Internal Regulator Problems

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Anonymous
Not applicable

Hi,

   

I´m trying to power the CY8C5267-AXI-LP051 from a 5V Supply, but i have the problem, that the internal 1.8V regulator somehow does not regulate to 1.8V, when a voltage higher than 3V is applied to the VDDD-pins of the micro. If I apply 5V the internal regulator output is 3.3V or 3.4V. I looked and looked at the design of my PCB, but I was not able to find the source of the problem.

   

Otherwise, the chip seems to work (somehow) with the higher core voltage (at least for a few seconds), I even managed to program it.

   

I attached two pictures of the PCB to the post, could someone please tell me what I did wrong?

   

Thanks in advance

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Bob_Marlowe
Level 10
Level 10
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Well, I am a system designer, not an electronic engineer. So might it be that you tied VCCA to VCC.

   

Datasheet states (pg 27) do not apply power to the VCCx pins,

   

This is also shown in the schematic on pg 10.

   

 

   

Bob

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Bob_Marlowe
Level 10
Level 10
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Welcome in the forum, Otto 😉

   

I think it would be more helpful when you post the schematic, I assume that your router would be able to create a corresponding board.

   

 

   

Bob

   

PS: And where in Germany are you located, I live near Bremen.

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Anonymous
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Hi Bob,

   

thank you for your answer, I live in southern Germany, near Stuttgart.

   

I attached a PDF of the schematics and the KiCad file to the post.

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Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Well, I am a system designer, not an electronic engineer. So might it be that you tied VCCA to VCC.

   

Datasheet states (pg 27) do not apply power to the VCCx pins,

   

This is also shown in the schematic on pg 10.

   

 

   

Bob

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Anonymous
Not applicable

Many thanks, that was the problem. I did cut the trace to the VCCA pin and now the internal regulator puts out the correct voltage.