LM5160-Q1: Inductor value of PMP10733

tateo yamashiro

Guru 10890 points

Part Number: LM5160-Q1
Other Parts Discussed in Thread: PMP10733, LM5160

Hi,

We got a question from the customer about LM5160-Q1.
Could you help us?

[Question]
They are considering using LM5160-Q1 for Fly-buck-boost topology under the following condition.

Vin=8V to 16V
Vo_pri=15.4V
Io_pri=0A
Vo_sec=15V
Io_sec=500mA
fsw=200kHz

They found PMP10733 which is close to their requirement. So they have question.

22uH couplead inductor is used in this design and it makes big inductor ripple. Why is 22uH used in this design?

They are considering using 68uH to 100uH for thier requirement. Because if the small inductance such as 22uH is used, the inductor current reaches the current limit. Is there any concerns about using 68uH to 100uH inductor for thier design?

Best Regards,
tateo

over 7 years ago

0 David Baba over 7 years ago

TI__Mastermind 40040 points

Hello Tateo,

You can use 68uH for this design. no concerns. Just make sure that the saturation level of the coupled inducted used meets the following.

Isat>Ipeak

Where Ipeak= Ipeak (Max) = 2.875A, for the LM5160.

Hope this helps?

David.

0 tateo yamashiro over 7 years ago in reply to David Baba

Guru 10890 points

Hi, Sorry for the delayed reply. Thenk you for your support. We got adddtional question. Could you confirm it?

- How can we determine the ripple injection components in Fly-buck-boost? They checked datasheet and application report(SNVA166A). But these are for the buck convertor. They want to make sure how to determine the components in the case of Fly-buck-boost.

Best Regards,
tateo

0 David Baba over 7 years ago in reply to tateo yamashiro

TI__Mastermind 40040 points

Substitute the following for Equation 8 on page 17.

Vinmin = Vin (min) +Vout, Where Vout = -Vout

Vout = -Vout

Hope this helps?

David.

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LM5160-Q1: Inductor value of PMP10733