一、前言在自动检测、控制系统中,为了将低电平输入讯号精确地放大,对放大器中的某些指标,诸如漂移,增益等技术指标提出较高的要求。而这些指标的完成,按目前国内组件制造水平,是颇难实现的。DF—1运算放大器如图1,它是在线性组件 BG305前加一级差分放大器构成。其温漂可小于0.5μV/C,增益大于10~6,目前已广泛使用于 DD—Ⅲ温度变送器中,本文通过将该放大器应用于数字温度计的实践,进行理论分析。 I. Preface In the automatic detection and control system, in order to accurately amplify the low-level input signal, some of the indicators in the amplifier, such as drift, gain and other technical indicators put forward higher requirements. The completion of these indicators, according to the current level of domestic component manufacturing, is quite difficult to achieve. DF-1 op amp shown in Figure 1, which is composed of a linear differential amplifier BG305 front plus one. The temperature drift can be less than 0.5μV / C, gain greater than 10 to 6, has been widely used in DD-Ⅲ temperature transmitter, the amplifier through the application of digital thermometer practice, the theoretical analysis.