Boost converter 2V to 28V

[eem2am]

Hello,

We need to do a boost converter for 2V to 28V.

Output power is 2.6W Maximum.

The load is a buck converter powering a LED Lamp (voltage 24V) , so there is no need for fast transient response.

Is this step-up ratio possible?

 

[keith1200rs]

Any stepup ratio is possible. You could try putting the requirements in to the tools on National Semiconductor's site, although I often find it comes up with 'no solution' for my applications and I have to do the design by hand.

For low input voltage, high output, try the Linear Technology LT1308, I think it is. I will check tomorrow when I am at my computer.

Keith

 

[FvM]

Any stepup ratio is possible.

Possible yes, reasonable no. The switched power (and also the expectable switching losses) of a single inductor buck or
boost converter are a function of Imax * Vmax, increasing with step-up (respectively step-down) ratio. If the power is
low or efficiency isn't an issue, factors of 10 to 20, or even more may be acceptable, but a transformer gives usually
better performance.

 

[keith1200rs]

2V to 28V is only 14x. I have done 24x with the LT1308 and more than 50x with other circuits. I cannot remember the efficiency, but with the 24x LT1308 circuit I know it was reasonable because it was a battery powered product where I had to meet a specification.

Keith

 

[Dmitron]

look for zxsc300 IC