5 Low Power Considerations

For IoT applications, power consumption of an MCU is very crucial. Power consumption is greatly influenced by several factors like operating voltage, the frequency of operation, CPU active period, sleep mode, operating temperature, etc.

In practical applications, usually, the MCU is put into sleep mode while CPU is idle and not performing any active computations. This minimizes the MCU active period to a larger extent. Thereby, the MCU average power consumption reduces, which benefits to attain longer battery life.

Theoretically, average power consumption is calculated by the following formula:

A v e r a g e P o w e r C o n s u m p t i o n = \frac{(A c t i v e C u r r e n t \times A c t i v e P e r i o d) + (S l e e p C u r r e n t \times S l e e p P e r i o d)}{(A c t i v e P e r i o d + S l e e p P e r i o d)}

Here,

Active current is the current consumed by the MCU during active period
Active period is the duration for which the MCU is in active period
Sleep current is the current consumed by the MCU in sleep mode
Sleep period is the duration for which the MCU is in sleep mode