Many electrical devices use multiple internal voltages (e.g., 5 V, 3.3 V, 1.8 V, etc.) and sources of external power (e.g., wall outlet, battery, etc.), meaning that the power design of the device has multiple requirements for operation. A PMIC can refer to any chip that is an individual power related function, but generally refer to ICs that incorporate more than one function such as different power conversions and power controls such as voltage supervision and undervoltage protection. By incorporating these functions into one IC, a number of improvements to the overall design can be made such as better conversion efficiency, smaller solution size, and better heat dissipation.[2]