Low noise constant current source for bias dependent noise measurements

TL;DR

This paper presents a low noise, adjustable constant current source and a specialized voltage preamplifier for precise bias-dependent noise measurements in disordered systems, covering a wide current range with minimal noise contribution.

Contribution

It introduces a versatile low noise constant current source and a modified voltage preamplifier tailored for bias-dependent noise measurements, enhancing measurement accuracy.

Findings

The current source operates from 1 μA to tens of mA with low noise.

The source provides a high voltage compliance of around 20 V.

The modified preamplifier effectively reduces noise in measurements.

Abstract

A low noise constant current source used for measuring the $1/f$ noise in disordered systems in ohmic as well as non-ohmic regime is described. The source can supply low noise constant current starting from as low as 1 $\mu$A to a few tens of mA with a high voltage compliance limit of around 20 Volts. The constant current source has several stages which can work in a standalone manner or together to supply the desired value of load current. The noise contributed by the current source is very low in the entire current range. The fabrication of a low noise voltage preamplifier modified for bias dependent noise measurements and based on the existing design available in the MAT04 data sheet is also described.