UCC256403: LLC transformer design

Ilia Hadzhiev

Part Number: UCC256403

Hello,

I am in designing transformer in LLC configuration. The procedure i follow is attached below.

1. How come to choose deltaB = 0.62 T, there will be enormous losses in the core ? I have chose 0,232T considering the losses in the core and also the window factor ( windings turns ).
2. Is it appropriate to play with the value of Cr ( LLC ) to adjust the desired inductance Lm of the transformer ?( After i have calculated the turns i adjust the Cr value to get a magnetizing inductance value with which i will have reasonable air gap. )

over 4 years ago

0 Ilia Hadzhiev over 4 years ago

Prodigy 230 points

0 Pye Naing over 4 years ago in reply to Ilia Hadzhiev

TI__Prodigy 590 points

Hello, your thread has been assigned. You should receive a reply shortly.

0 Yunsheng Qu over 4 years ago

TI__Genius 9790 points

Hi, Ilia

1. Which document are you refering to when to calculate the transformer? I think it is not datasheet of UCC256403. Normally, the deltaB should be less than 0.3T.

2. it is appropriate to change Cr to get different Lm and Lr with same resonant frequency of resonant tank.

Br,

Yunsheng

0 Ilia Hadzhiev over 4 years ago in reply to Yunsheng Qu

Prodigy 230 points

Hello,

i realized from where is coming the misunderstanding, the vendors gives graphs for losses vs Bmax. I though they give graphs for losses vs deltaB and from there are coming the big losses. Anyway thank you for the reply it was helpful.

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UCC256403: LLC transformer design