UCC2897A: How does the main MOS implement soft switch.

dushimutong

Intellectual 620 points

Part Number: UCC2897A

Hello

Please help me.

Active clamp

How does the main MOS implement soft switch.

How to design.

UCC2897 datesheet and application file has not introduced.

Thank you very much.

Regards

Neil

over 8 years ago

0 Peter Meaney over 8 years ago

TI__Mastermind 31580 points

Hi Neil,

Thank you for your interest in the UCC2897 device.

There are a couple of papers on the Active Clamp forward on the following TI page, www.ti.com/.../login.shtml. Hopefully these should be of use to you.

Regards

Peter

0 dushimutong over 8 years ago in reply to Peter Meaney

Intellectual 620 points

Hello
Peter Meaney
I have read, and did not specify how to set the parameters to achieve the soft switch
Regards
Neil

0 Oliver Pan91 over 8 years ago in reply to dushimutong

TI__Intellectual 2230 points

Active clamp technique uses LC resonance to realize soft switching. To achieve LVS(low voltage switching) or ZVS, a proper arrangement of energy flowing becomes a key design point in active clamp technique. The energy stored in the Cds of FET has to be diverted out by the magnetic inductor or leakage inductor before starting each switching cycle. This requires the magnetic inductors or leakage inductor has enough energy to flow out the electric energy in Cds to the magnetic. Detailed analysis please refer to this article: Design Guidelines on the Effect of Resonant Transitions of Forward Converter on Efficiency with Active Clamp

0 dushimutong over 8 years ago in reply to Oliver Pan91

Intellectual 620 points

Hello Oliver Pan91
Thank you very much.
I have read this article, or can not systematically design active clamp, for example,
1: How is Ieq in Equ.13?
2: how to set the primary leakage inductance of the transformer.
Regards
Neil

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UCC2897A: How does the main MOS implement soft switch.