which ic are voltage mode controller

[raju v g]

hi i am doing a project on buck converter
my specfication is 326v input, 200v output,300W power
which voltage mode pwm controller i want to use for this?????????
please help me .....

 

[dick_freebird]

I don't think the controller matters particularly. You're looking
at an isolated high side gate control almost certainly, though
you might find a 500V half-bridge or high side gate driver.
You're not going to direct drive the high side switch with any
commercial PWM I've seen.

UC1525 is the grand-daddy. There're plenty of others I
am sure. Selection probably comes down to features you
have yet to describe.

 

[raju v g]

but uc1525 ic duty cycle max is 50% but i need duty cycle varation up to 100%
is it possiable to use current mode pwm controller for to control voltage

 

[Tahmid]

Hi,
You can take a look at UC3842 and UC3843, which can operate upto 100% duty cycle. But these are current mode controllers, so when you go above 50% duty cycle you must add slope compensation.

Hope this helps.
Tahmid.

 

[Megha Diggavi]

Hai..... Can you tell me how to change the pulse width or duty cycle for UC 3843 ic? I am doing project using this ic but i don't know how to set the duty cycle. Can u help me?