A spinning current circuit for nanotesla range resolution in Hall measurements
| Autor: | Vincent Mosser, Nicolas Matringe |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Physics
business.industry 010401 analytical chemistry Electrical engineering Differential amplifier 02 engineering and technology Breadboard 021001 nanoscience & nanotechnology 01 natural sciences Transfer function Noise (electronics) 0104 chemical sciences law.invention law Hall effect sensor Resistor 0210 nano-technology business Telecommunications Electrical impedance Frequency modulation |
| Zdroj: | SAS |
| Popis: | Thanks to the very linear behavior of Quantum Well Hall Sensors (QWHS), the Spinning Current Modulation Technique (SCMT) is in principle able to suppress all the offset and low-frequency noise contributions from the Hall sensing element, its electronics and interconnects. This requires first a right choice of the modulation sequence, but also a good balance of all the elements involved in the analog circuitry, including the analog switches, differential amplifiers, filters, interconnects, etc. as a function of the sensor impedance. We developed a breadboard aimed at optimizing the operating conditions for a broad spectrum of sensor types and applications, using pluggable modules for adapting the gain and transfer function. The modulation sequence, modulation frequency, and fine-tuning of the delays involved in the spinning sequence are driven by a microcontroller. With the present circuit, we were able to optimize the biasing, filtering and spinning current modulation conditions for various Hall sensing devices types, achieving an offset reduction by at least 4 decades and a residual white noise close to the Johnson-Nyquist thermal noise. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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