DC/DC converter Topology Selection

[berni80]

dc dc converter topologies

Hi,

I need to design a 250W DC/DC converter from 12V to 100V.
I'm here to ask you experience on the topology selection.

Here the main specs:

Vin = 10-18V
Vout = 100V
Pout = 240W
Tambient = 125°C

The load will be highly impulsive (you can immagine a
square pulse load with 25% of duty cycle) and I would like to use
on-the-shelf magnetics.

The targets of this design are small dimensions and robustness.

Thanks!!

 

[Dmitron]

converter topology selection

push-pull is the typical
Pout = 240*4= 960W for 25% time? How quickly will it change?

 

[berni80]

dc-dc converter topologies

In fact the load is a triangle pulse:

It starts form zero and reachs 30A in something like 200us, then
goes rapidly to zero.

The peak output power is 30A * 100V = 3kW...

The main problem is the amount of out capacitor to damp this peak..

Is there any topology specifically designed for impulsive load?
Maybe can a digital control can help?

 

[Dmitron]

converter topology

I guess you need on/off control with comparator. Make some hysteresis and allow the SMPS go at full power or not work at all.
The problem is Feedback speed, wich can be to slow for you application.