[SOLVED] DCD/DC step-up (boost) converter with high output current

[howlad]

Hey all,

I am currently trying to design a step-up converter for an autonomious fuel cell system. It has to suffice the following demands:

Vin, min = 4 V
Vin, max = 8 V

Vout = 12 V
Iout = min 2 A

Since a fuel cell has its peak current at lowest voltage, the converter has to be able to deliver 12 V / 2 A at 4 V input voltage (and approx. 8 A). The fuel cell stack is rated at 50 W but it's very old, the realistic maximum power is about 30 -35 W. The output power (and thus the output current) should be as high as possible. Assuming an efficiency of about 80%, the output current should be around 2 amps...
I've already designed a working converter as a first step (using the Maxim MAX 1771 -> ) but that one has a maximum ouput current of 0.5 A.

Does anyone know a converter I could use?

Many thanks in advance,
Steve

 

[Genovator]

LT3579 is little close to your requirements- 5V in, 12V 1.7A out. I can only guess that if you could provide full 8V as Vin, the output current could go to near 2 A. See if you can go with it....

 

[howlad]

Thanks for your answer (and sorry for my late reply).
I figured the TI LM3488 will work best for me (with external switch)

Cheers,
Steffen