Will no external 32.768kHz impact RF performance?

[LeonWu]

Hi team,

We are asked by customer if no external 32.768kHz crystal will impact the RF performance? Customer test and if with internal crystal, that will decrease 3-5m nearer than with external one. Any comments on this?

Thanks!

Leon

[Kenneth]

The 32.768kHz source will have no direct impact on RF performance, however you should ensure that the tolerance when enabling internal LFCLK source is set to 500ppm to account for the additional drift.

[LeonWu]

Hi Kenneth,

They have set the tolerance to be 500ppm, but still have the issue, any other clue on that?

Leon

[Kenneth]

Then I suggest a schematic and layout review. Also possible do an DTM test to verify the BLE performance in total.

Best regards,
Kenneth