CRD-06600FF065N-K

Honbin

Hi, CREE WOLFSPEED,

 

  I am evaluating the reference design of CRD-06600FF065N-K

 the transfer function of DAB-CLLLC is 

  The gain vs frequency plot of CLLLC transfer function illustrates the non-monotonic in the [148kHz, 300kHz] frequency region when I Substitute parameters into the transfer function, as my understanding, which will lead to loss of ZVS on the primary FET, and more critically, the loss of control.

The key parameters of CRD-06600FF065N-K listed below:

   Lrp=9uH, Crp=68Nf, Lm=60Uh, turns ration n=15:14

   The second resonant parameters is identical to the primary.

    my question is why choose this resonant parameters ,and how to make sure the system operation stably.

SiC_Power_Admin

Hello, thank you for your message. A member of our technical team is looking into your questions and we will respond shortly. 

Honbin

Hi, wolfspeed,

i am sorry there is a typo of Ln parameter , the real Ln=Lm/Ln=7, but the gain VS frequency plot is right.

YuequanHu

Honbin,

Thanks for your questions. We'll look into this and get back to you in a few days.

YuequanHu

Dear Huang Bin,

1. The gain vs frequency plot of CLLLC or LLC is always non-monotonic. You just need to make it monotonic in each of your operation region.
2. In your plots, even at the resonant frequency, the gain is less than 1. You need to double check it. at resonant frequency, Gain = 1
3. For resonant tank and Lm design, you need to consider to cover your target operation range.
4. For RL, in this design, the worst cases are A. 430Vin/450Vo G=1.045, 4500W, B. 430Vin/430Vo, G=1 6600W, and C. 395Vin/366Vo, G=0.926, 6600W. 

The design was verified by simulation and actual hardware. 

Honbin

YuequanHu，

I appreciate your reply , you solved my problem.

thank you