Electronic circuit to verify the integrity of a switch
The disclosure relates to an electronic circuit to verify the integrity of a switch. The circuit comprises a voltage comparator and decoupling switch. The decoupling switch configured receive the driving signal having a first logic value to enable the monitoring of the comparison voltage and is configured to receive the monitoring enable signal having a first logic value to command the opening of the decoupling switch. The electronic circuit is configured to generate the output monitoring signal having a first logic value in an event that the switch is an open circuit and having a second logic value in an event that the switch is a short circuit.
1 . An electronic circuit to verify an integrity of a switch, the electronic circuit comprising:
a first input terminal adapted to receive a power supply voltage;
a second input terminal adapted to receive a driving signal;
a third input terminal adapted to receive a monitoring enable signal;
a first output terminal adapted to generate an output control signal to drive an opening or closing of the switch;
a second output terminal adapted to generate an output monitoring signal representative of a condition of the switch;
a voltage comparator configured to compare a comparison voltage associated with a terminal of the switch connected to a further power supply voltage with respect to a reference voltage and to generate therefrom the output monitoring signal; and
a decoupling switch interposed between the first output terminal and the second input terminal, the decoupling switch being configured to switch between an open position and a closed position as a function of a value of the monitoring enable signal;
wherein the decoupling switch is configured to:
receive the driving signal having a first logic value to enable the monitoring of the comparison voltage; and
receive the monitoring enable signal having a first logic value to command the opening of the decoupling switch;
wherein the voltage comparator is configured to generate the output monitoring signal having a first logic value in an event that the switch is open and having a second logic value in an event that the switch is closed.
2 . The electronic circuit according to claim 1 , wherein the decoupling switch is configured to:
receive the driving signal having a first logic value to enable the monitoring of the comparison voltage; and
receive the monitoring enable signal having a second logic value to command the closing of the decoupling switch; and
wherein the voltage comparator is configured to generate the output monitoring signal having the second logic value in the event that the switch is closed and having the first logic value in the event that the switch is open.
3 . The electronic circuit according to claim 2 , wherein the decoupling switch comprises:
an input terminal electrically coupled with the second input terminal;
an output terminal electrically connected to a control terminal of the switch;
a control terminal adapted to receive the monitoring enable signal.
4 . The electronic circuit according to claim 3 , further comprising a resistor interposed between the second input terminal and the decoupling switch.
5 . The electronic circuit according to claim 3 , further comprising:
a current generator having a first terminal adapted to receive the power supply voltage and having a second terminal connected to a first terminal of the voltage comparator;
a transistor having a first terminal connected to the first terminal of the voltage comparator and with the second terminal of the current generator, having a second terminal connected to a ground reference voltage and having a control terminal electrically coupled with an input terminal of the decoupling switch.
6 . The electronic circuit according to claim 2 , further comprising a resistor interposed between the second input terminal and the decoupling switch.
7 . The electronic circuit according to claim 2 , further comprising:
a current generator having a first terminal adapted to receive the power supply voltage and having a second terminal connected to a first terminal of the voltage comparator;
a transistor having a first terminal connected to the first terminal of the voltage comparator and with the second terminal of the current generator, having a second terminal connected to a ground reference voltage and having a control terminal electrically coupled with an input terminal of the decoupling switch.
8 . The electronic circuit according to claim 7 , wherein:
the transistor is configured to receive the driving signal having a first logic value to enable the monitoring of the comparison voltage and the transistor is open;
in the event that the switch is open, the voltage comparator is configured to detect that the comparison voltage on one of its negative terminals is greater than the reference voltage on its positive terminal, and the voltage comparator is configured to generate the output monitoring signal having the first logic value indicative of the open circuit of the switch;
in an event of a short circuit of the switch, the current generated by the current generator flows through the switch, and the voltage comparator is configured to detect that the comparison voltage on one of its negative terminals is less than the reference voltage on its positive terminal, and the voltage comparator is configured to generate the output monitoring signal having the second logic value indicative of the short circuit of the switch.
9 . The electronic circuit according to claim 1 , wherein the decoupling switch comprises:
an input terminal electrically coupled with the second input terminal;
an output terminal electrically connected to a control terminal of the switch; and
a control terminal adapted to receive the monitoring enable signal.
10 . The electronic circuit according to claim 9 , further comprising a resistor interposed between the second input terminal and the decoupling switch.
11 . The electronic circuit according to claim 9 , further comprising:
a current generator having a first terminal adapted to receive the power supply voltage and having a second terminal connected to a first terminal of the voltage comparator;
a transistor having a first terminal connected to the first terminal of the voltage comparator and with the second terminal of the current generator, having a second terminal connected to a ground reference voltage and having a control terminal electrically coupled with an input terminal of the decoupling switch.
12 . The electronic circuit according to claim 11 , wherein:
the transistor is configured to receive the driving signal having a first logic value to enable the monitoring of the comparison voltage and the transistor is open;
in the event that the switch is open, the voltage comparator is configured to detect that the comparison voltage on one of its negative terminals is greater than the reference voltage on its positive terminal, and the voltage comparator is configured to generate the output monitoring signal having the first logic value indicative of the open circuit of the switch;
in the event of a short circuit of the switch, the current generated by the current generator flows through the switch, and the voltage comparator is configured to detect that the comparison voltage on one of its negative terminals is less than the reference voltage on its positive terminal, and the voltage comparator is configured to generate the output monitoring signal having the second logic value indicative of the short circuit of the switch.
13 . The electronic circuit according to claim 1 , further comprising a resistor interposed between the second input terminal and the decoupling switch.
14 . The electronic circuit according to claim 1 , further comprising:
a current generator having a first terminal adapted to receive the power supply voltage and having a second terminal connected to a first terminal of the voltage comparator;
a transistor having a first terminal connected to the first terminal of the voltage comparator and with the second terminal of the current generator, having a second terminal connected to a ground reference voltage and having a control terminal electrically coupled with an input terminal of the decoupling switch.
15 . The electronic circuit according to claim 14 , wherein:
the transistor is configured to receive the driving signal having a first logic value to enable the monitoring of the comparison voltage and the transistor is open;
in the event that the switch is open, the voltage comparator is configured to detect that the comparison voltage on one of its negative terminals is greater than the reference voltage on its positive terminal, and the voltage comparator is configured to generate the output monitoring signal having the first logic value indicative of the open circuit of the switch;
in an event of a short circuit of the switch, the current generated by the current generator flows through the switch, and the voltage comparator is configured to detect that the comparison voltage on one of its negative terminals is less than the reference voltage on its positive terminal, and the voltage comparator is configured to generate the output monitoring signal having the second logic value indicative of the short circuit of the switch.
16 . The electronic circuit according to claim 15 , further comprising:
a voltage inverter having an input terminal connected to the second input terminal and an output terminal connected to the control terminal of the transistor;
a resistor having a first terminal connected to the second input terminal and a second terminal connected to the input terminal of the decoupling switch.
17 . The electronic circuit according to claim 14 , further comprising:
a voltage inverter having an input terminal connected to the second input terminal and an output terminal connected to the control terminal of the transistor;
a resistor having a first terminal connected to the second input terminal and a second terminal connected to the input terminal of the decoupling switch.
18 . The electronic circuit according to claim 1 , wherein the decoupling switch is implemented with a MOSFET transistor or with a bipolar junction transistor.
19 . An electronic power supply system comprising:
a switch interposed between a power supply voltage and a ground reference voltage, the switch being configured to switch between an open position and a closed position as a function of a value of an output control signal;
an electronic circuit configured to verify an integrity of the switch, the circuit comprising:
a first input terminal adapted to receive a power supply voltage;
a second input terminal adapted to receive a driving signal;
a third input terminal adapted to receive a monitoring enable signal;
a first output terminal adapted to generate an output control signal to drive the opening or closing of the switch;
a second output terminal adapted to generate an output monitoring signal representative of a condition of the switch;
a voltage comparator configured to compare a comparison voltage associated with a terminal of the switch connected to a further power supply voltage with respect to a reference voltage and to generate therefrom the output monitoring signal;
a decoupling switch interposed between the first output terminal and the second input terminal, the decoupling switch being configured to switch between an open position and a closed position as a function of the value of the monitoring enable signal;
wherein the decoupling switch is configured to:
receive the driving signal having a first logic value to enable the monitoring of the comparison voltage; and
receive the monitoring enable signal having a first logic value to command the opening of the decoupling switch;
wherein the voltage comparator is configured to generate the output monitoring signal having a first logic value in an event that the switch is open and having a second logic value in an event that the switch is closed;
wherein the first output terminal of the electronic circuit is connected to a control terminal of the switch adapted to receive the output control signal;
wherein the electronic circuit further comprises a third output terminal connected to the voltage comparator and adapted to generate said comparison voltage, the third output terminal being electrically coupled with a switch terminal,
wherein the electronic system is configured to operate according to two operating modes:
a test mode, in which the decoupling switch is driven so as to be open or closed as a function of the value of the monitoring enable signal and the electronic circuit is configured to generate the output monitoring signal indicative of the open or closed switch;
a normal operating mode, in which the decoupling switch is closed and the switch is closed and the electronic circuit is configured to generate the output monitoring signal indicative of a normal operating state of the switch or indicative of an overcurrent condition through the switch.
20 . The electronic power supply system according to claim 19 , further comprising a series connection of a resistor and of a diode which are interposed between the third output terminal and the switch terminal.