LM5017 Fly-buck inductor current wave form during Toff

tateo yamashiro

Other Parts Discussed in Thread: LM5017

My customer has questions about LM5017 Fly-buck topology.
Could you tell me about questions.

[Questions]
- During Toff, the inductor current wave form is curve.
Why is the current wave form curve?

- When low input voltage operation, the inductor current wave form is straight.
Why is the inductor current wave form straiht?

- Which is better, curve or straight?

Please show attached file.

6116.Questions.pptx

Best regards,

tateo

over 10 years ago

0 Timothy Hegarty over 10 years ago

TI__Guru 74472 points

Hello Tateo,

The current has a resonant profile based on the fly-buck transformer / coupled inductor leakage inductance. At low VIN (high duty cycle), the 1-D conduction time may become short relative to the applicable resonant period and the behavior is not quite as noticeable (more linear waveform).

Regards,

Tim

0 Vijay86929 over 10 years ago

TI__Genius 11490 points

Hi Tateo,

This document has a detailed waveforms and information on Fly-Buck operation.

http://www.ti.com/lit/an/snva674b/snva674b.pdf

Regards

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LM5017 Fly-buck inductor current wave form during Toff