Implementation of a Fully Differential Low Noise Current Source for Fluxgate Sensors

Maximilian Scherzer, Mario Auer, Aris Valavanoglou, Werner Magnes

Research output: Chapter in Book/Report/Conference proceedingConference paperpeer-review


In this paper the implementation of a fully differ-ential low-noise current source is presented. It was designed to be used in the feedback path of a fluxgate magnetometer, however, the concept is applicable wherever a low noise and precise current is required. The current source is driven by a transimpedance amplifier that buffers the output of a current-steering DAC. To meet the mandatory precision as well as the required noise level a detailed analysis of the proposed circuit was carried out. The complete feedback path is integrated on chip using a 180 nm CMOS technology and occupies a total area of 2 mm2. The proposed design results in a signal-to-noise ratio of more than 104 dB for a bandwidth of 512 Hz, requiring only a supply voltage of 3.3 V. Moreover the current source is capable of driving currents of more than 18 mA into fluxgate sensors with an inductance of up to 9 mH while consuming 70 mW of power. To the best of the authors' knowledge the designed current source offers the best performance in terms of noise for fluxgate sensor front ends.
Original languageEnglish
Title of host publication2022 IEEE 13th Latin America Symposium on Circuits and System (LASCAS)
ISBN (Electronic)978-1-6654-2008-2
Publication statusPublished - 4 Mar 2022
Event13th Latin American Symposium on Circuits and Systems: LASCAS 2022 - Santiago, Chile
Duration: 1 Mar 20224 Mar 2022


Conference13th Latin American Symposium on Circuits and Systems
Abbreviated titleLASCAS 2022
Internet address


  • Current Source
  • Fluxgate Sensor
  • Fully Differential
  • Low Noise
  • Space Applications

ASJC Scopus subject areas

  • Safety, Risk, Reliability and Quality
  • Electrical and Electronic Engineering
  • Hardware and Architecture


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