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AD9954 Rev D Eval Brd MiniCircuits part seems rotated

Question asked by shabaz123 on Mar 8, 2011
Latest reply on Mar 9, 2011 by shabaz123

Hello,

 

I'm designing a board, but during PCB layout, I noticed that I could not neatly place my RF transformer without swapping the IOUT and *IOUT wires around, because they cross.

This seemed odd to me, because I had followed the rev D evaluation board schematic and used the same MiniCircuits part (T1-1T-KK81+ as shown in http://www.minicircuits.com/pdfs/T1-1T-KK81.pdf ).

 

Anyway, I looked at the rev D gerber files, and there seems some error. I have attached a snippet of the rev D schematic, which shows pin 21 (IOUT) going to pin 1 of the minicircuits device. I've also attached a snippet of the Minicircuits datasheet, which shows that the round 'Index' mark on the package points to pin 6. However, when I look at the CAD file for the PCB in the gerber viewer, it shows IOUT going to pin 6, not pin 1! I have attached an image of that too, with an arrow showing pin 21 in blue on the left, and the Minicircuits index mark and pin 6 in red colour.

I was wondering, is this a mistake, and was the Minicircuits part actually rotated round in the manufactured board? (I don't have a board to check).

Strictly speaking, even if the part was rotated round, then pin 1 would still not connect to IOUT. It would be pin 3. This means that both the schematic and the PCB legend must be wrong? Should I connect IOUT to pin 3 and *IOUT to pin 1? This would make my layout easier than if I follow the rev D schematic and connect IOUT to pin 1 and *IOUT to pin 3. Would it have any wrong effect? I'm guessing it would be ok and there would be no problem?

 

Many thanks,

Shabaz.

Please see revd_cct.jpgT1-1T-KK81.jpgrevd_pcb.jpg

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