Title :
Ultrastable low-noise current amplifier
Author :
Drung, Dietmar ; Krause, Christoph ; Becker, Ulrich ; Scherer, Hansjorg ; Ahlers, Franz J.
Author_Institution :
Phys.-Tech. Bundesanstalt, Berlin, Germany
Abstract :
An ultrastable low-noise current amplifier (ULCA) is presented. The ULCA is a non-cryogenic instrument based on specially designed operational amplifiers and resistor networks. It acts as a current-to-current amplifier or a current-to-voltage converter. Its transfer coefficient is extremely stable versus time, temperature and current amplitude within the full dynamic range of ±13 nA. The concept aims at achieving an uncertainty of one part in 107 at direct currents of 100 pA. A cryogenic current comparator is used to calibrate both current gain and transresistance, providing traceability to the quantum Hall resistance. A low noise level of 2.4 fA/√Hz helps to keep averaging times low at small input currents.
Keywords :
calibration; circuit noise; cryogenic electronics; current comparators; electric current measurement; gain measurement; low noise amplifiers; operational amplifiers; power convertors; resistors; ULCA; calibration; cryogenic current comparator; current 100 pA; current measurement; current-to-current amplifier; current-to-voltage converter; gain measurement; noncryogenic instrument; operational amplifier; quantum Hall resistance; resistor network; transfer coefficient; ultrastable low-noise current amplifier; Current measurement; Noise; Operational amplifiers; Resistors; SQUIDs; Temperature measurement; Uncertainty; Ammeters; calibration; current measurement; measurement uncertainty; precision measurements;
Conference_Titel :
Precision Electromagnetic Measurements (CPEM 2014), 2014 Conference on
Conference_Location :
Rio de Janeiro
Print_ISBN :
978-1-4799-5205-2
DOI :
10.1109/CPEM.2014.6898556
