基于FPGA具有自动量程转换功能的信号采集电路设计

随着被测信号动态范围的扩大,测量仪器必须具备自动量程功能,由此本文提出了一种具有自动量程功能的信号采集电路的设计方法。基于逐次比较的思路,该电路利用模拟电路对信号进行识别,通过FPGA控制继电器切换至合适量程,从而实现自动量程功能。在实际测试中,该电路能对信号进行快速、准确量程识别,有效保证了测量精度。因此该采集电路适用于电压表、示波表等测试仪器信号采集部分的设计,并且具有成本低、结构简单、稳定可靠的特点。

Design of automatic range switching circuit of signal acquisition based on FPGA

With expanding of the dynamic range of measured signal,the test instrumentation must have the function of automatic range switching.This paper presents a method to design signal acquisition circuit with the function of automatic range switching.Based on successive comparison of ideas,the circuit uses analog circuits for signal identification,and controls relay switches by FPGA to the appropriate range,enabling automatic range switching function.In actual testing,the circuit can realize fast,accurate range recognition of measured signal,would effectively guarantee the measurement accuracy.This circuit applies the design of signal acquisition part of test instrumentation such as voltmeter,oscilloscope,and has the characteristics of low costs,simple structure,reliability and stability.