Electronic monitoring circuit for detecting the variation in the power or current absorbed by at least one electronic circuit under test and electronic system for testing the operation of the at least one electronic circuit

An electronic system for testing the operation of an electronic circuit, the system comprising:

• an electronic monitoring circuit for detecting a variation in the power or current absorbed by an electronic circuit under test, the electronic monitoring circuit comprising;
• an input terminal configured to receive a pulse-width modulation control signal, wherein said control signal is configured to control opening and closing of at least one power switch of a switch mode power supply of the electronic circuit under test;
• a resistor having a first terminal connected to the input terminal;
• a capacitor having a first terminal connected to a second terminal of the resistor and having a second terminal connected to a low reference voltage;
• and
• an output terminal configured to generate an output signal as a function of value of the voltage drop between the terminals of the capacitor, said output signal being representative of a variation in the pulse width of the pulse-width modulation control signal, wherein said variation in the pulse width is a function of power or current absorbed by the electronic circuit under test;
• a driving device connected to the electronic monitoring circuit and configured to generate the pulse-width modulation control signal;
• the electronic circuit under test;
• a switch mode power supply connected at the input to the electronic driving device and at the output to the electronic circuit under test, the switch mode power supply comprising:
• an input terminal configured to receive the pulse-width modulation control signal;
• an output terminal configured to generate a power supply signal of the electronic circuit under test;
• and
• at least one power switch configured to switch between an open and a closed position, as a function of the value of the pulse-width modulation control signal;
• a processing unit connected to the electronic monitoring circuit, the processing unit being configured to receive as input the signal representative of the variation of the pulse width and generate, as a function of the comparison between the signal representative of the variation of the pulse width and an expected value, a diagnosis signal representative of a correct operation or of an incorrect operation of the electronic circuit under test, wherein said expected value is associated with the power or current absorbed by the electronic circuit under test under a defined operating condition of the electronic circuit under test,
• the electronic monitoring circuit comprising:
• a further resistor having a first terminal connected to the input terminal;
• a further capacitor having a first terminal connected to a second terminal of the further resistor and having a second terminal connected to the low reference voltage;
• wherein:
• the output terminal of the electronic monitoring circuit is configured to generate the output signal as a function of the difference between the value of the voltage drop between the terminals of the capacitor and the value of the voltage drop between the terminals of the further capacitor;
• and wherein, alternatively:
• the resistance value is equal for said resistor and said further resistor and the capacitance value differs between said capacitor and said further capacitor;
• the resistance value differs between said resistor and said further resistor and the capacitance value is equal for said capacitor and said further capacitor.