传感器系统的高精度Hybrid ADC的研究与设计

Design of a high resolution Hybrid ADC for sensor system

介绍了一种应用于传感器检测系统的高精度Hybrid ADC,此系统是基于双积分ADC与SAR ADC的混合结构。详细描述了此结构提出的理论基础、电路的具体结构,并基于此结构设计了一款16位Hybrid ADC,此系统的时钟频率为25 MHz,输入电压范围为0.5 V^4.5 V,电源电压为5 V。仿真结果显示,此结构的16位ADC的信噪比达到90 d B,有效位数可达到15位,而且仅用了28个时钟周期实现了16位ADC的转换,此结构既有双积分ADC的高分辨率的特点,还部分继承了SAR ADC的速度优势。

This paper presents a new architecture of Hybrid ADC based on SAR ADC and dual slope ADC used for sensor system. Based on this architecture, the 16 bits A/D converter was designed, which has a system clock frequency of 1 MHz for a supply voltage of 5 V with an input voltage from 0.5 V to 4.5 V. The SNR of the ADC can reach 90 dB, effective bit is about 15 bits. What＇s more, it only takes 28 times the period of clock faster than 216 times the period of clock of the traditional dual slope ar- chitecture. This architecture not only can reach higher resolution than dual slope analog-to-digital converter but it＇s conversion speed greatly accelerate due to the adoption of SAR architecture.