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CC1101 26MHz CRYSTAL PROBLEM !!!

The question was asked on the TI forum.

Dear Community Members,

I have a big problem about the 26MHz crystal oscillator. I am a electronic hardware design enginner in a water meter factory. On our AMR (868MHz RF) water meter’s PCB we are using CC1101 transceiver. In the first 10K pieces of production we used 26MHz crystal with 20pF internal load capacitance (27pF capacitors were on the each pin of the crystal).  Our handheld terminals have this crystal too. We are using 26MHz crystal with 16pF load capacitance since the first production. For getting the true matching between crystal’s load capacitance and capacitors on each pin of crystal we changed the capacitors from 27pF to 20pF. They are working well too. But the problem is the handheld terminals do not communicate with the new PCBs(with 16pF load capacitance crystal). I think there is a channel shift. The PCB have same specifications, same layout, same schematic. The embedded software(in MSP430F2121) is same. And the register settings of the CC1101 is same too. Everything is same. The only difference is crystal (crystal’s load capacitance) and the capacitors connected to the pins of crystal. Does anybody help me? Thank you very much.

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Performance Issues with CC2500EMK

This question was posted on e2e.ti.com:

I have a CC2500EMK (old design:Chipcon 1.0) the firmware runs perfectly well when this emk is attached with the module(performace is good) but when attach my own emk using the new CC2500EMK 062 reference design from the ti user guide  the performace is really is causing concern with high PER.

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32.000MHz Crystal for CC2430

This question was posted on e2e.ti.com:

My company have designed and are now manufacturing circuits using the CC2430 in a similar circuit to the reference design. Quantities are still relatively small (runs of 500 – 1000) but we are having great difficulty sourcing the 32MHz NX3225SA crystal at the 10/15/30/16 spec. We can get 15/15/30/8 very easily and am not too worried about the initially accuracy being 15 instead of 10. The switch to the 8pF load crystal is more of a problem. I can change C15/16 from 33/27pf to 15/15pf and so the crystal should still work but are there any other possible problems? How will this affect the RF accuracy? Will the circuit still meet the IEEE specs?

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