Psoc 4 Suuply in 5V and SD card supply with 3.3V

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vibac_1329666
Level 2
Level 2

Hi everyone,

I've got some trouble with my PCB card. I have Three PSOC 4 CY8CKIT-142 supply with 5V and Three SD card socket supply by a different 3.3V.

The three PSOC 4 have the same code and project. But there is a little problemn, one of the Card works perfectly fine, but the two others don't work.

Does the supply of the PSOC 4 can be a probleme to discuss with SPI for the SD Card, did i need to supply the PSOC 4 in 3.3 V ?

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1 Solution
RyanZhao
Moderator
Moderator
Moderator
250 sign-ins First question asked 750 replies posted

Hi Vivien,

Yes. I think it does. Different supply domain will cause unrecognized voltage level on SPI lines. One card works and other two doen't work, could be caused by that.

If it still can't work after changing supply level, suggest to monitor SPI signals to check what problem it could be.

Thanks,

Ryan

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3 Replies
RyanZhao
Moderator
Moderator
Moderator
250 sign-ins First question asked 750 replies posted

Hi Vivien,

Yes. I think it does. Different supply domain will cause unrecognized voltage level on SPI lines. One card works and other two doen't work, could be caused by that.

If it still can't work after changing supply level, suggest to monitor SPI signals to check what problem it could be.

Thanks,

Ryan

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Hi thanks for your answer but does the CYBC4247LQI-BL483 Kit just transform the 5V tension into a 3.3V level itself ?

Or do i need necessarly an extern action to do that because when i'm in PSOC Creator "pin" section, i see that the kit have potentially 3.3V VDDR ( Can i supply the VDDR in 3.3V to solve my problem )?

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Hi Vivien,

Sorry for that the device is not able to transform the 5V into a 3.3V level itself. If 3.3V VDDR is required, there must be an external 3.3V supply.

Thanks,

Ryan

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