Title :
Input characteristics of a chopped multi-path current feedback instrumentation amplifier
Author :
Fan, Qinwen ; Huijsing, Johan ; Makinwa, Kofi
Author_Institution :
Tech. Univ. Delft, Delft, Netherlands
Abstract :
This paper presents simulations and measurements of the input impedance, input bias and offset current of a chopped multi-path current feedback instrumentation amplifier. In precision applications, these parameters, together with a finite impedance source can lead to significant measurement errors. In this paper, design strategies to minimize these errors are provided. At a chopping frequency of 30 kHz, the proposed amplifier has an input impedance of 6 MΩ, with bias and offset currents of 102pA and 43pA, respectively. In addition, it achieves low noise (21nV/√Hz), low (2 μV) input-referred offset, high common-mode rejection ratio (134dB) and high power supply rejection ratio (120dB).
Keywords :
choppers (circuits); electric current measurement; electric impedance measurement; feedback amplifiers; instrumentation amplifiers; low noise amplifiers; chopped multipath current feedback instrumentation amplifier; common-mode rejection ratio; current 102 pA; current 43 pA; finite impedance source; frequency 30 kHz; input bias measurement; input impedance measurement; low noise Amplifier; measurement error; noise figure 120 dB; noise figure 134 dB; offset current measurement; power supply rejection ratio; resistance 6 Mohm; voltage 2 muV; Measurement errors; Time frequency analysis;
Conference_Titel :
Advances in Sensors and Interfaces (IWASI), 2011 4th IEEE International Workshop on
Conference_Location :
Savelletri di Fasano
Print_ISBN :
978-1-4577-0623-3
Electronic_ISBN :
978-1-4577-0622-6
DOI :
10.1109/IWASI.2011.6004688
