UCC28600: Designing the transformer to match the circuit from WEBENCH®︎ POWER DESIGNER

Hi, Roger:

Thanks for asking. 

Normally the transformer is customized to different power rating. It's hard to estimate the system form factor to us. So the web designer only provide the necessary inductance and turn ratio information here. 

The user can choose the core and check if the core and bobbin size can meet the system form factor or not. 

The most close reference design is PMP10816. It is a 48V/200Wflyback with universal AC input. 

As your power is 576W, it is needed bigger transformer core for this power rating. 

Is there any special reason that you choose UCC28600 for this power? 

Frankly speaking, the output power is 576W (48V*12A), normally it is 480W (48V/10A). Flyback topology is not suitable for this power range. It can do but it needs very big transformer since the peak current is high. According to this

2 stage solution (PFC + LLC ) would the one candidate for this power rating. If it is okay to you, UCC28180 (PFC controller) + UCC256402 (LLC controller) might be more suitable for this power rating.  

Thanks.

Regards, 

Wesley

Thanks for your great answer!
I chose the UCC28600 because it was suggested to me by the tool.
But for these circuits I have a similar problem. For the UCC28180DR I don't get any requests for a complete circuit part.
All red components come without values or similar. Can I assume that L2 is only for signal decoupling so has a winding ratio of 1:1?
The rest of the circuit seems pretty good. And understandable for me.

With the UCC256402DDBR it looks there against better there is however again a transformer with very little data.
Do I understand it correctly that you need here in principle a transformer with ratio 1:1 which has an impedance in the specified range and can withstand 12A ?
Or is even a low current sufficient? because here the voltage is even higher or is worked with high frequency?

I would be very happy to hear from you again
Best regards
Roger

Hi, Roger:

For UCC28180, the L2 is used to be an EMI filter. So generally it would 1:1 ratio with high inductance to be a pi- filter with CX1 and CX2 to filter high frequency noise. Since it is hard to estimate the noise, system did not show the inductance in this moment. 

For UCC256402, the transformer shows the Ns1 : Np = 0.25 and Ns2:Np = 0.25. So the turns ratio would Np:Ns1:Ns2 = 4:1:1. 

And yes, the inductance and resonant capacitor are specified by 48V/12A.  Since the each user may choose different core for there system form factor, it did not show the core and turns for each winding. It is a general idea for the output rating. The calculator UCC25640X calculator would provide more detail setting based on the system requirement. 

The refer design of TIDA-01494 is very similar to your power rating. The only different is its output is only 24V. However, it would be okay by the modification of LLC's transformer turns and LLC IC setting to meet 48V output.  You can refer TIDA-01494's PFC choke of UCC28180 design based on the power rating. 

The another thing is, LLC controller of TIDA-01494 is previous one, UCC25630.  UCC25640X series would be our newest controller for LLC topology. For UCC25640X's schematic, you may refer the PMP22087. 

I am sorry that we have no reference design to put UCC28180 and UCC25640x together. However, it should be still good reference here to you. 

We still have lots of reference design here.  TI reference design  It should provide some idea to you. 

Regards, 

Wesley