1. Noise Performance of a Regulated Cascode Transimpedance Amplifier for Radiation Detectors.
- Author
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Oliveira, Luis B., Leitao, Carlos M., and Silva, M. Medeiros
- Subjects
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ACOUSTIC impedance , *ELECTRONIC amplifiers , *ELECTRIC potential , *POSITRON emission tomography , *FEEDBACK control systems , *ELECTRONIC circuits , *RANDOM noise theory - Abstract
A low noise transimpedance amplifier (TIA) is used in radiation detectors to transform the current pulse produced by a photo-sensitive device into an output voltage pulse with a specified amplitude and shape. We consider here the specifications of a PET (positron emission tomography) system. We review the traditional approach, feedback TIA, using an operational amplifier with feedback, and we investigate two alternative circuits: the common-gate TIA, and the regulated cascode TIA. We derive the transimpedance function (the poles of which determine the pulse shaping); we identify the transistor in each circuit that has the dominant noise source, and we obtain closed-form equations for the rms output noise voltage. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
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