Multi-channel pulse amplitude analyzer circuit design based on S3C2440

Industrial Router Crystal 3.2*2.5mm 3225 26M (26.000MHZ) 12PF 10PPM 20PPM 30PPM

Photocoupler

Overview:
The traditional multi-channel pulse amplitude analyzer with single chip as the core has low integration, difficult hardware and software design, and difficult system upgrade. This paper introduces a hardware design scheme of multi-channel pulse amplitude analyzer based on high-performance 32-bit embedded processor S3C2440 processing. The circuit mainly includes screening circuit, peak expansion circuit, control circuit and A/D conversion circuit. The discriminating circuit removes the low-energy noise signal by setting the threshold, the peak detecting circuit performs the peak position detection and the peak expansion of the input signal, and the A/D conversion circuit realizes the analog-digital conversion of the input signal. The control circuit precisely controls the working timing of the entire circuit. Tests show that the system has good differential nonlinearity and integral nonlinearity, fast speed, good stability and can be used in practical work.

The multi-channel pulse amplitude analyzer is an important component of the nuclear radiation measuring instrument. It divides the measured pulse amplitude range into n amplitude intervals equally, then measures the count value of the input pulse in each amplitude interval, and finally obtains the input. The relationship between the pulse amplitude of the signal and the corresponding count. The traditional multi-channel pulse amplitude analyzer mostly uses the 51 series single chip as the core circuit system. Due to the limited processing power of the microcontroller, this instrument requires software support from the host computer. The design of the upper and lower position machines also defines the function of the system, which affects the stability and real-time of the system. In addition, the low integration of the single-chip system also makes the system design difficult and the system upgrade difficult. In this paper, a multi-channel pulse amplitude analyzer design scheme based on 32-bit ARM 9-core S3C2440 processor is proposed. The design can collect, analyze, process and display nuclear signals. It is a multi-channel pulse amplitude analysis system with high integration, high precision, low power consumption and low cost.

1 system overall hardware structure system design scheme shown in Figure 1, the hardware circuit is mainly composed of screening circuit, peak detection circuit, A / D conversion circuit and S3C2440 peripheral expansion circuit. System working principle: The nuclear pulse signal output from the nuclear detector is divided into two ways. All the way into the discriminating circuit, the circuit selects the waveform of the signal, and sets the threshold voltage of the input pulse to eliminate the low-energy noise. The other signal enters the peak extension circuit, which detects the peak arrival time and broadens and maintains the peak of the pulse to a width that can accommodate the A/D conversion time. The control circuit controls the operation timing of the entire hardware circuit and precisely starts the A/D conversion. After the signal A/D conversion is completed, the S3C2440 uses the interrupt mode to read the conversion result, uses the conversion result as the address value, and increments the count value of the address. After an input pulse signal is processed, the S3C2440 issues a gate signal to return the control circuit to its initial state, waiting for the next pulse to arrive. After a period of measurement, a pulse-amplitude curve of the signal is obtained. The touch screen of the S3C2440 peripheral interface circuit can realize the control and operation of the entire system. The LCD display is used to display the energy spectrum and data processing results. The data information is optionally stored in a USB device for subsequent processing by the computer.

Figure 2 Screening diagram (please read the PDF for details)