Method and apparatus for linear low-frequency feedback in monolithic low-noise charge amplifiers

A method of charge amplification, the method comprising the steps of:

• providing a signal amplifier, the signal amplifier comprising an input terminal and an output terminal;
• coupling a first capacitor electrically in parallel across the input terminal and the output terminal of the signal amplifier;
• coupling an inverter operatively to the output terminal of the signal amplifier;
• coupling a current mirror circuit operatively to the input terminal of the signal amplifier;
• and
• coupling a cancellation circuit operatively to the output terminal of the signal amplifier.

A front-end system for use with a radiation sensor, the front-end system comprising:

• a charge amplifier, the charge amplifier receiving a signal from the radiation sensor representing detection of an event, the charge amplifier comprising:
• a signal amplifier, the signal amplifier comprising an input terminal and an output terminal;
• a feedback circuit, the feedback circuit comprising a first capacitor, an inverter, and a current mirror circuit, the first capacitor being electrically coupled in parallel across the input terminal and the output terminal of the signal amplifier, the inverter being operatively coupled to the output terminal of the signal amplifier, the current mirror circuit being operatively coupled to the input terminal of the signal amplifier;
• and
• a cancellation circuit, the cancellation circuit being operatively coupled to the output terminal of the signal amplifier;
• and
• at least one of a current amplifier, a shaping amplifier, a baseline stabilizer, a discriminator, a peak detector, a timing detector, and a logic circuit, the at least one of a current amplifier, shaping amplifier, baseline stabilizer, discriminator, peak detector, timing detector, and logic circuit being operatively coupled to the charge amplifier.