the datasheet of PR798 (J7) in the BOM of HVPSFB_RvB_bom

Hi Brad,

Thanks for answering me.

so is it available or not?

Hi Nancy,

Appreciate it a lot, it helps.

Hi Nancy,

I had a look and got questions:

1)is this the latest schematic? as I see PIN5 and PIN7 are marked as plus and minus in the schematic, however if you look at the schematic, HVPSFB_REVB_SCH, pin 7 is plus and pin 5 is minus.

please help double check it it is correct.

2)what is the use of output VAUX_PRIMARY(pin3 and pin 4)?

I didn't see anywhere using this other than powering up U1 after the IC gets going, which is powered by VIN via resistors.

Thank you

Hi Harrison,

I have sent your questions to the creator of the reference design.  I will let you know what he says as soon as I hear back.

Unfortunately, I am only the messenger!

Regards,

Nancy

Hi Harrison,

Attached is the updated reference design per your questions.  I hope this helps!

Regards,

Nancy

4300.PR798B Updated.zip

Hi Nancy,

the updated file is the same as you gave me before and it doesn't answer my questions.

Thank you for your help

The schematic was updated: the pin numbers in the schematic did not agree with the specification drawing and the specification drawing did not show pin numbering in the mechanical layout.

Both of these items should have been corrected.  Does this still not help?

Hi Nancy,

I don't quite follow you. are you saying  the pin 5 and pin 7 are wrong?

as said , if you look at the schematic, HVPSFB_REVB_SCH, pin 7 is plus and pin 5 is minus. what do you mean "the specification drawing did nopt show the pin numbering in the mechanical layout?

what about the second question?

Thank you

I think they were wrong and are now corrected.  I am confirming.  Also, getting clarification on your second question.

The schematic did not agree with the specification as to pin numbering. The specification had a board outline, but did not have pin numbers shown. Without pin numbers on the board outline drawing, it is not possible to determine which pin is what pin number. This was corrected in the specification. The schematic was then changed so the pin numbers in the schematic agree with the specification.

As for the question of what the VAUX P voltage is, this is a 12V output capable of providing up to 200mA for primary side components such as drivers and isolators. The combination of current from the VAUX P  and VAUX S outputs should not exceed 0.4A. The voltage is regulated through  transformer coupling from secondary to primary, so the regulation of the VAUX P output will not be as good as the VAUX S, but is still better than 10%.

Hi Nancy,

Currently we working on PR798 PCB. Would you give  PR798 gerber files?

Best regard

Goksel