JAJSJ71A June 2020 – December 2021 TMAG5170-Q1
PRODUCTION DATA
The TMAG5170-Q1 offers independent configurations to perform linear position measurements in X, Y, and Z axes. To calculate the expected error during linear measurement, the contributions from each of the individual error sources must be understood. The relevant error sources include sensitivity error, offset, noise, cross axis sensitivity, hysteresis, nonlinearity, drift across temperature, drift across life time, and so forth. For a 3-axis Hall solution like the TMAG5170-Q1, the cross-axis sensitivity and hysteresis error sources are insignificant. Use Equation 15 to estimate the linear measurement error calculation at room temperature.
where
In many applications, system level calibration at room temperature can nullify the offset and sensitivity errors at 25°C. The noise errors can be reduced by further digital averaging the sensor data in a microcontroller. Use Equation 15 to estimate the linear measurement error across temperature after calibration at room temperature.
where
If room temperature calibration is not performed, sensitivity and offset errors at room temperature must also account for total error calculation across temperature (see Equation 17).
where
The table below summarizes linear measurement error estimate for z-axis with magnetic field range of ±50mT and CONV_AVG =101b:
Input Field 50mT | Input Field 25mT | |
---|---|---|
Error % for z sensor at 25°C without any calibration | 2.6% | 2.8% |
Error % for z sensor across temperature after 25°C calibration | 3.0% | 3.6% |
Error % for z sensor across temperature without 25°C calibration | 4.0% | 4.5% |