LM5175: I'm wondering the LM5175 chip can use in parallel for a 3.5KW output

Hello user6322596,

For 2 converters in parallel, I would recommend following the solution in this app note: LM5176 Power Sharing Between Two Parallel, Four-Switch Buck-Boost Converters (ti.com)

For further phases you would need to add further OpAmps and reference all to the same signal from the first phase. Altough I think it might be possible, I think it will be difficult to realize as small changes in the reference signal might come already just because you need to do a layout that is not 100% the same for all converters.

BTW, for 8 phases you should synchronize the converters with an external phase shifted clock.

What is your input voltage? Possibly the boost converter LM5170 fits your needs here better.

Best regards,
Brigitte

hi, Brigitte

   Thanks for your reply.

   I'll check your advice carefully and then evaluate the feasibility of the case.

   I"ll reply in two days.

hi, Brigitte

   sorry for the delay.

   I've read the application note carefully. And I agree with your opinion that for more than 2 or 4 phae's application, it's quite difficult to kepp the layout symmetrically to keep the accuracy of power share and aviod the disturbance of other signals.

   And the input Voltage range is around 20V ~ 70V. the max current may over 100A. As for the output voltage, is 24V and 48V.

   From the LM5170 spec and EVM. I just find the Buck or Boost topology, I want to know that is the LM5170 can meet my need.

   Thanks.

Hello Feng,

LM5170 is buck in one direction and boost in the other. This means it cannot fill your need of buck and boost in the same direction. This is a pitty.as it is easily stackable.

Maybe you might think about a resonant converter, similar to this reference design: PMP20978 reference design | TI.com

I will forward your thread to a team that possibly has the better controllers for such a high power design.

Best regards,
Brigitte

Hello Brigit,

This is not a device that HVC generally supports.  I will forwarded to someone who can figure it out.

Regards,

Hello Brigit and Feng,

The LM5170 is a bidirectional controller.  You might be able to do this with a C2000 or a UCD3138.  If you have any questions regarding these devices please repost in the e2e with C2000 and UCD3138 in the thread title.  So the appropriate applications engineer can answer these questions for you.

Regards,

Mike O

hi, Mike

   It seems the solution of C2000 and the UCD3138 belongs to DSP or Digital contorllors. It is a band-new area for me and I nerver did this before.

hi, Brigitte

   I notice that the 2 phase parallel solution use the LM5176, and I wanna comfirm that the LM5175 can do the same thing.