High duty cycle boost converter

[eem2am]

hello,

i need a high duty cycle boost converter ic (pwm controller)

i need to boost from 2v to 25v and with 3 Watts output power

does any body know of such a high duty cycle IC?

 

[Tahmid]

Hi,
Take a look at this:

Hope it helps.
Tahmid.

Added after 4 minutes:

Take a look at the datasheet of MAX669:
http://www.datasheetcatalog.org/datasheets/400/443791_DS.pdf

 

[powerpratik]

3W o/p Power = 25 o/p voltage * unknown o/p current.
So o/p current is too low.
for these you don't necessary high duty cycle.

calculate simply boost converters capacitor and inductor for the same.

what about your load? is it 3w?

 

[svhb]

Powerpatrik, I don't see your point.

I think if ee2am talks about 3W output power, he has a reason for that. 3W/25V = 120mAmps.

 

[eem2am]

thankyou,

but we really need something with 99% duty cycle and it doesnt exist.

does any reader know of a push pull ic for this job...with on-chip fets?

 

[svhb]

I only see 92% duty cycle.

If this is still a problem, you can try a two step system. 2-->7 and 7-->25 (two times around 72% duty cycle)