Development Of Digital Multi-channel Pulse Amplitude Analyzer

Multi-channel pulse height analyzer (MCA) is an instrument for measuring the signal pulse amplitude distribution, is an important part of the spectrum analyzer. With the rapid development of high-speed ADC technology and digital signal processing technology, the digital pulse amplitude analyzer (DMCA) is gradually replacing position of analog multi-channel analyzer (AMCA). DMCA holds a strong advantage in the measurement accuracy and measurement speed.The purpose of the subject is measuring radiation, the use of programmable logic devices (FPGA) and MCU (STM32) combined dual-core controller program complete digital multi-channel pulse analyzer designed indexing. High-speed ADC+FPGA combination of analog signal peaks whole collection method, maintain signal integrity initial information; trapezoidal shaping algorithm for nuclear pulse signal processing, the information obtained the highest efficiency. Selecting Altera’s CYCLONE IV series FPGA--EP4C10E144C8N, STM32 is selected STMicroelectronics Introduces ARMCortex-M3 core-based microcontroller--STM32F103ZET6, AD’s AD9245 is selected to front-end of high-speed digital to analog converter. The system power supply design is completed according to the product level requirements. Trapezoidal shaped digital filtering algorithm for nuclear pulse signal processing, in order to improve the performance DMCA. The trapezoidal shaping filter design modular design, adjustable parameters in real time and to do in order to achieve the flexibility and portability of work. FPGA as a digital signal processor using nuclear pulse data, all functions is implemented within the FPGA. FPGA using Verilog HDL language to complete the internal control module design, divided into high-speed AD sampling control module, trapezoidal shaped module, in addition to noise SPI modules stacked modules, peak search module, as well as spectral module and STM32 communications. STM32 is the controller of the system, and the controller of memory (FLAH, SRAM), improved communication with the FPGA to complete the transfer of data and commands through improved SPI.Finally, using software simulation and simulation experiments to test and verify the accuracy and stability of the system. The performance parameter of DMCA is measured by measurement tools, and the measurement meets performance requirements.