Như các khối xây dựng cơ bản có mức tiêu thụ điện năng tương đối thấp, nhưng với số lượng lớn lên đến một lượng đáng kể quyền lực. Các đơn vị quản lý điện phức tạp nhất (Ban QLDA) được xây dựng ngày nay rõ ràng cho thấy LDOs và chuyển mạch vẫn còn chủ yếu tương tự. Ngày đầu analog truyền thống | More on Power Management Units in Cell Phones 143 Barriers to Up-Integration The power section in a cell phone including the power audio amplifiers and charger is relatively simple it consists mostly of an array of low-power linear regulators and amplifiers. The complexity comes from managing these functions which require reliable data conversion and the additional integration of digital blocks such as SMBus for serial communication and state machines or microcontrollers for correct power sequencing. Such levels of complexity on board a single die bring their own set of problems like interference from cross-talk noise. This new class of power management devices requires technical skills as well as IP and CAD tools which go beyond the traditional power team s skill set and cross into logic microcontroller and data conversion fields. Such an extension of the capability set in the power management space can be a barrier to entry for traditional analog power companies while cost competitiveness will likely be a barrier with which the fab-less startups will have to contend. PMU Building Blocks Highly integrated power management units are often complex devices housed in high pin count packages. Available devices range from 48 to 179 pins. Such units either can be monolithic with perhaps a few external transistors for heavy-duty power handling or multi-chip solutions in a package MCP . The complexity effectively makes these units custom devices. Because of the custom nature of these units the following section will discuss the architecture Figure 6-17 and fundamental building blocks of a PMU in generic terms rather than focusing on a specific device. For the same reasons building blocks will be illustrated by means of available stand-alone ICs. Figure 6-17 illustrates a generic microcontroller-based power management architecture providing all the hardware and software functions as discussed above. Many trade-offs need to be considered when defining this unit. Some of the
