RF Bluetooth front end circuitry design of nRF51822 QFAA-G0

[Fenglong]

According to Page5 of nWP-018, if we compare QFAA G0 to C0, G0 doesn't have a valid version reference design with the right balun. But G0 and C0 have the same valid reference design with LC matching network.

So how to explain that the reference LC network design works for both G0 and C0, but the balun only works for C0 and not G0? Are there any difference in the Nordic chip's RF frontend?

thanks, Fenglong

[ovrebekk]

Hi Fenglong

This is covered by item 61 in the nRF51822 PAN: www.nordicsemi.com/.../12268137

Basically you can get too high RX LO leakage with the latest revision of the nRF51822, which could make the RF qualification fail.

Most likely an updated balun from ST will have to be released that will fix the issue, the exact timing for this is still TBD.

Best regards Torbjørn

[Guest]

thank you Torbjørn. the issue is answered.