Related Experiment Video
Updated: Aug 12, 2025

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
Published on: June 3, 2015
Ultra-low noise, bi-polar, programmable current sources
M S Mrozowski1, I C Chalmers1, S J Ingleby1
1Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG, United Kingdom.
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 and ±250 mA on three independent channels with 16-bit resolution. Both devices feature a narrow 1/f noise bandwidth of 1 Hz, enabling magnetic field manipulation for high-performance OPMs. They exhibit a low noise of 146 pA/Hz and 4.1 nA/Hz, which translates to 15 and 16 ppb/Hz noise relative to full scale.
Related Concept Videos
Bipolar Junction Transistor
MOSFET Amplifiers
Multiple Voltage Sources
In series, the positive terminal of one battery is connected to the negative terminal of another battery. Hence, the voltage of each battery is added to give the net voltage, which is increased because each battery boosts the electrons that enter it. The same current flows through each battery because they are connected in series.
Batteries are...
Biasing of FET
In an N-channel JFET, the structure consists of N-type material forming the channel on a P-type substrate, with the...
Biasing of P-N Junction
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
Controlled-Current Coulometry: Overview

