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

Area of Science:

• Instrumentation and Measurement
• Applied Physics
• Electronics Engineering

Background:

• Optically Pumped Magnetometers (OPMs) require highly stable and low-noise current sources for optimal performance.
• Existing current source solutions may lack the necessary precision, programmability, or open-source accessibility for advanced research.

Purpose of the Study:

• To design and implement fully open-source, ultra-low noise programmable current source systems.
• To create versatile current drivers suitable for OPMs and other sensitive applications.
• To achieve high-resolution, bi-directional current control with minimal noise.

Main Methods:

• Development of two distinct configurations of programmable current source systems.
• Implementation of 16-bit resolution for precise current control.
• Characterization of noise performance, including 1/f noise bandwidth and amplitude.

Main Results:

• The systems provide bi-directional current ranges of ±10 mA and ±250 mA across three independent channels.
• Achieved a narrow 1/f noise bandwidth of 1 Hz, crucial for magnetic field manipulation.
• Demonstrated ultra-low noise levels of 146 pA/√Hz and 4.1 nA/√Hz, translating to 15 and 16 ppb/Hz relative to full scale.

Conclusions:

• The developed open-source current sources meet the stringent requirements for high-performance OPMs.
• The systems' specifications indicate broad applicability in various scientific fields needing precise current control.
• The open-source nature facilitates accessibility and further development within the research community.