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I have a task of creating a boost DC-DC converter that can convert 3-4 V input into 12-16 V output with 100 W power and high efficiency.

There is nothing similar that I could find on the internet. Could someone give pointers to such designs or ICs?

ocrdu
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Isso
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    (Ouch. Forget diodes.) – greybeard Mar 07 '23 at 17:54
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    Have you tried TI webench? – winny Mar 07 '23 at 18:01
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    You must first define what is the limit between efficient and inefficient. Then search for boost circuits which are above the limit. – Justme Mar 07 '23 at 18:05
  • That's going to have a nice fat current spike on the boost mosfet. – Barleyman Mar 07 '23 at 18:13
  • @winny It used to be really great but the "improved" version dropped ability to tweak the feedback loop to your heart's content. So you now get something, better like it or crack out the vintage process of spending ages on the analysis with octave et al. – Barleyman Mar 07 '23 at 18:15
  • Does Vout need to be regulated ? Does Vout need to be variable ? .If not then there are lots of simple ways. – Autistic Mar 07 '23 at 21:40
  • Yes Vout needs to be regulated and variable from 12 to 16V. Efficiency would be nice to have above 92% – Isso Mar 08 '23 at 08:13
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    If this is a hobby / low-budget thing, maybe look through the vast number of USB power bank chips available, there might be some supporting 1S Lithium input (which would be around the 3-4V range) and they would be able to output 12,15,20V for USB-C PD. – Manawyrm Mar 08 '23 at 08:57

2 Answers2

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I have used one of my ready-made free templates with a 200-kHz interleaved boost converter operated in CM and I can deliver 100 W from a 3-V source. The inductor current peaks to 19 A and the rms current in the output capacitor is 8.3 A:

enter image description here

It's obviously not a design but rather a quick sim to show that, on the computer, you could deliver 100 W from the 3-V cell: there is obviously more to explore on the subject : )

Verbal Kint
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An update: TI Workbench didn't help as it couldn't find anything suiting my parameters. Also I'm not proficient enough to use the information in the answer by Verbal Kint.

However I was able to partially solve this task by using SC8802 DC-DC converter chip, which also has a nice feature of working bi-directionally, i.e. in addition to boosting the battery voltage it also can charge the battery from an external DC source.

I used SC8802 along with 4 pcs of BSC015NE2LS5IATMA1 147A MOSFETS, as well as 7443642200 30A inductor. I was able to get 60W power out of a single Li-Ion cell. The current draw from the cell was almost 20A and the efficiency was about 86-89%.

I guess I can tune this circuit to achieve higher power. However it looks to me that it may be quite hard to achieve higher efficiency, if at all possible.

Isso
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