Design recommendations when using

WLCSP34 package

AN4630

Figure 24: RF ground on the discrete balun application board

To design the board with the integrated balun as matching network all the above

suggestions has to be implemented. The only difference is located in the balun zone where

the datasheet recommendation has to be followed. Particular attention to the ground must

be observed: also in this case the RF ground in the TOP layer is “hot” and it could generate

pulling. The RF TOP layer ground has to be extended to the balun zone (see Figure 25:

"RF ground on the integrated balun application board "), but has to be merged to the other

ground on the INNER3 layer.

Figure 25: RF ground on the integrated balun application board

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