Abstract
This paper presents a theoretical analysis and measurements of the current noise of several chopper instrumentation amplifiers, which demonstrate that the charge injection and clock feed-through associated with the MOSFETs of the input chopper give rise to significant input current and current noise. In combi-
nation with high source impedances, this “chopper noise” is converted to voltage noise, which may then be a significant contributor to the amplifier’s total input-referred voltage noise. Chopper noise has a white power spectral density, whose magnitude is roughly proportional to the chopping frequency. Design guidelines are proposed to reduce chopper noise, as well as the use of a clock-boot-
strapped chopper, which generates significantly less noise than a traditional chopper.
nation with high source impedances, this “chopper noise” is converted to voltage noise, which may then be a significant contributor to the amplifier’s total input-referred voltage noise. Chopper noise has a white power spectral density, whose magnitude is roughly proportional to the chopping frequency. Design guidelines are proposed to reduce chopper noise, as well as the use of a clock-boot-
strapped chopper, which generates significantly less noise than a traditional chopper.
Original language | English |
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Pages (from-to) | 1575-1584 |
Number of pages | 10 |
Journal | IEEE Journal of Solid State Circuits |
Volume | 48 |
Issue number | 7 |
DOIs | |
Publication status | Published - 2013 |
Bibliographical note
Accepted Author ManuscriptKeywords
- Charge injection
- chopper amplifier
- chopping
- current noise
- high-impedance sensors
- $1/f^{2}$noise