UCC28950/about inductor current dispersion in interleave

Tsukui Yusuke

Guru 21930 points

Other Parts Discussed in Thread: UCC28950, UCC39002, UCC29002

Hi,

Could you tell me about inductor current dispersion in interleave.
Customer is troubled with the dispersion of the inductor current.
I have got three questions from customers.

1.Which parameter influences the dispersion of the inductor current?
2.Could you tell me Information with the dispersion of the inductor electric current?
3.DC offset voltage seem to affect the inductor current.
Please tell me the variation of this offset voltage(typ=0.85V).

Please give me some advice.

Best Regards,
Yusuke/Japan Disty

over 8 years ago

0 John Stevens over 8 years ago

TI__Expert 7395 points

Yusuke-San,
What do you mean by "dispersion"? Are you referring to cancellation when doing multiple phases and the inductor ripple current out of phase cancels?
Regards
John

0 Colin Gillmor over 8 years ago in reply to John Stevens

TI__Mastermind 25570 points

Hello Yusuke-San

I think most of your question is answered by the thread at https://e2e.ti.com/support/power_management/isolated_controllers/f/188/t/455062

Two UCC28950 devices may be connected to share current using the circuit below.

You may also find the files at

http://www.ti.com/lit/gpn/ucc28950

http://www.ti.com/litv/pdf/slua560c

http://www.ti.com/litv/zip/sluc222b

useful.

Please let me know if I have missed anything or if you have any further questions on this.

Regards

Colin

0 John Stevens over 8 years ago in reply to Colin Gillmor

TI__Expert 7395 points

Hello Yusuke-San,
Colin has good feedback here. the only thing I would add-when using 2 UCC28950's in parallel as master and slave, you want to be sure you are using them both in peak current mode control, not voltage mode so that they balance the current better between them. additionally, you could consider using a load share controller like UCC39002 or UCC29002 to help share them.
Regards,
John

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UCC28950/about inductor current dispersion in interleave