Measure ADC of PWM signal

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Measure ADC of PWM signal

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emdev
Contributor III

Hello,

I want to read ADC value of PWM signal.

ADC values are changed.

If read ADC value at lowest value of PWM, it report 0.

But if read ADC value at highest value of PWM, it report Vcc.

I can check MPC5643L_PWM_ADC_concept.pdf and find below image.

emdev_0-1635404275434.png

I want to read ADC at highest value of PWM.

How I can approach it?

Duty cycle of PWM can be changed.

Thanks in advance.

 

 

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igorpadykov
NXP TechSupport
NXP TechSupport

Hi Andrew

 

one can read several samples (the more number, the better accuracy) then compare them in

software and select one with highest value.

 

Best regards
igor

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emdev
Contributor III

Hi igorpadykov,

I used methods which you recommended and it works well.

But I want to check that there are any hardware or chipset level solutions or not?

For example, DMA or automatic method in https://community.nxp.com/t5/MPC5xxx-Knowledge-Base/MPC5643L-PWM-ADC-measurement-concept/ta-p/110265....

If there is no other chipset level methods, I'll use method which you recommended.

Thanks.

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igorpadykov
NXP TechSupport
NXP TechSupport

> I want to check that there are any hardware or chipset level solutions or not?

 

sorry there are no hardware solutions for such task.

 

Best regards
igor

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236 Views
igorpadykov
NXP TechSupport
NXP TechSupport

Hi Andrew

 

one can read several samples (the more number, the better accuracy) then compare them in

software and select one with highest value.

 

Best regards
igor

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