High-energy suppression for infrared imagers or other imaging devices

An apparatus comprising:

• a photodetector configured to generate an electrical current based on received illumination;
• an integration capacitor configured to integrate the electrical current and generate an integrator voltage;
• an amplifier configured to control a transistor switch coupled in series between the photodetector and the integration capacitor;
• an event detector configured to sense a high-energy event affecting the photodetector;
• and
• a switchable clamp coupled across inputs of the amplifier, the event detector configured to close the switchable clamp in response to sensing the high-energy event;
• wherein the event detector is configured to close the switchable clamp in order to maintain a desired reverse bias voltage on the photodetector during the high-energy event.

A system comprising:

• a focal plane array comprising multiple optical detectors;
• wherein each of the optical detectors comprises:
• a photodetector configured to generate an electrical current based on received illumination;
• an integration capacitor configured to integrate the electrical current and generate an integrator voltage;
• an amplifier configured to control a transistor switch coupled in series between the photodetector and the integration capacitor;
• an event detector configured to sense a high-energy event affecting the photodetector;
• a switchable clamp coupled across inputs of the amplifier, the event detector configured to close the switchable clamp in response to sensing the high-energy event;
• and
• a de-bias protection diode coupled to an output of the amplifier and to a gate of the transistor switch, the de-bias protection diode configured to limit a skew of a signal generated by the amplifier for the gate of the transistor switch.

A method comprising:

• generating an electrical current based on received illumination using a photodetector;
• integrating the electrical current to generate an integrator voltage using an integration capacitor;
• controlling a transistor switch coupled in series between the photodetector and the integration capacitor using an amplifier;
• sensing a high-energy event affecting the photodetector;
• in response to sensing the high-energy event, closing a switchable clamp coupled across inputs of the amplifier;
• and
• limiting a skew of a signal generated by the amplifier for a gate of the transistor switch using a de-bias protection diode coupled to an output of the amplifier and to the gate of the transistor switch.