This application note will discuss several techniques available to help limit the power consumption. To illustrate this, a conceptual application is introduced, and the techniques will be applied to this application.
The conceptual application is a very simple application that monitors an external temperature sensor connected to a pin. In its basic form, the application busy-spins for one second then measures the value of the sensor using the Analog-to-Digital Converter (ADC) and compares this value to two predefined threshold values. Two threshold values are used to create a window, in order to avoid constant switching. Based on this comparison several actions can be taken, i.e. turn the heater OFF if the temperature is above the upper threshold value, or turn the heater ON if the temperature is below the lower threshold value. As long as the temperature is inside the window, no adjustments will be made. For simplicity, in this application, these actions are turning a pin ON or OFF.