Influence of electrode impedance changes on the common-mode rejection ratio in bioimpedance measurements

1999 ◽  
Vol 20 (4) ◽  
pp. N11-N19 ◽  
Author(s):  
Galidia I Petrova
2017 ◽  
Vol 26 (11) ◽  
pp. 1750169 ◽  
Author(s):  
Francesco Centurelli ◽  
Pietro Monsurrò ◽  
Gaetano Parisi ◽  
Pasquale Tommasino ◽  
Alessandro Trifiletti

This paper presents a fully differential class-AB current mirror OTA that improves the common-mode behavior of a topology that presents very good differential-mode performance but poor common-mode rejection ratio (CMRR). The proposed solution requires a low-current auxiliary circuit driven by the input signal, to compensate the effect of the common-mode input component. Simulations in 40-nm CMOS technology show a net reduction of common-mode gain of more than 90[Formula: see text]dB without affecting the differential-mode behavior; a sample-and-hold amplifier exploiting the proposed amplifier has also been simulated.


2014 ◽  
Vol 488-489 ◽  
pp. 1096-1099
Author(s):  
Tie Feng Wu ◽  
Zhi Chao Zhao ◽  
De Wei Dai ◽  
Shun Ji Piao ◽  
Jing Li

This paper researches the common mode rejection ratio (CMRR) of 3 op-amp instrumentation amplifier of amplifying weak signal and presents a new calculation modal considering noise, non-ideal amplifiers, matched resistor and application restricted by the factors of affecting CMRR. At last, a instrumentation amplifier was designed and built and its measured and computed results of modal are compared. The results show that this modal presented enhances calculating precision and extends application range of instrumentation amplifier. It is valid and reasonable.


The paper proposes a method based on new principle for removal of common mode voltages (CMVs) present in the differential signals # . These CMVs can be reduced nearly to zero without using any components with tight tolerances which is achieved using a new balancing technique. It is proved that the performance of the circuit depends only on the ratios and not on the individual values of the resistors because of which the performance of the circuit is not affected over the wide range of temperature. The circuit based on this principle was designed, constructed, tested and results are reported in this paper. Unlike the conventional techniques which use filters for removal of the common mode signals in specific band of the frequencies, the method reported here removes common mode signals of all known and unknown frequencies. Using this method, it is possible to extract very low values of the differential signals in the range of few microvolts where common mode voltages can be as high as few volts. It is possible to improve the effective common mode rejection ratio (CMRR) of any differential amplifier by a factor of more than 103 to 104 with this method.


2015 ◽  
Vol 23 (18) ◽  
pp. 23859 ◽  
Author(s):  
Xiaoli Jin ◽  
Jing Su ◽  
Yaohui Zheng ◽  
Chaoyong Chen ◽  
Wenzhe Wang ◽  
...  

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