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ACDC Power Supply 220Vin AC -5Vout DC @100mA, ISOLATED but with NO transformer?

Antonio Faggio
Expert 7920 points
Other Parts Discussed in Thread: TPS7A78, UCC28881

Hi,

I got a customer request for which I cannot answer.

He is requesting a power supply for AC/DC 220Vin AC, 5Vout DC, Iout 100mA, better if isolated and in this case they want to avoid transformer since it is costly.

If we also have intergrated PFC or cheap external PFC to add it is a pro.

Do you have anything to propose here?

80% of the time customer does not need isolation, but once he needs he does not want to use a transformer.

I was also thinking of ACDC LDO TPS7A78, but this does not have isolation.

I am confused by customer question.

Many Thanks,

Antonio

  • 0
    TI__Guru* 86266 points

    Hello,

    The TPS7A78 is for non isolated designs?

    You can easily do this with a flyback converter.

    Generally PFC is not needed for less than 75W for general applications.  I think lighting requires PFC at 25 W greater.  So I am not sure why you customer needs a PFC.

    If the customer is just looking for an offline high side buck.  You could use the UCC28881 with and integrated FET.

    Regards,