Device for regenerating electronic components in a nuclear environment

A device for regenerating electronic components exposed to ionizing radiation by heating them, wherein it comprises at least the following components:

• a heating resistor intended for heating a component to be regenerated;
• a current source;
• a thermistor connected to said current source and thermally coupled to said heating resistor, said thermistor, through which said current flows, having a voltage Vtemp across its terminals, which voltage reflects the temperature of said heating resistor;
• an error amplifier, which amplifies the difference between a setpoint voltage Vset and the voltage Vtemp and delivers a voltage Vctrl that corresponds to said amplified difference, wherein the error amplifier comprises at least:
• a first differential pair DP2 comprising complementary bipolar transistors, which forms a first amplification stage and receives the voltage Vtemp at a base of one transistor of DP2 and the voltage Vset at a base of the other transistor of DP2;
• a current mirror M4, which fixes a bias current of DP2;
• a second differential pair DP1 comprising complementary bipolar transistors, which forms a second amplification stage, a base of a first transistor of DP1 being connected to a collector of a first transistor of DP2, and a base of the second transistor of DP1 being connected to a collector of the second transistor of DP2;
• a current mirror M3, which fixes a bias current of DP1;
• a bipolar transistor Q2, which forms a third amplification stage, a base of Q2 being connected to a collector of one transistor of DP1, a collector of Q2 being able to be connected to a regulated voltage Vreg, the voltage Vctrl being present at an output of an emitter of Q2;
• a switch, which switches the current flowing through said heating resistor, wherein said switch controls a connection between said heating resistor and a DC supply voltage Vcc;
• an oscillator, which delivers a voltage Vosc formed with a modulated duty cycle, the duty cycle of the pulses of said voltage Vosc being dependent on the voltage Vctrl, said pulses controlling the opening of said switch;
• and
• a safety circuit connected to the oscillator.

A device for regenerating electronic components exposed to ionizing radiation by heating them, wherein it comprises at least the following components:

• a heating resistor intended for heating a component to be regenerated;
• a current source;
• a thermistor connected to said current source and thermally coupled to said heating resistor, said thermistor, through which said current flows, having a voltage Vtemp across its terminals, which voltage reflects the temperature of said heating resistor;
• an error amplifier, which amplifies the difference between a setpoint voltage Vset and the voltage Vtemp and delivers a voltage Vctrl that corresponds to said amplified difference;
• a switch, which switches the current flowing through said heating resistor, wherein said switch controls a connection between said heating resistor and a DC supply voltage Vcc;
• an oscillator, which delivers a voltage Vosc formed with a modulated duty cycle, the duty cycle of the pulses of said voltage Vosc being dependent on the voltage Vctrl, said pulses controlling the opening of said switch, wherein the oscillator comprises:
• bipolar transistors Q5, Q6, Q7, Q8, resistors R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21 and a capacitor C1, which are put together to form a relaxation oscillator, a free-running oscillation frequency being determined by the resistor R12 connected between said capacitor C1 and an emitter of Q8, which forms an output of said oscillator,
• a charging current of the capacitor C1 being controlled so as to modulate the duty cycle of the voltage Vosc delivered at the output of said oscillator, said charging current being supplied by the voltage Vctrl via the resistor R11, the oscillator being powered by a regulated voltage Vreg to which are connected the resistors R13, R14, R15, which are connected to a collector of Q5, Q6 and Q7, respectively, and a collector of the transistor Q8,
• the transistors Q5 and Q6 and the resistors R13, R14, R16, R17 and R19 forming a Schmitt trigger-type flip-flop, a signal across terminals of said capacitor C1 being sent to a base of the transistor Q5 that constitutes the input of said Schmitt trigger-type flip-flop,
• an output of said Schmitt trigger-type flip-flop, formed by a collector of Q6, being sent to an inverter formed by the transistor Q7 and the resistors R15, R18 and R20, R18 being connected between a base of Q7 and a collector of Q6, and R20 being connected between said base and electrical ground, and
• the signal being taken from the collector of the transistor Q7 and being sent to an impedance-matching stage composed of the transistor Q8, connected up as a follower, and the resistor R21, the transistor Q8 and the resistor R21 being configured in common-collector arrangement;
• and
• a safety circuit connected to the oscillator.