The Design And Implementation Of The Waveform Analyzer's Analog Dual-channel And Control Of Storage-depth

With the development of the Electronic test and measurement technology, test tools are toward intelligent, digital and network direction. Waveform analyzer grows up with the development of digital signal processing technology, it is a kind of new electronic measurement equipment with characteristics of high-speed data acquisition, storage, display, analysis and processing functions. Waveform analyzer as digital storage oscilloscope, the main performance indicators is bandwidth, sample rate and memory depth.This design mainly talk about the waveform analyzer's analog dual-channel and control of the storage depth design and implementation.Firstly, we will introduce analog dual-channel's design and implementation, Analog channel is an important part of the waveform analyzer. It is good or bad direct relationship to the waveform analyzer's performance. External signals in the analog channel do some conditioning before sent to ADC to quantify, So how to make analog channel with higher bandwidth, less interference and better AC and DC characteristics as the sticking point of the design.The part of the analog channel's design and testing which mainly related to coupling selection module, attenuation circuit module, impedance conversion circuit module, weak attenuation of the circuit module, amplifier circuit module and the differential amplifier module, and use ARM microcontroller to control the analog channels and achieve coordination of each module, In the design we first use multisim software to analysis the function of the different module, and take some measures to prevent noise from disturbing analog circuits. Eventually the original input signal can through the analog channel and maintain the basic features, also meet the requirements of the signal acquisition module.Secondly, we design the control of the storage-depth, Waveform analyzer's storage-depth is an important symbol of the performance, the size of the storage-depth is essential to analysis the high frequency signal's low-frequency modulated and low frequency signal's high-frequency noise. In this design, we use the Altera's FPGA CycloneⅢfamily EP3C25Q240 constitute the ARM+FPGA structure as design platform. Using FPGA to realize the control of the SDRAM, and use the different bit wide asynchronous FIFO as a buffer realize real-time data storage to ensure the data can be uninterrupted storage in the high sampling rate..The article systematic research of the analog dual-channel and the control of storage-depth, and do some corresponding validation, the experiment prove this design basically meet the requirements.