A power-efficient, low-noise, wideband, integrated CMOS preamplifier for LSO/APD PET systems

• Published in: IEEE transactions on nuclear science 2000-06, Vol.47 (3), p.810-817
• Main Authors: Binkley, D.M., Puckett, B.S., Casey, M.E., Lecomte, R., Saoudi, A.
• Format: Article
• Language: English
• Subjects: Amplifiers (electronic); Avalanche diodes; Capacitance; Design optimization; Detectors; Electric potential; Electrical capacitance tomography; Energy resolution; Gamma rays; Methodology; Noise; Optimization methods; Photodiodes; Positron emission; Positron emission tomography; Preamplifiers; Radiation detectors; Time measurements; Timing; Transconductance; Voltage; White noise; Wideband
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/23.856522

A power-efficient, low-noise, wideband, 0.8-/spl mu/ CMOS charge-sensitive preamplifier has been designed and optimized for LSO/APD based PET systems. Low-noise, wideband performance is needed to achieve 1-ns FWHM timing resolution available from LSO/APD detectors, and power efficiency is needed since thousands of preamplifiers are required in a LSO/APD based PET tomograph. A methodology for optimizing wideband timing performance is presented to minimize dominant, frequency-turn-up, input-noise current associated with input noise voltage and total capacitance at the input. The methodology suggests the use of a nMOS input device operating in moderate inversion for high transconductance and low input white-noise voltage consistent with moderate input capacitance. Measured preamplifier input-referred, white-noise voltage is 0.65 mV//spl radic/Hz and risetime is 6 ns (58 MHz 3-dB bandwidth). Measured timing resolution is 1.15 ns FWHM and energy resolution is 12.1% FWHM for 511-keV gamma rays detected by a 4/spl times/4/spl times/10 mm LSO crystal coupled to an APD. Measurements include the APD capacitance of 30 pF and are obtained at a preamplifier input-device current of only 2 mA.