摘要
提出一种基于TDC(时间数字转换)的微小电容测量电路的设计方案。该电路具有功耗低、体积小、抗干扰性强、分辨力高、刷新率高的特点。详细阐述了测量电路的基本原理、具体实现、参数配置、标定和抗干扰设计,并且通过测量0pF～3pF范围的固定电容和动态电容验证了电路的性能。试验表明电路在10Hz刷新频率下分辨力为6aF;电路在13kHz刷新频率下分辨力为610aF;ENOB(有效精度位)最高可达22位。
A circuit design plan for measuring micro-capacitance based on TDC （time to digital conversion） is proposed. This circuit has some prominent features such as low power, small volume, strong anti-interference ability, high resolution and high update rate. Basic principle, detailed implementation, parameter configuration, calibration and anti-interference design of capacitance measurment circuit are described detailedly. Measurements of static and dynamic capacitance in 0 pF to 3 pF show that the circuit has a good performance with resolution of 6aF in 10Hz update rate and 610aF in 13kHz update rate; and the ENOB（effective number of bits） is up to 22 bits.
出处
《电子技术应用》
北大核心
2010年第1期71-74,78,共5页
Application of Electronic Technique
基金
山西省自然科学基金(2008011026-2)
关键词
TDC
微小电容
抗干扰
标定
TDC
micro capacitance
anti-interference
.calibration
