Title :
A multimode digital detector readout for solid-state medical imaging detectors
Author :
Boles, Colby D. ; Boser, Bernhard E. ; Hasegawa, Bruce H. ; Heanue, Joseph A.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., California Univ., Berkeley, CA, USA
fDate :
5/1/1998 12:00:00 AM
Abstract :
A multipurpose digital detector readout for medical imaging applications is presented. The readout is capable of measuring both current and charge, allowing a single detector array to perform imaging functions previously accomplished with two separate machines. The circuit employs a variable rate ΣΔ analog-to-digital converter (ADC) to measure current over a 130-dB dynamic range in a 1 kHz band and resolve charge pulses down to 360 e- at 100 000 events/s. Detector currents of up to 7 μA and charge pulses as large as 25 fC can be measured. A low-noise charge sensing amplifier (CSA) is combined with digital pulse shaping to optimize the noise performance and flexibility of the charge measurements. Fabricated in an 1.2 μm complimentary metal-oxide-semiconductor (CMOS), the circuit occupies 1.5 mm2 and dissipates 11 mW/channel from a 5 V supply
Keywords :
CMOS integrated circuits; biomedical electronics; biomedical imaging; detector circuits; pulse shaping circuits; sigma-delta modulation; 1.2 micron; 5 V; 7 muA; CMOS; biomedical X-ray imaging; biomedical nuclear imaging; charge sensing amplifier; detector array; detector currents; digital pulse shaping; multimode digital detector readout; radiation detector circuits; solid-state medical imaging detectors; variable rate ΣΔ analog-to-digital converter; Analog-digital conversion; Biomedical imaging; Charge measurement; Current measurement; Detectors; Performance evaluation; Pulse amplifiers; Pulse measurements; Sensor arrays; Solid state circuits;
Journal_Title :
Solid-State Circuits, IEEE Journal of
