Ultra‐stable, low‐noise two‐stage current source concept for electronics and laser applications

This study presents a two‐stage current source concept which features low‐current noise, excellent drift and stability for higher operating currents. Generally, it is much easier to obtain higher stability and lower‐noise parameters for small operating currents rather than large ones. This fact was...

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Bibliographic Details
Main Author: Grzegorz Dudzik
Format: Article
Language:English
Published: Hindawi-IET 2017-11-01
Series:IET Circuits, Devices and Systems
Subjects:
Online Access:https://doi.org/10.1049/iet-cds.2016.0489
Description
Summary:This study presents a two‐stage current source concept which features low‐current noise, excellent drift and stability for higher operating currents. Generally, it is much easier to obtain higher stability and lower‐noise parameters for small operating currents rather than large ones. This fact was used within this concept, where a precise low‐current source (the second stage) corrects the fluctuations of high‐current one (the first stage). In details the theory of operation for setup, the noise‐sources analysis and measurement results are presented. For a maximum operating current equals 1 A, the current noise density of 126 nA/√Hz (at f = 1 kHz), long‐term stability of ±2.1 ppm and temperature coefficient equal 2.8 ppm/°C, were obtained, whereas the current noise below 1 nA/√Hz was obtained for lower operating currents. Presented circuit is inexpensive to construct, non‐thermally stabilised and very small size (1 × 1.2 in2). The obtained parameters are competitive to commercial current drivers designed for laser applications. The two‐stage current source has been successfully implemented in a fully integrated diode‐pumped solid‐state lasers.
ISSN:1751-858X
1751-8598