ADC Input Currents Measurement

Jakub Svatos, Jan Fischer, Jan Holub

Abstract

The contribution introduces the possible issue of internal CMOS Successive Approximation Register microcontroller's Analog-to-Digital Converters input currents. If the microcontroller also contains a multiplexer, it can lead to consequences caused by the sample-and-hold block that is part of a charge redistribution Analog-to-Digital Converter. The article presents its nature, the possibility of its measurement, and a simplified model of such an MCU analog inputs behavior. The simplified model and derived formulas can help the unacquainted user in a data acquisition system with the MCU design when measuring signal sources with non-negligible internal resistance. The introduced parameters, which cannot be found in datasheets, can be essential for users.

Keywords

ADC, Current, Measurement

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IMEKO-TC4-2023-07.pdf

DOI

10.21014/tc4-2023.07

IMEKO TC

TC4 - Measurement of Electrical Quantities

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