Title :
Ultra low-noise current sources
Author :
Ciofi, Carmine ; Giannetti, Romano ; Dattilo, Vincenzino ; Neri, Bruno
Author_Institution :
Dipt. di Ingegneria dell´´Inf. Elettronica, Inf Telecomunicazioni, Pisa Univ., Italy
fDate :
2/1/1998 12:00:00 AM
Abstract :
The solid state DC current sources available on the market are not suitable for applications in low noise measurement systems because of the high level of low-frequency noise introduced in the measurement chain. The most important cause of low-frequency noise in such instruments is the solid state device used as a voltage reference (usually a Zener diode). This problem has been solved, in the instrument described in this paper, by using a new circuit topology in which the solid-state voltage reference has been substituted by a low-noise battery. The instrument, capable of supplying a current as high as 100 mA, is characterized by a low-frequency noise level some orders of magnitude lower than that of similar commercial instrumentation
Keywords :
circuit noise; constant current sources; electric noise measurement; 100 mA; circuit topology; current supplies; low noise FET; low noise measurement systems; low-frequency noise level; low-noise battery; solid-state voltage reference; ultralow-noise current sources; Batteries; Circuit topology; Current measurement; Current supplies; Diodes; Instruments; Low-frequency noise; Noise measurement; Solid state circuits; Voltage;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
