Integrated circuit cumulative dose radiation sensor

An integrated circuit comprising:

• an EEPROM cell comprising a floating gate, charging terminals, a ground terminal, and an output terminal, wherein the EEPROM cell is configured to apply a resistance between the ground terminal and the output terminal that varies in response to radiation incident to the floating gate;
• a cell charging circuit connected to the charging terminals and configured to charge the EEPROM cell to apply an initial resistance between the ground terminal and the output terminal;
• a reference resistor connected between the output terminal and a voltage source terminal, wherein the output terminal has a voltage that varies in response to the varying of the resistance applied by the EEPROM cell between the ground terminal and the output terminal;
• a comparator comprising a first input connected to the output terminal and a second input connected to a threshold voltage, wherein the comparator is configured to deliver an output signal in response to the voltage of the output terminal reaching the threshold voltage;
• wherein the cell charging circuit is configured to receive the output signal from the comparator and to recharge the EEPROM cell to apply the initial resistance in response to receiving the output signal from the comparator;
• and
• a counter configured to count a number of times the comparator delivers the output signal.

A method comprising:

• setting a resistance of a cell between a ground terminal and an output terminal to an initial resistance;
• varying the resistance of the cell cumulatively in response to incident radiation, wherein a voltage of the output terminal varies as a function of the resistance of the cell;
• delivering an output signal in response to the voltage of the output terminal reaching a threshold voltage;
• resetting the cell to the initial resistance in response to the output signal;
• and
• counting a number of times the output signal is delivered.