LEAD COMPENSATION IN A PWM SENSOR INTERFACE

A. Custodio, R. Pallàs-Areny, R. Bragós

Abstract

Error analysis of a resistive sensor-to-microcontroller interface based on pulse width modulation (PWM) and time ratio measurement (sensor resistance over reference resistor), shows that leads resistance produce zero, gain, and nonlinearity errors. Because at the calibration points these errors are nulled out, several calibration resistors selected according to the sensor resistance range would reduce those errors in the full range. Two-point calibration and time ratio measurement yield errors smaller than 1 W for lead resistance of 10.5 W and sensor resistance from about 600 W to 3550 W, which is the typical variation range for a PT1000 temperature sensor.

Keywords

sensor interface, lead resistance compensation

Download

IMEKO-WC-2000-TC4-P119.pdf

DOI

-

IMEKO TC

TC4 - Measurement of Electrical Quantities

Back to the proceedings