A Low-Noise and Quasi-Ideal DC Current Source Dedicated to Four-Probe Low-Frequency Noise Measurements

Abstract

In this paper, a dc current source dedicated to fourprobe low-frequency noise measurements is presented. An output impedance value of 3 MQ with a maximum output current of 1.5 mA was achieved. The white noise level of the current source was measured to be 4 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-23</sup> A <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> · Hz-1 with a corner frequency of 30 Hz. Thanks to its quasi-ideal behavior in terms of noise level and high output impedance value, this current source can be used to measure the intrinsic noise of materials using four-point measurements without any experimental or analytical corrections.