Buck-boost dc/dc converter with a wide range

[Velectro]

Hi everyone,

I want to charge two sla battery with a solar panel, so I need a dc/dc convert with this range:

Vin = 9 - 24 V
Vout = 12 - 15 V

I load max = 5A

I looked for many time but I did'nt finde anythingh, any know some dc/dc converter that I can use?

 

[justDIY]

since your input and output ranges overlap, you're going to have to use one of two technologies

flyback aka buck-boost

-or-

SEPIC (single-ended primary inductance converter)

check out the usual suspects, I've seen chips that handle the numbers you request ... Maxim, National, Linear, ON, etc

but, I don't think you nessecarly need a buck-boost circuit, your solar cell's open circuit voltage is going to be totally different than the under load voltage. if you have an array capable of outputing 5amps, then you just need a charge controller, which regulates the charging current to maintain optimal output from the cells... voltage takes a back seat to current in this situation (in terms of importance).

 

[Velectro]

Firstly I want thank you for your reply.
Actually I'm considering an LTC3780 (4 switch Buck - Boost Controller) but I'd like a solution less complicate.
I'm using a monocrystal sola panel (100w) that in good light condition output 15 V and 3 A as a current generetor he move the Voltage for mantain constant current.
In the battery constant Voltage charge method we need to mantain a costant voltage, so we need a DC/DC converter with this V,I range.
So have you any suggest?

Tanks