Low Noise Charge Sensitive Amplifiers

Low Noise Charge Sensitive Amplifiers for Cosmic Dust

4.6 billion years ago, our solar system was born out of an interstellar dust- and gas cloud. Therefore by analyzing interstellar and other cosmic dust particles we can develop a better understanding of the conditions during the development of our solar system.

Principle schematic with detector and amplifier
Principle schematic with detector and amplifier

A common way to determine the origin of cosmic dust particles is to evaluate charges induced in an electrode-array during the fly-by of the particle. This technique utilizes the natural charge-up of particles trough solar UV-radiation in space. Unfortunately the charge of the particles is in the range of only a couple to a few thousand electros. Therefore extremely sensitive detectors and amplifiers are needed.

Charge Sensitive Amplifier on PCB
Charge Sensitive Amplifier on PCB

In a joint effort with IRS/University of Stuttgart, INT researches different methods to improve both the noise level and the bandwidth of the detection systems. One approach thereby focusses on the development of a better understanding of the interactions of the separate system components by creating a system-wide model, containing all subcomponents.

The work on INT focuses on minimizing the noise occurring in these amplifiers while maintaining a bandwidth of 7 Hz to 300 kHz or 10 kHz to 10 MHz. The goal is to be able to detect particles whose charge is in the range of only about 100 elementary charges.

Charge Sensitive Amplifier IC
Charge Sensitive Amplifier IC

In terms of circuit design the efforts focus both on researching noise reduction techniques for charge amplifiers and on increasing the bandwidth both to lower and higher frequencies by employing new circuit topologies. Significant improvements can often already be reached by utilizing the optimum process technology for a given frequency range.

Publications

  1. 2019

    1. S. Kelz, M. Grözing, and M. Berroth, “Dielectric-Loss Induced Noise in High Impedance Circuits,” in Workshop Analogschaltungen, presented at 21. Workshop Analogschaltungen, Stuttgart, Germany, 2019.
  2. 2018

    1. S. Kelz, T. Veigel, M. Grözing, and M. Berroth, “A Fully Differential Charge-Sensitive Amplifier for Dust-Particle Detectors,” in Conference on Ph.D. Research in Microelectronics and Electronics (PRIME), Prague, Czech Republic, 2018, pp. 13--16.
    2. S. Kelz, “A Fully Differential Charge-Sensitive Amplifier for Dust-Particle Detectors,” in Workshop Analogschaltungen, presented at 20. Workshop Analogschaltungen, Freiburg, Germany, 2018.

Contact

M.Sc.

Sebastian Kelz

Research staff member

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