LM5050-2: Protection for -58V PoE

Lutz Naumann

Part Number: LM5050-2

Dear team,

we are planning to use LM5050-2 an a PoE application. Therefore we need -58V protection similar to the -48V example shown in the datasheet figure 25.

Please advice which modifications are necessary to achieve the desired protection. Or would you have a different recommendation.

many thanks

Lutz

over 6 years ago

0 Karikalan Selvaraj over 6 years ago

TI__Genius 16305 points

Hi Lutz,

I am looking into this question and will get back at the earliest.

Regards,
Kari.

0 Karikalan Selvaraj over 6 years ago in reply to Karikalan Selvaraj

TI__Genius 16305 points

Hi Lutz,

In Figure 25 of LM5050-2 datasheet, Change D3 to 80V 1A schottky diode, SS18 from OnSemi, if the negative voltage expected is lower than -60V.

On the positive side, Cout capacitance is rated to 63V, and if the application max is greater than 63V, change it accordingly. If the max voltage go beyond 75V, then change input capacitance as well.

Regards,
Kari.

0 Lutz Naumann over 6 years ago in reply to Karikalan Selvaraj

TI__Expert 6110 points

Thanks Kari,

I need to share some schematic with you but would take this offline. So I'm sending a separate email to you directly.

thanks

Lutz

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LM5050-2: Protection for -58V PoE