Regarding PSoC4S CSX power supply voltage(VDDA and VDDD).

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YuMa_1534086
Level 7
Level 7
Distributor - Macnica (Japan)
500 replies posted 250 sign-ins 10 likes received

Hello Cypress.

I have questions about power supply for PSoC4S CSX component block.

Please confirm and answer below questions.

Q1)

What is PSoC4S CSX component block’s power supply source?

Where does CSX block get power supply from?

Is it VDDA? Or VDDD?

And is the voltage applied directly from power supply source?

Or is the voltage dropped internally?

Is there internal LDO for CSX block?

Q2)

Will VDDA and VDDD affect CSX SNR?

Below is my understanding.

Is below correct?

================================

VDDA does not affect CSX SNR.

But VDDD(or VDDIO) affects CSX SNR.

Because VDDD(or VDDIO) is equal to Vtx.

And CSX SNR becomes higher also if VDDD(Vtx) becomes higher.

================================

Best Regards.

Yutaka Matsubara

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

Hello Matsubara-san,

A1)

IDAC and Vref of CSX are sourced from VDDA and Vtx is sourced from VDDD.

Yes. The voltage is applied directly from power supply source. There is no LDO for CSX block.

A2)

In this case, as you can see, both VDDA and VDDD will be used in CSX block. Therefore, both VDDA and VDDD will affect CSX SNR.

Best Regards,

Ryan Zhao

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