I want to design a 75V input with 12V,20A output close loop buck converter, below is the reference diagram for the design from Texas instruments , what modulator and error amplifiers I should be using?

Moderator's note: Predecessor thread: https://forum.allaboutcircuits.com/threads/75v-12v-buck-converter-with-feedback.194936/#post-1835527

 

what modulator and error amplifiers I should be using?

You can use LTC6992-1 chip as PWM modulator:
https://www.analog.com/media/en/tec...ata-sheets/ltc6992-1-6992-2-6992-3-6992-4.pdf

ADDED:

search for Webbemuch power designer

https://webench.ti.com/power-designer/

 

Why don’t you go to TI’s website and see what their power supply designer suggests?
I’d send a link but TI’s website and my iPad seem to have a disagreement with TIs website thinking the iPad is running Internet Explorer 11.
search for Webbench power designer.

 

You can use LTC6992-1 chip as PWM modulator:
https://www.analog.com/media/en/tec...ata-sheets/ltc6992-1-6992-2-6992-3-6992-4.pdf
View attachment 298589
ADDED:

https://webench.ti.com/power-designer/
View attachment 298590

Thanks that helped alot, is the webench design are reliable to imply?

 

Why don’t you go to TI’s website and see what their power supply designer suggests?
I’d send a link but TI’s website and my iPad seem to have a disagreement with TIs website thinking the iPad is running Internet Explorer 11.
search for Webbench power designer.

Go into the safari>advanced>experimental features (you can turn as many on/off that you want, in theory turning them all off/on should solve the issue) I’m not positive which setting it is that could be doing this for you as the list changes after any update. I had the same problem with websites not being recognized, and 4g videos not being “supported” I hope that it helps.

 

Thanks that helped alot, is the webench design are reliable to imply?

I can not say about webench anything, because I did not use it.
Pay attention to LTC3703 chip:
https://www.analog.com/media/en/technical-documentation/data-sheets/3703fc.pdf

Iout depends on FETs and inductor parameters.
You can play with simulation file (attached).