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

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 ± 10 mA and ± 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 highperformance OPMs. They exhibit low noise of 146.3 pA/ √ Hz and 4114 pA/ √ Hz which translates to 14.57 ppb/ √ Hz and 16.46 ppb/ √ Hz noise relative to full scale.