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[color=rgb(34, 34, 34)][font=arial]Hi all, I'd like to calculate the noise figure of the board for the rx part and [/font][/color][color=rgb(34, 34, 34)][font=arial]in particular the LNA that is at the beginning of the chain. In the datasheet there is a lna_out port, unfortunately I haven't been able to find a pin with such name. Any clue about this? Anyone knows where to find the datasheet for the LNA? [/font][/color][/size]

Dear Sir,


The LNA component is a SKY67101-396LF and the pin mapping is at the following:


1 N/C
2 RFIN
3 RFGND
4 VIN
5 FEEDBACK
6 N/C
7 RFOUT/VDD
8 N/C
9 Thermal Pad


There is a serie RC (R=51Ohm and C=3.3pF) between pin 7 and pin 5.


Best Regards,
Arnaud

[quote author=arnaudNL link=topic=2500.msg13007#msg13007 date=1386060230]
Dear Sir,


The LNA component is a SKY67101-396LF and the pin mapping is at the following:


1 N/C
2 RFIN
3 RFGND
4 VIN
5 FEEDBACK
6 N/C
7 RFOUT/VDD
8 N/C
9 Thermal Pad


There is a serie RC (R=51Ohm and C=3.3pF) between pin 7 and pin 5.


Best Regards,
Arnaud
[/quote]


[size=2]Thanks a lot for your answer, my doubt is that we are using a FMC30RF board with rf coverage between 1200 MHz -3000 MHz, so I'd like to know if my board use the [font=Verdana]SKY67101-396LF or another LNA due to differnent RF. [/font][/size]
[size=2][font=Verdana]In the [/font][font=Verdana]FMC30RF[/font][font=Verdana]  datasheet ther is a [/font][font=Verdana]LNA_OUT pin (it's written that it's not avaiable from the front panel) but, if possible, I'd like to measure it's output, how can I measure it?[/font][/size]
[font=Verdana][size=2]Best regards,[/size][/font]
[font=Verdana][size=2]Giovanni[/size][/font]

Dear Giovanni,


You have a FMC30RF with high range option. I checked the BOM and the exact LNA part number is SKY6710-396LF. The low range option has a SKY67101-396LF instead. I don't have direct link to the datasheet unfortunately; The FMC30RF was driven by Texas Instruments, they had a RF development board and we have been asked to redesign this board as an FMC board keeping the same components on the board.


The lna_out signal goes on some resistors but they are all caged by the Faraday cage and removing the metal casing is not an option.


Best Regards,
Arnaud

[quote author=arnaudNL link=topic=2500.msg13016#msg13016 date=1386069275]
You have a FMC30RF with high range option. I checked the BOM and the exact LNA part number is SKY6710-396LF. The low range option has a SKY67101-396LF instead.
[/quote]


Dear Arnaud,


I think there is missing a number in the LNA reference: SKY6710[b]X[/b]-396LF


See the next pdf with the LNA family. Depending on that last number the target frequency is very different:
http://www.skyworksinc.com/uploads/documents/bro394_12.pdf


Can you tell me the exact part number?


Best regards,
Jose

Jose,


Sorry for that, the complete part number is SKY67100-396LF


Best Regards,
Arnaud

Thanks Arnaud,


But that LNA operating frequency range is only 1.7-2.0 GHz.


Best regards,

Dear Jose,


Well, depends if you look at the preliminary datasheet (http://www.cdiweb.com/datasheets/skyworks/201265C.pdf) or the actual current datasheet (http://www.skyworksinc.com/uploads/documents/SKY67100_396LF_201265I.pdf) from Skyworks directly.


I do feel that a bit odd but I cannot imagine the designer to be so light. Also you should know Texas Instruments driven this design. They have asked us to port a huge RF board (or two) they had into FMC form factor, schematics were reviewed by TI and the board was characterized by TI so I would not expect such a design flaw.


Best Regards,
Arnaud

Ok, thanks for references Arnaud

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