[79] NFCT: A false EVENTS_FIELDDETECTED event occurs after the field is lost

This anomaly applies to IC Rev. Engineering C, build codes QFAA-BB0, CHAA-BA0, CIAA-BA0.

It was inherited from the previous IC revision Engineering B.

Symptoms

A false EVENTS_FIELDDETECTED event occurs.

Conditions

The task TASK_SENSE is triggered within 270 µs of the event EVENTS_FIELDLOST.

Consequences

EVENTS_FIELDDETECTED will occur after a field is lost. (SHORT between eventfieldlost and taskSense should not be used since a false fieldDetected event will occur from using the task.)

Workaround

  • Wait 170 µs after an EVENTS_FIELDLOST event before triggering TASK_SENSE for temperatures ≥ 0°C.
  • Wait 270 µs after an EVENTS_FIELDLOST event before triggering TASK_SENSE for temperatures < 0°C.
Important: This anomaly was changed compared to the original publication.