双通道100 MSPS数据采集板卡设计

Dual channel 100 MSPS data acquisition module design

针对目前国内对宽带隔离高精度数字示波器的急迫需求,研究设计了一款双通道12位100 MSPS的数据采集板卡,用作示波器的前端采集板卡。该板卡由无源衰减电路、阻抗变换电路、偏置电路、可变增益电路、ADC驱动电路、触发电路、隔离电路、核心器件ADC与FPGA芯片等组成。重点研究了宽带阻抗变换电路、电路低噪声设计、高隔离设计等,编写相应的程序后,对电路板的带宽、采样率、隔离度、数据传输等关键指标进行测试,通过测试性能指标满足设计要求,设计的采集板卡能够适用于目前各测试场合。

In view of the urgent need for broadband isolation high-precision digital oscilloscopes in China, a dual-channel 12-bit 100 MSPS data acquisition board was designed and used as the front-end acquisition board of the oscilloscope. The board consists of a passive attenuation circuit, an impedance conversion circuit, a bias circuit, a variable gain circuit, an ADC drive circuit, a trigger circuit, an isolation circuit, a core device ADC and an FPGA chip. The research focuses on broadband impedance conversion circuit, circuit low noise design, high isolation design, etc. After writing the corresponding program, it tests the key parameters such as bandwidth, sampling rate, isolation and data transmission of the board, and meets the design through test performance indicators. Requirements, the design of the acquisition board can be applied to the current test occasions.