ZSSC5101
Evaluation Kit Description
Kit Description
April 17, 2015
© 2015 Zentrum Mikroelektronik Dresden AG
— Rev. 1.00
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the
prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
14 of 25
4.3.1.
Offset Calibration
AMR sensors typically exhibit a temperature dependent offset. An offset calibration can greatly improve the
accuracy of the sensor system by eliminating these errors. In addition, the offset calibration procedure also
improves non-linearity caused by a misaligned (non-centered) magnet.
To start an offset calibration, ensure that a magnet is placed over the s
ensor and click the “START
CALIBRATION
” button, which is shown in Figure 4.3. The button label changes to “Calibrate Offset.”
Rotate the magnet slowly until the values for SIN Min/Max and COS Min/Max that are displayed
in the module’s
section stop changing (see Figure 4.4). Verify that the Min/Max values are in a range of approxi/- 11000
or wider. Then click the
“CALIBRATE OFFSET” button.
Figure 4.4 Example Graph and Max/Min Values for Module 1
The software calculates the offset parameters and stores them in place of the default factory settings in the
ZSSC5101’s EEPROM. The ZSSC5101 is now calibrated for the offset of the AMR position sensor at room
temperature. The same procedure can be repeated under high temperature conditions
by selecting the “High
temperature” checkbox. This ensures accurate output values in a range between room temperature and the high
temperature; e.g., the temperature that is applied to the ZSSC5101 during high temperature calibration: 150°C.
After the programming is finished, the button label changes back to
“START CALIBRATION.”
Note that an offset calibration can be repeated several times. Each new setting will overwrite the old setting in the
EEPROM. A misalignment of the magnet also leads to an offset error. Therefore, for best performance, it is
recommended that an offset calibration be repeated if the magnet is changed for any new assembly of the sensor
and the magnet.
