How Step up to step down dc converter

Thread Starter

thedark1811

Joined Dec 20, 2020
40
It possible change the topology of step up converter to step down? like the SX1308, I see in aliexpress some module use the same IC to step down and step up in one board, I cant remember how called the topology used in these board, but it possible do it only change the place of the diode and inductor to do step down topology? I need do 3v to 1.5v.
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Yes it is possible but depending On the chip used, some of them are only for stepping up, some stepping down and some for both. Check Buck regulator for stepping down and Boost for stepping up. You also would have to change how inductor, diodę and Talking capacitor are place so it's probably not so viable for the existing board but yoy can always prototypem something
 

crutschow

Joined Mar 14, 2008
34,452
The are buck-boost converters, such as a CUK type, that can either buck or boost the input voltage as needed to deliver a constant output voltage.
 

Thread Starter

thedark1811

Joined Dec 20, 2020
40
Yes it is possible but depending On the chip used, some of them are only for stepping up, some stepping down and some for both. Check Buck regulator for stepping down and Boost for stepping up. You also would have to change how inductor, diodę and Talking capacitor are place so it's probably not so viable for the existing board but yoy can always prototypem something
I see in aliexpress some use the same ic to do steup and step down but I only need step down,
 

ronsimpson

Joined Oct 7, 2019
3,037
but it possible do it only change the place of the diode and inductor to do step down topology? I need do 3v to 1.5v.
The boost and buck PWM look the same ( diode, inductor, IC, capacitors) but they are not the same and cannot simply be changed. The IC is different, and the parts are almost a mirror image. (simple answer)
 

panic mode

Joined Oct 10, 2011
2,752
I see some ic say Step Up and it is used in step down like the LM2596 LM2577
then you must have better eyes. i have never seen statement that LM2596 can do boost.
the LM2577 is a different story since using SEPIC topology

But it posible only change the diode place?
View attachment 313330
it is not JUST the diode location. note that the SWITCH location is different too. and in some ICs that switch in internal so rewiring is much harder :).
 
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