一种RC积分器与比较器构成的廉价型A/D转换器  

Cheap A/D Converter with RC Integrator and Comparator

作　　者：龙顺宇 徐元哲 许禄枝 谢鑫刚 吴路光 Long Shunyu;Xu Yuanzhe;Xu Luzhi;Xie Xingang;Wu Luguang(College of Oceanographic Information Engineering,Hainan Tropical Ocean University,Sanya 572022,China)

机构地区：[1]海南热带海洋学院海洋信息工程学院

出　　处：《单片机与嵌入式系统应用》2019年第11期82-85,共4页Microcontrollers & Embedded Systems

基　　金：省部级-2017年度海南省重点研发项目(ZDYF2017014);海南热带海洋学院2018年校级青年专项基金项目(RHDQN201825)

摘　　要：本文利用RC积分器与电压比较器作为量化核心,实现了一种线性度较好的比较式A/D转换器单元。该单元中电压比较器的同向输入端连接RC积分器,反向输入端连接外部待测电压,在单片机和MOSFET控制下使得RC积分器往复进入零状态响应及充放电过程,经过两输入端的电压比较后得到稳定且连续的翻转波形,随后将其送入单片机定时器中采集脉冲宽度并进行处理,依据脉宽参数反向计算出待测电压值。经测试,在0~30V直流电压段内经补偿处理后的测量精度优于0.5%,可满足一般采集要求,因其电路简单、成本低廉,可作为一种转换方案在相关项目中应用。In the paper,RC integrator and voltage comparator are used as the quantization core to realize a comparative A/D converter unit with better linearity.The non-inverting input terminal of the voltage comparator in the unit is connected to the RC integrator,and the reverse input terminal is connected to the external voltage to be tested.Under the control of the single chip microcomputer and the MOSFET,the RC integrator reciprocates into a zero state response and a charging and discharging process,and passes through the two input ends.After the voltage comparison,a stable and continuous flip waveform will be obtained,and then it will be sent to the MCU timer to collect the pulse width and processed,and the voltage to be measured is calculated inversely according to the pulse width parameter.After testing,the measurement accuracy after compensation processing in the voltage range of 0~30 V DC is better than 0.5%,which can meet the general acquisition requirements.Because of its simple circuit and low cost,it can be used as a conversion scheme in related projects.

关 键 词：RC积分器 零状态响应 电压比较器 A/D转换器 

分 类 号：TP31[自动化与计算机技术—计算机软件与理论]