针对标准电压源的高失调性、低稳定性等缺陷,提出了一种高精度精密电压源的实现方案.通过标准电压源的生成过程分析基准电压源对数模转换器的要求,进而选择20位高精度数模转换器AD5791.重点阐述了其电路的设计方案,并结合AD5791的硬件特性和软件设置克服了以往数模转换器作为基准源的高失调现象.对实验数据进行测试表明,该方案具有线性度高、稳定性好的优点,能输出0~10 V连续电压且其输出精度可达0.02 mV,线性度高达99.996%,能够满足高精密电压源的设计要求.
Aiming at the high imbalance, low stability of the standard voltage source, the implement scheme of a high precision voltage source was put forward in this paper.The 20 bit high precision analog-to-digital converter AD5791 was selected through analyzing the requirement of the digital-to-analog converter for the generation process of the standard voltage source reference voltage source.The design scheme of the circuit was presented and the high imbalance phenomenon of the past D/A converters as a reference source was overcome by combining the AD5791 hardware features and software settings.The test of the experimental data showed that the proposed scheme had advantages of high linearity and good stability.The 0~ 10 V continuous voltage can be output with the precision of 0.02 mV, and the linearity is up to 99.996%.It can satisfy the design requirements of high precision voltage source.