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120-355Vdc Input(~Universal AC) 48V/1A Output InnoSwitch & TopSwitch

Posted by: fdroberts2 on

Hello,
I have used your PI Expert Online to create a DC Input (120-350Vdc) 48V/1A output Offline DC Supply schematic. The Tool creates a design for the TopSwitch no problem which is attached. The tool when I select the Innoswitch3-CE produces a 'Design Error' in which it indicates that the Voltage at the FWD pin exceeds 150V? I don't profess myself to be an analog guru especially when it comes to isolated power supplies but I am a bit confused by this error as the FWD pin is on the Secondary side of the transformer which I would think would be well below 150V considering my output voltage is set to 48V? Can one of you PI Gurus help me out here and run a PI Expert Design with the parameters that show in the attached PDF for the InnoSwitch3-CE design and validate whether this error should be a concern or whether it is maybe a misnomer/bug in the design software?

I would much prefer to use the InnoSwitch3-CE because of the UL and EN safety approvals as I don't see these approvals listed for the TopSwitch which is the other PI device that fits into this Power Category. I also like the InnoSwitch3-CE because I don't have to opto-couplers and seems like a simpler design.

This is for a high volume design ~100K so I need to ensure I have the most optimal solution right off the bat.

Regards,
Frank

Comments

Submitted by PI-PIke on 02/14/2018

Hi fdroberts2,

As of now you can't have 48V output on Innoswitch-3 because of the FWD-pin (150V) and Vout-pin (27V) absolute maximum ratings - page 19 of innoswitch-3 spreadsheet. The voltage across the FWD pin will exceed because it is equal to = VAC_Input*(Ns/Np) + Output Voltage.

Regards,
PI-Pike