A fully integrated power-management solution for a 65nm CMOS cellular handset chip

For cellular handset ICs, integrating the power management unit (PMU) in the same chip as the baseband and the radio is critical for footprint and cost reduction, however, it presents unique challenges in terms of device reliability, bill of materials (BOM) and PMU performance. In this paper, a PMU integrated as part of a GSM/EDGE chip in a 65nm deep-Nwell CMOS process, comprising a battery charger, a regulated inverting charge pump, multiple regulators, and a White LED (WLED) driver is presented. The battery charger supports various charging profiles up to VCHG=12V and can tolerate up to 20V. A regulated charge pump (CP) operating directly from the battery (V_BAT) provides negative supply for earphone class-AB audio power amplifiers (APA) for ground referred headset connectors. A buck converter and several linear regulators supply the various sub-systems on the chip as well as external modules (SIM Card/Camera/Interfaces etc.). An inductive-boost WLED driver drives up to 6 LEDs in series or up to 3 in parallel.