In this paper, we present the design and preliminary results of a novel low-noise front-end readout application-specific integrated circuit (ASIC) for a PET imaging system whose objective is to achieve the following performances: the spatial resolution of mm , the detection efficiency of 15% and the time resolution of 1 ns. A cascode amplifier based on the PMOS input transistor is selected to realize the charge-sensitive amplifier (CSA) for the sake of good noise performances. The output of the CSA is split into two branches. One is connected to a slow shaper for energy measurements. The other is connected to a fast shaper for time acquisition. A novel monostable circuits is designed to adjust the time delay of the trigger signals so that the peak value of the shaped voltages can be sampled and stored. An eight-channel front-end readout prototype chip is designed and implemented in m CMOS process. The die size is mm mm. The input range of the ASIC is from 2000 e-to 180000 e-, reflecting to the energy level of the gamma ray from 11.2 keV to 1 MeV. The gain of the readout channel is 65 mV/fC. The tested result of ENC is 86.5 e-at zero farad plus 9.3 e-per picofarad. The nonlinearity is less than 3%. The crosstalk is less than 2%. The power dissipation is about 3 mW/channel.

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In this paper, the design of a novel low-noise front-end readout circuit for Cadmium zinc telluride (CdZnTe) X-ray and γ-ray detectors is described. The front-end readout circuits include the charge sensitive amplifier (CSA) and the CR-RC shaper is implemented in TSMC 0.35 μm mixed-signal CMOS technology. The die size of the prototype chip is 4.9 mm × 2.2 mm. The simulation results show that, the noise performance is 46 electrons + 10 electrons/pF, and power consumption is 1.65 mW per channel.

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In this paper, we present a novel data acquisition scheme based on a low-noise front-end readout ASIC and a high speed ADC for PET imaging systems based on cadmium zinc telluride (CZT) detectors. A charge-sensitive amplifier(CSA), a pulse shaper and a driving buffer are integrated for each CZT detector pixel. The specifications of the ASIC are dependent on the dimension of the CZT detector. Eight shaping voltages are sampled and digitized. The data from the ADC is collected by a programmable FPGA which can run an algorithm to calculate the peak value of the shaped voltages and the trigging timing of the shaped pulses. To achieve good noise performances and to realize a flexible front-end electronic system, the front-end ASIC and the ADC are not integrated together. Two ASICs as well as the FPGA chip will be bonded directly on the board. Both the front-end readout chip and the ADC chip are designed in 0.35 μm CMOS processing. The input range of the front-end ASIC is from 2000 e-to 40000 e-. The equivalent noise charge (ENC) is below 200 e-. The shaping time is about 1.5 μs. The simulated results show that the proposed method can achieve good spatial resolution and good detection efficiency, and meanwhile, the time resolution of the PET system is greatly improved.

This paper proposes a novel exponential anti‐windup method for a high‐proportional‐load marine electrical propeller system, allowing the system to respond to changes in working conditions that would make the control system operate in the open‐loop state and severely affect the system stability and dynamic response speed. First, the commonly used inverse calculation type and conditional integration type anti‐windup methods are discussed, and the two methods are compared and analysed. The proposed exponential anti‐integral saturation method is obtained by introducing an exponential link in the PI controller to weaken the effect of the integral link when the controller output is saturated to improve the control performance of the traditional anti‐integral saturation method when the operating conditions of the marine electrical propeller system change. To verify the accuracy of the theoretical analysis, experiments were conducted using starsim. The experimental results verify that the theoretical analysis and parameter design are correct and superior and have the characteristics of fast desaturation and small overshoot of the system. The method has good theoretical research significance and practical application prospects for improving the comprehensive performance of marine electrical propeller systems.