Calculation method of power consumption of microcontroller

The power consumption of a microcontroller is very difficult to calculate, and at high temperatures, the power consumption of a microcontroller is a particularly important parameter.

For the time being, the power consumption of the microcontroller is divided as follows.

1. Internal power consumption (related to frequency)

2. Power consumption of digital input and output ports

2.1 Input port

2.2 Output High

2.3 Output Low

3. Analog input power consumption

Some basic parameters can be derived from the table below:

First, we calculate the internal power consumption. The power consumption of a microcontroller is generally related to the operating frequency. At a fixed frequency, it is related to the function. There are two ways to calculate it.

The first one is fixed frequency, and the increase and decrease function causes the current to change:

The second type is frequency change, regardless of the module used:

Secondly, calculate the power consumption of the digital port:

For digital output ports, according to the data in the table, the internal Rdson can be obtained, and the internal power consumption of output high and output low can be calculated.
It should be noted here that the power consumption of the input port is generally not large, but the power consumption of the designed IO port is relatively large when current is injected. At this time, the clamping diode is working, so pay attention to this part of the power consumption.

P=I.inject*Vf_diode

The input power consumption is relatively small when there is no clamping. If the input voltage is too high or too low, it will cause many problems.

The total power consumption of the MCU is the sum of three parts.

P.MCU=P.internal+P.IO+P.Analog