LM5176: Parallel operation

Mark Pieper

Part Number: LM5176

I would like to parallel two converter designs. Is this recommended? Can you answer the following questions?

1. The 1.6V offset on the EA isn't toleranced. What is the expected variation in this offset? This is one of the components in the calculation of parallel current share error.

2. I would set one transconductance EA as the master and bias the other one off. Is there any reason this wouldn't be OK?

3. Is the sync input rising or falling edge driven? I would be synchronizing the two parallel stages 180 degrees out of phase.

Thanks.

over 8 years ago

0 Mark Pieper over 8 years ago

TI__Expert 4650 points

I should add that with #2 above, I would connect the two COMP pins together so that the master EA would control both stages.

0 Youhao Xi over 8 years ago in reply to Mark Pieper

TI__Guru* 78440 points

Please contact Vijay Choudhary at Vijay.choudhary@ti.com and he has already tested two LM5176 in paralleling.

0 Vijay86929 over 8 years ago in reply to Youhao Xi

TI__Genius 11490 points

Hi Mark,

The buck-boost isn't inherently designed for parallel operation. But there are ways to parallel the parts using external components. I have some material that I sent you on paralleling.

Please note that phase interleaving cannot be achieved in buck-boost mode.

Regards

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LM5176: Parallel operation