.com/files/32bit/doc/user_guide/IMX6DQ6SDLHDG.pdf >

To avoid issues - please follow recommendations of the Table 2-6.

Have a great day,
Yuri

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

[tomo]

Hello yuri,

Thank you for your reply.

This phenomenon has occurred in a SABRE-SD board also, so I can't think it was ripple noise.

Best regards,

tomo

[Yuri]

1.

The SABRE-SD had been designed before the recent  requirements was published 

2.

Additional series resistance may help.

http://www.freescale.com/files/32bit/doc/eng_bulletin/EB814.pdf

Regards,

Yuri.