Ultra-low noise, bi-polar, programmable current sources

TL;DR

This paper introduces open-source, ultra-low noise, programmable current sources with bi-polar capabilities, designed initially for magnetometry but adaptable for various applications, demonstrating high precision and low noise performance.

Contribution

The paper presents novel open-source designs for ultra-low noise, bi-polar programmable current sources with high resolution and low noise, suitable for sensitive magnetic field applications.

Findings

Achieved noise levels of 146.3 pA/√Hz and 4114 pA/√Hz.

Supported bi-directional current ranges of ±10 mA and ±250 mA.

Narrow 1 Hz 1/f noise bandwidth enables high-performance magnetic manipulation.

Abstract

We present the design process and implementation of fully open-source, ultra-low noise programmable current source systems in two configurations. Although originally designed as coil drivers for Optically Pumped Magnetometers (OPMs), the device specifications make them potentially useful in a range of applications. The devices feature a bi-directional current range of $\pm$~10~mA and $\pm$~250~mA respectively on three independent channels with 16-bit resolution. Both devices feature narrow 1/f noise bandwidth of 1~Hz, enabling magnetic field manipulation for high-performance OPMs. They exhibit low noise of 146.3~pA/$\sqrt{\mathrm{Hz}}$ and 4114~pA/$\sqrt{\mathrm{Hz}}$ which translates to 14.57~ppb/$\sqrt{\mathrm{Hz}}$ and 16.46~ppb/$\sqrt{\mathrm{Hz}}$ noise relative to full scale.