5v steup-up converter?

[blapcb]

On my board most of the components are 3.3v and there is one (important one) that is 5v.
Presently I am using a power section that has a 5v switcher and then a 3.3v LDO.
Now I need to add a 3.8v section (to accommodate a GSM module). But I don't want to use two switchers.
So, what I am thinking is that I could have a 3.8v switcher and then a 3.3v LDO (basically same as now). And then, use a 5v step-up converter (up from 3.8v).

My question is, since I have never used one before, is this a good idea? Sorry I know it sounds like a lame question but, is there anything in particular to know/consider about using step-up converters and is this approach OK?

Thanks

 

[FvM]

I think, the decison is depends mainly on efficiency and possibly interference/power quality criteria. I guess, that the GSM module with it's about 2 A peak current requirement will mainly determine the power supply scheme. Step-up converters aren't basically more probmematic than step-down, you can refer to a large offer of existing chips. In some cases (low current demand), it's appropriate to connect a simple voltage doubling rectifier to another switcher and add a LDO to generate the additional supply rail.

 

[goldsmith]

Hello Dear blapcb
How much current do you need? in my idea , you can design a simple multi winding fly back converter , to obtain all of the voltages that you need straightly . but it depends on your maximum current . ( it's efficiency will be good.)
Best Wishes
Goldsmith