Design and Characteristics of a Multichannel Front-End ASIC Using Current-Mode CSA for Small-Animal PET Imaging

Abstract

This paper presents the design and characteristics of a front-end readout application-specific integrated circuit (ASIC) dedicated to a multichannel-plate photodetector coupled to LYSO scintillating crystals. In our configuration, the crystals are oriented in the axial direction readout on both sides by individual photodetector channels allowing the spatial resolution and the detection efficiency to be independent of each other. Both energy signals and timing triggers from the photodetectors are required to be read out by the front-end ASIC. A current-mode charge-sensitive amplifier is proposed for this application. This paper presents performance characteristics of a 10-channel prototype chip designed and fabricated in a 0.35-μm complementary metal-oxide semiconductor process. The main results of simulations and measurements are presented and discussed. The gain of the chip is 13.1 mV/pC while the peak time of a CR-RC pulse shaper is 280 ns. The signal-to-noise ratio is 39 dB and the rms noise is 300 μV/√(Hz). The nonlinearity is less than 3% and the crosstalk is about 0.2%. The power dissipation is less than 15 mW/channel. This prototype will be extended to a 64-channel circuit with integrated time-to-digital converter and analog-to-digital converter together for a high-sensitive small-animal positron emission tomography imaging system.

A novel data acquisition scheme based on a low-noise front-end ASIC and a high-speed ADC for CZT-based PET imaging

“…9. It is indicated that the proposed scheme can achieve better nonlinearity performances than that of the traditional method which samples the energy voltage by using an analog memory and a monostable circuit [5]. The nonlinearity of the traditional peak-detect-and-hold method versus the proposed data acquisition scheme.…”

“…The peak value of the shaped voltages are sampled by a peak-detect-and-hold circuit [5]. The triggers are achieved by a high-speed high-resolution discriminator.…”

An analog front-end ASIC with programmable gain and timing for silicon photomultiplier arrays

“…A number of integrated circuits with the number of channels up to 128 have been developed for readout and processing signals of SiPM cells and arrays [18][19][20][21][22][23][24][25][26][27][28][29]. Most of them are designed for application in medical scanners, and multi-channel detectors of physical installations.…”

A new feedback circuit based charge-pump for wide-range and low-jitter DLL suitable for PET imaging applications

“…This emitted positron upon combining with nearby electron produces two back-to-back photon of 511KeV energy. This photon pair is detected by scintillator and APD [1]- [6]/PMT [7]- [8] based detector module. For APD based detector module [1] the signal is processed by charge sensitive amplifier (CSA), pulse shaper, discriminator, peak detector and hold circuit.…”