0217.docx

ADI 0217
关键字:工业控制,测试仪表, 阻抗测量
0217采用12位阻抗转换器AD5933/AD5934. AD5933是1MSPS的12位ADC,而AD5934是250KSPS的12位ADC,内部集成了温度传感器(±2°C),%,-,图1的电路优化了信号链,其阻抗测量范围从低欧姆数到几百kΩ,主要用在电化学分析,生物阻抗分析,复数阻抗分析,生物和汽车传感器,接近式检测,非破坏性检测,以及材料特性分析和燃料/, 功能方框图, 病毒株血样本测量框图和AD5933评估板主要特性,电路图与材料清单.
The AD5933 and AD5934 are high precision impedance converter system solutions bine an on-chip programmable frequency generator with a 12-bit, 1 MSPS (AD5933) or 250 kSPS (AD5934) analog-to-digital converter (ADC). The tunable frequency generator allows an plex impedance to be excited with a known frequency.
The circuit shown in Figure 1 yields accurate impedance measurements extending from the low ohm range to several hundred kΩ and also optimizes the overall accuracy of the AD5933/AD5934. 

The AD5933 is a high precision impedance converter system solution bines an on-board frequency generator with a 12-bit, 1 MSPS, analog-to-digital converter (ADC). The frequency generator allows an plex impedance to be excited with a known frequency. The response signal from the impedance is sampled by the on-board ADC and a discrete Fourier transform (DFT) is processed by an on-board DSP engine. The DFT algorithm returns a real (R) and imaginary (I) data-word at each output frequency. 
Once calibrated, the magnitude of the impedance and relative phase of the impedance at eac