Low power design covers a variety of topics. Many low / battery powered designs use low duty cycles to help manage energy usage. A common way to track the overall system power is to create a power budget. This tool is a spreadsheet with a line for each significant component or circuit section.
For example, the following items are in a typical power budget:
- Power conversion losses
- Wireless interface
For each item, include the voltage or voltages. For example, a micro might have one voltage for the core functions, and another voltage for the I/O functions.
On this same line, list the current.
Duplicate this line as needed to represent the other states of the design.
For example, a design might have: