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:

• Microprocessor
• Memory
• Power conversion losses
• Interfaces
  • Display
  • Input/output
    • 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:

• Idle
• Sleep
• Processing
• Transmitting