= RTD Ratiometric Measurements and Filtering Using the ADS1148 and ADS1248 Family of Devices by Luis Chioye
{c}
{tag=Work by Luis Chioye}
https://www.ti.com/lit/an/sbaa201/sbaa201.pdf
The first-page abstract and the discussion of low-pass filter design explain why signal and reference filters must have matching responses to retain excitation-noise cancellation.
Additional cited passages: §§3.1–3.2, printed pp. 6–9, Figures 3-1–3-4, resistance-decade-box noise tests comparing reference-only filtering with matched signal/reference filters. The mismatched-filter experiment uses 1 mA excitation, a 2 kΩ reference, gain eight and 20 samples per second. https://www.ti.com/lit/an/sbaa201/sbaa201.pdf[Printed pp. 6–9, apparatus and noise-versus-input observations]{ref}
Additional cited passage: §3.4, printed p. 11, and Table 3-1, electrical settling after excitation activation and before acquisition; the table expresses resolution-dependent settling requirements in RC time constants. https://www.ti.com/lit/an/sbaa201/sbaa201.pdf[Printed p. 11, initial filter settling and timing considerations]{ref}
Back to article page
