Hello Jeff,

Thanks for reaching out to us via e2e.

The word "inputs" may be a bit misleading here.

It does not refer to the input voltage. It refers to the combination of the parameters that you have entered (your inputs to the tool).

The reason why the tool does not accept the combination of your parameters is a hard limit of 50W output power for a Flyback design.

At more than 50W the losses of the transformer are considered as too high.

In reality it can surely work wit 54W as well, but the transformer may become bulky and expensive.

Therefore, if Isolation is not required, other topologies should be preferred.

When I enter 0.92A @ 54V this will result in a Total Output Power of 49.73W and you will get the design created.

When I then try to increase it to 0.93A it tells me that the maximum output power has been exceeded.

By the way, we have a reference design which is getting close to your requirements. But the output current is rated for 0.75A.

See here:

https://www.ti.com/tool/PMP9446#overview

Best regards,

Harry

Hi Harry,

The output of PMP9446 reference design is 54V/0.75A.

Since the Coilcraft Flyback Transformer NA6264-AL is 48W (48V/1A) can the output of PMP9446 reference design be increased to 54V/0.88A?

Thanks!

Jeff

Hello Jeff,

It is not good to design a system in a way that there is no margin left (for any of the components).

So, if you need to get close to 1A I would suggest using a different transformer.

Best regards,

Harry

Hi Harry,

Got it, let me check with my customer. thank you!

Jeff

Hi Harry,

Do you know there have PMP9446 EVB can buy from TI website?

or you have this EVM board on hand can help us test for 54V/0.88A condition?

Thanks!

Jeff

Hello Jeff,

I am sorry, but as you can read on our website:
A fully assembled board has been developed for testing and performance validation only, and is not available for sale.

Gerber files, BOM, schematics, etc are available for free, so the customer can easily get a board bult.

Best regards, 
Harry

Hi Harry,

Sure, thanks for your support.

Jeff