nRF905 oscillator accuracy

[Sabia]

Hi,

I am designing a system that will include an nRF905 transceiver. How accurate should the nRF905 oscillator frequency be for each receiver/transmitter in order to ensure good transmission? Is there for instance a benefit of going for a 30ppm instead of 50ppm? Will it be even better to improve the accuracy even further, to, say 10 or 1 ppm? At what accuracy level is there no benefit to increasing the accuracy of the oscillator/crystal?

Thanks!

[Øyvind Karlsen]

Hi,

The product specification for nRF905 states that you must use oscillators that are +/- 30 ppm or better for 868/915 MHz use and +/- 60 ppm or better for 433 MHz use. The nRF905 supports both crystal and external MCU reference, in both cases the accuracy should be as described above. If the crystal accuracy is below that of the spec, the device will not function according to spec and might not work at all.

Go for the crystal that is within spec and fits your Bill of Material.

In a final product you also need to pass a complicance test, the limitations can be found in the Regulatory and Compliance Standards whitepaper

Best regards,

Øyvind