SEPIC Converter Design 12V/2A

[seridj_mse]

hi,

I need a SEPIC converter with the following characteristics

Vin(min) = 11V
Vin(max) = 30V
Vout = 12V
Iout (max) = 2A
f = 100khz - 300khz

found design with LT3759 chip ANALOG DEVICES https://www.analog.com/en/products/lt3759.html#product-overview i dont know if its an high cost design or not and good quality or no too and Analog devices parts are now not used very much in professional design ?

and other think i see some board use regulator like LM2678, LM2596 .... maybe we should ensure that the input voltage is higher than the output but if the input was 12.8v and ouput was 11v its not a problem i can get my 3.3v and 5v from this output ...


Thank you in advance.

 

[BradtheRad]

Does the topology have to be SEPIC? Did you rule out simpler types?

An obvious example is buck-boost which is able to step up or down. However it produces output at opposite polarity to the incoming supply (relative to ground). If your system requires unchanged polarity, then consider cascading a buck then boost converter.

 

[treez]

LT3759 looks ok, but any current mode controller can do a SEPIC.
Perhaps you will pick one which gives you a low dissipation in your source sense resistor.
LTC1871 is another one.
Even UCC28C43.
ti.com do some aswell
and others