DocID024134 Rev 2

11/17

AN4232

Application examples

16

powered on, and the analog input voltage is measured. When the sensor output is lower

than the threshold, the MCU re-enters the low-power mode to save battery life.

Enabling the ADC only when required (analog voltage higher than a threshold) dramatically

reduces the average power consumption, as compared to an application where the ADC is

always enabled whatever the analog voltage.

Note:

When an external signal needs to be monitored within a certain voltage range or window,

Window mode can be used. In this mode, the non-inverting inputs of comparators COMP1

and COMP2 are connected together and the input signal must be connected to the non-

inverting input of COMP1.

In STM32F30x devices, Window mode is available for COMP3/COMP4 and

COMP5/COMP6.

Figure 6. Current consumption in an analog voltage monitoring application