LM5170EVM-BIDIR: LM5170-EVM-BIDIR-Voltage at Vea

Muhammad Salman

Part Number: LM5170EVM-BIDIR

Hello TI team

I m using the LM5170-EVM BIDIR, I want to connect externally the isolated ampliier to the board, I want to take the input from the duty cycle of the inner loop control. I want to know about the voltage value at Vea at COMP pin, what it would be so that I can design an isolator accordingly.

Thanks

over 1 year ago

0 Harry Hofner over 1 year ago

TI__Genius 16245 points

Hello Muhammad,

Thanks for reaching out to us via e2e.

At the moment our team is very busy. May I ask you for some time, please.

We will get back to you at the beginning of next week.

Thanks and regards,

Harry

0 Feng Ji over 1 year ago

TI__Genius 13655 points

Hi Muhammad,

Please describe your question clearly. What does "isolator" mean? Do you want an isolated PWM signals or isolated vlotage?

Best Regards

Feng Ji

0 Muhammad Salman over 1 year ago in reply to Feng Ji

Intellectual 260 points

Hi Feng Ji

I want an isolated PWM signal (duty cycle signal), I want to connect an isolator amplier to the board which will give isolation between input and output. I want to take a signal which is at Vea and will give that signal to the isolator. The purpose is to avoid noises and I want to connect that to the microcontroller and an observer model.

0 Harry Hofner over 1 year ago in reply to Muhammad Salman

TI__Genius 16245 points

Hello Muhammad,

Feng is out on travel today. Please allow for the beginning of next week to get an answer.

Thanks a lot,
Harry

0 Feng Ji over 1 year ago in reply to Muhammad Salman

TI__Genius 13655 points

Hi Muhammad,

You may use an isolation amplifier to achieve this. What is your question?

Best Regards

Feng Ji

0 Muhammad Salman over 1 year ago in reply to Feng Ji

Intellectual 260 points

Hi Feng Ji

My question is that what is the possibe voltage would be at the point of Vea (COMP) just before PWM comparator?

Thanks

0 Feng Ji over 1 year ago in reply to Muhammad Salman

TI__Genius 13655 points

Hi Muhammad,

COMP1 and COMP2 would be the point.

Best Regards

Feng Ji

0 Muhammad Salman over 1 year ago in reply to Feng Ji

Intellectual 260 points

Hi Feng Ji

Yes, I know but what would be the possible voltage measurements range at this point?

Thanks

0 Feng Ji over 1 year ago in reply to Muhammad Salman

TI__Genius 13655 points

Hi Muhammad,

For CCM buck application, the steady state comp pin voltage should be Kff*Vin*Vo/Vin+1V.

KFF is the ramp generator coefficient. When the RAMP signal is generated per Equation 14 , KFF = 0.104.

Best Regards

Feng Ji

0 Muhammad Salman over 1 year ago in reply to Feng Ji

Intellectual 260 points

Hi Feng Ji

Thanks for the clarifiaction, and for the boost application?

0 Feng Ji over 1 year ago in reply to Muhammad Salman

TI__Genius 13655 points

Hi Muhammad,

For CCM boost application, the steady state comp pin voltage should be Kff*VHV*(1 - VLV / VHV)+1V.

KFF is the ramp generator coefficient. When the RAMP signal is generated per Equation 14 , KFF = 0.104.

Best Regards

Feng Ji

0 Harry Hofner over 1 year ago in reply to Feng Ji

TI__Genius 16245 points

Hello Muhammad,

I have not seen an update from you for the last 15 days, so I assume the questions are answered and the issue is solved.
I close this thread now. If there is still something open, please reply and the thread will get opened again.
If you have any other question or of the thread has been locked, please open a new one.

Clicking the Resolved Button also helps us to maintain this forum.

Best regards,
Harry

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LM5170EVM-BIDIR: LM5170-EVM-BIDIR-Voltage at Vea