A High Level Of Integration Of The Soc Chip Design And Implementation Of - Pmu - 2

As more and more popular the portable devices are getting, personal information terminals, such as mobile phone and tablet pesnoal computer, are developed rapidly too. These devices are mostly single-battery power supply system, in order to meet the various power supply needs of all the modules, the PMU which stands for power management unit is proposed. As more attention are drawn to the market of portable device, research on power management unit is becoming more and more urgent, especially on those applicable in SoC. Compared to the previous single-chip power supply system, power management unit can not only provide multiple power management functions but also has higher levels of integration.To satisfy typical application of mobile device, a high integrated power management unit which is applicable in SoC is proposed. The PMU chip contains four2MHz switching frequency step-dowm converters and two200mA general purpose low drop-out voltage regulators (LDO), an I2C bus has been integrated in this PMU chip and this chip also establish a data communication interface with SoC. The startup sequence of the four step-down converters can be programmed. Through I2C and the register in SoC, one of the step-down converters can performance DVS (Dynamic Voltage Scaling) and some of the analog modules can realize digital calibration. SoC can also read-back the datas in PMU, so it can monitor the working status of PMU more flexibly and accurately. The structure of this PMU chip and some important sub-blocks such as bandgap reference has been introduced in this paper.This chip is taped out in a0.13μm CMOS process, the chip area is4mm2. The PMU is integrated in a low-power SoC chip as an IP. The testing results show that the logical functions such as DVS, start-up sequence and digital correction of the PMU work correctly; The maximum efficiency of the DC-DC converters which can function DVS through I2C is92%and the peak efficiency of the other three DC-DC converters are95%, which satisfies design index.