Using STMicro BAL-NRF01D3 with QFN

[Brian]

I am planning on using the Nordic nRF51822-QFAB-T part. It appears a discrete balun is used for the QFN package on all of the reference designs. Is there a reason that the STMicro BAL-NRF01D3 should not be used in place of the discrete LC network? I only saw the STMicro BAL-NRF01D3 part being used with the BGA package on the reference designs. If it should not be used with the QFN, it would be helpful to understand why not.

[ketiljo]

The ST balun, BAL-NRF01D3, will work only (world wide) with the build code C or older of the QFN packet. As of today, ST doesn't have an alternative for build code D. The balun can be used with build code D of Korean teleregulative approval isn't required.

The CSP uses another balun, the BAL-NRF02D3.

For the QFN version of the nRF51 series, a discrete balun is the standard solution. But this will not be suitable for the CSP as it's simply too large. That's why you'll find only the discrete balun for the QFN even if there are other options available.