Electronics

PMIC

In a mobile phone, there is only one power source (usually a battery), but there are a lot of different components pulling out the energy from the battery. Some of the major components would be LCD, Processor/Modem, Memory, RF module and camera etc as shown below.

In many cases, each of those components operate at different voltage levels and consumes different amount of current. Then the question is how to supply the optimum amount of energy without much waste and without influencing the energy supply to other components. You can develop a separate circuits for each components that convert the voltage from the battery to the level that is required for each components, but this implementation would require a lot of jobs and would make the device very bulky as well. So in most of the mobile devices, we use a special IC that is handling this kind of power distribution is called PMIC (Power Management IC). In many case, these PMIC handles not only power distribution, but also some additional function like battery charging and clock distribution. In most advanced form of PMIC, DVFS (Dynamic Voltage and Frequency Scaling) is also implemented by PMIC.

For further reading, refer to following articles.

• Power Management Design for Portable and Battery Powered Systems
• PMICs Solve Complex Power-Management Issues Facing Multicore Processors