-GSM baseband-radios system-on-chip (SoC) fabricated in CMOS technology are well established on the market. The next evolutionary step on the proceeding integration path is the extension of the baseband-radio functionality by further integration of power-management-unit (PMU) functionality. This PMU of a mobile phone is normally realized as a separate chip. The integration of the PMU promises lowest phone cost, eases PCB design, reduces phone development time, and enables overall system optimization. However, several integration challenges have to be tackled. An SoC is presented for which the aforementioned challenges were successfully managed. The achieved performance will be demonstrated with corresponding measurement results.