Looking For The Right DC\DC Step Up Converter

Dominic Luciano

Other Parts Discussed in Thread: TPS61020, TPS61070, TPS61222

Hi there!

I need a DC\DC Step Up unit for my project. I found one from Linear Technology that works brilliantly (LTC3427), but since I have all my other chips coming from TI, I'm looking for one they have that will operate the same.

Here's the LTC3427 datasheet

Basically I need to take somewhere between 1V-2.2V and turn it into a steady, solid 5V @ roughly 100mA.

I was looking at this one, but I don't think it's going to work. I don't need anything fancy as it's an all analog project (no digital anything).

Any help would be greatly appreciated!

over 10 years ago

0 Jasper Li over 10 years ago

TI__Mastermind 46905 points

what is minimum input voltage, the LTC3427 can only support minimum 1.8V Vin.

you can have a loop at TPS61070 or TPS61020, depending on your output power and minimum Vin.

Jasper Li

0 Dominic Luciano over 10 years ago in reply to Jasper Li

Prodigy 60 points

It's 1.8-2.2V, but I'm just putting a broader range because the TI step ups seem to have a broader range. As for current, all I know off hand is roughly 100mA last I checked.

I just need 5V @ 100mA output

0 Dominic Luciano over 10 years ago in reply to Jasper Li

Prodigy 60 points

It looks like the 61222 can do ~110mA max at 2.2V, and the 61070/1 can do about 175mA max at 2.2V.

So this leads me to my next question, which is the math. It's never been my strong suit which is evident by the fact I'm getting different values every time I run the equations, so could someone lend me a few minutes to help me out with it?

0 Jasper Li over 10 years ago in reply to Dominic Luciano

TI__Mastermind 46905 points

i don't think TPS61222 can support 5V/110mA, but its no problem for TPS61070 to support 100mA/5V at 2.2V input. you should consider the worst case.

here is link about how to calculate the max output current of a boost converter.

http://www.ti.com/lit/an/slva372c/slva372c.pdf

jasper li

Power management

Power management forum

Looking For The Right DC\DC Step Up Converter