Detection circuit with improved anti-blooming circuit
AssigneeSociete Francaise de Detecteurs Infrarouges-Sofradir
InventorLaurent Baud
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Abstract
The detection circuit comprises a photodiode connected to an input of a capacitive transimpedance amplifier. The circuit comprises an anti-blooming circuit connected between the input and an output of the capacitive transimpedance amplifier. The anti-blooming circuit comprises a field effect transistor connected between the input and output of the capacitive transimpedance amplifier. The transistor is of pMOS type when the input of the capacitive transimpedance amplifier is connected to a cathode of the photodiode. The transistor is of nMOS type when the input of the capacitive transimpedance amplifier is connected to an anode of the photodiode.
Claims11
A detection circuit comprising a photodiode connected to an input of a transimpedance amplifier, an anti-blooming circuit connected between the input and an output of the transimpedance amplifier, the anti-blooming circuit comprising:
- a comparator configured to compare an output voltage of the transimpedance amplifier with a setpoint voltage, and
- circuitry configured to apply a feedback current to the input of the transimpedance amplifier according to a comparison between the output voltage of the transimpedance amplifier and the setpoint voltage.
A method for reading radiation of a detection circuit comprising:
- generating a current from a reverse biased photodiode to an input of a transimpedance amplifier, the transimpedance amplifier having an input and an output connected by a passive element,
- comparing an output voltage of the transimpedance amplifier with a setpoint voltage, and
- generating a feedback current on the input of the transimpedance amplifier according to the comparison between the output voltage of the transimpedance amplifier and the setpoint voltage so as to freeze the output voltage.
Dependencies are inferred from the claim text.