基于AD640的大动态范围对数放大器设计

在电子测量领域中,一些信号的电压往往具有很大的动态范围,为了更加方便地测试和分析这些信号,在现代测量接收机的设计中,常常采用大动态范围对数放大器设计技术.本文介绍了一种核心器件为AD640的大动态范围对数放大器的设计,采用3片AD640级联的设计方法,实现了110 dB的动态范围.采用该方法实现的对数放大器动态范围大,电路简单易于实现,对电路参数稍加改动还可实现更大动态范围的对数放大器.实际应用表明,本文给出的设计方法合理有效,有很高的实用价值.

Design of a large dynamic range logarithmic amplifier based on AD640

In the field of electronic measurement, some signals have very large dynamic range. In order to measure and analyze these signals expediently, modern measurement receiver used to adopt a design of large dynamic range logarithmic amplifier. This paper introduced a design of large dynamic range logarithmic amplifier based on AD640, using three AD640s cascaded, with 110 dB of dynamic range at least. Making use of this method, the logarithmic amplifier dynamic range is very large, and besides, this circuit is very simple and effective. By changing some parameters it can also achieve larger dynamic range. The practical applications show that the design method is very valid and practical.