Pletronics OHM4

Srdjan Milenkovic s.milenkovic at limemicro.com
Fri Aug 3 14:28:02 UTC 2012


Hi Andrey,

Yes, the best value of Icp will vary with frequency as Kvco is changing. 
Hence, we have option to make look up table or to deign dedicated loop 
filters for the bands of interest. There are no too many bands according 
to Alexander's email, only 4 (effectively 2). Look up table may be more 
flexible solution as you do need to change BOM i.e. hardware platform 
stays the same.

Best regards, Srdjan

On 03/08/2012 14:29, Andrey Sviyazov wrote:
> 1/ Yes, my fears were confirmed - OHM4 footprint isn't correct (my 
> mistake), but it possible to mount from bottom side.
> 2/ Noise plots are similar, I think we see limit of LMS performance 
> but not XO (see pictures here).
>
> Also, I found that for 1850MHz better to use Icp=1.2mA.
> Therefore I decide to measure at 1.2mA for both frequencies just to 
> compare.
> If Icp dependance of frequency confirmed, then we need lookup table 
> for this also.
>
> Best regards,
> Andrey Sviyazov.
>
>
>
> 2012/8/3 Alexander Chemeris <alexander.chemeris at gmail.com 
> <mailto:alexander.chemeris at gmail.com>>
>
>     So, looks like it has a bit worse far-end noise, but otherwise is
>     about the same as TCXO we use now, correct?
>
>     Btw, was it UmTRX layout incorrect or the OCXO pinout?
>
>     On Fri, Aug 3, 2012 at 3:42 PM, Andrey Sviyazov
>     <andreysviyaz at gmail.com <mailto:andreysviyaz at gmail.com>> wrote:
>     > Hi.
>     >
>     > Here LMS TxLO noise plot for OHM4048V-26MHz OCXO.
>     >
>     > Best regards,
>     > Andrey Sviyazov.
>     >
>     >
>     >
>     > 2012/7/31 Andrey Sviyazov <andreysviyaz at gmail.com
>     <mailto:andreysviyaz at gmail.com>>
>     >>
>     >> That's good news!
>     >> Yes, of course, I have to test it and then share some results.
>     >>
>     >> Best regards,
>     >> Andrey Sviyazov.
>     >>
>     >>
>     >>
>     >> 2012/7/31 Alexander Chemeris <alexander.chemeris at gmail.com
>     <mailto:alexander.chemeris at gmail.com>>
>     >>>
>     >>> Hi,
>     >>>
>     >>> I've received 10pcs of OHM4048052GG010020-26.0M today. Andrey
>     Sviyazov
>     >>> - could you measure their performance and test UmTRX with them?
>     >>>
>     >>> --
>     >>> Regards,
>     >>> Alexander Chemeris.
>     >>> CEO, Fairwaves LLC / ООО УмРадио
>     >>> http://fairwaves.ru
>     >>>
>     >>
>     >
>
>
>
>     --
>     Regards,
>     Alexander Chemeris.
>     CEO, Fairwaves LLC / ООО УмРадио
>     http://fairwaves.ru
>
>

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