Data Readout Method And Circuit Research Based On The Waveform Sampling Technology

Compared with the traditional data readout method, the waveform sampling data readout method has broad application prospects because of its high system integration, simple circuit structure and multi-parameter measurement with a set of circuit, etc. The traditional waveform sampling technology based on flash ADC(FADC) has been widely used in particle physics experiments. But for the reason of its power consumption, cost and the complexity of circuit, it has already unable to meet the demands of development of modern particle physics experiments. The new waveform sampling technology based on switched-capacitor arrays(SCA) has great advantages in cost, power consumption, and so on, which is one of the important future development direction in particle physics experiments. At present, the research and application of waveform sampling technology based on SCA have been launched at home and abroad in succession.As the progress of semiconductor technology, integrated circuit design and computer technology, the technology of application specific integrated circuit(ASIC) is becoming maturing gradually. Several ASICs based on SCA have been developed abroad and successfully applied in particle physics experiments. The research of waveform sampling technology based on SCA is still at the initial stage in our country. The main work is the research and application of DRS4 designed by Paul Scherrer Institute(PSI).Based on the team’s previous research, further research for application of DRS4 has been done in this paper. The existing waveform digitization front-end circuit exchanges data with upper computer through USB bus, and its dead time is about 248?s, which limits the application scope of this circuit in particle physics experiments. In order to solve these problems, we improved and redesigned this circuit. The dead time of improved circuit is reduced to 31?s. Through optic fiber, the improved circuit can realize long-distance transmission for large amount of data. Meanwile, according to the design requirements, a high-speed data acquisition system was designed and implemented. The system consists of waveform digitalization front-end circuit, high-speed data transmission circuit and upper computer software. Four waveform digitalization front-end circuits can be connected to high-speed data transmission circuit, which makes the whole system having 32 analog input channels. High-speed data transmission circuit and upper computer exchange data with PCI Express bus. The function for endpoint-initiated Direct Memory Access(DMA) data transfers was designed in high-speed data transmission circuit. The high-speed data acquisition system can be applied in particle physics experiments requiring high sampling rate and long-distance transmission for its low dead time, high sampling rate, high input bandwidth and high data transmission rate. The performance of improved waveform digitization front-end circuit has been evaluated in detail, and preliminary test of the highspeed data acquisition system has been performed.