The THRX_COUNT bits in the ALERT_CONFIG register offer robust noise filtering and immunity against false tripping while the TMAG5170D-Q1 implements the ALERT function for a specific magnetic or temperature threshold crossing. With THRX_COUNT at default 00b, only one measured value must cross the threshold to be considered a valid threshold crossing event. With THRX_COUNT at 11b, four successive measured values must cross the threshold to be considered a valid threshold crossing. An internal counter tracks and records the number of threshold crossing for a given sensor.

The counter resets if any of the below events occur:

• The device meets the threshold cross count for the specified number per the THRX_COUNT bits, the corresponding *CH_THX bit(s) are set, and the SPI read of the SYS_STATUS register occurred
• If a measured result does not cross the threshold

When the ALERT pin is configured to work as a magnetic switch, the threshold count is active for both low-to-high and high-to-low transitions, offering noise immunity in both directions of the threshold cross.