AN12004, Sensors data change detection (SDCD) block overview with examples for FXLS896xAF and FXLS897xCF accelerometers - Application note

This application note introduces the Sensor Data Change Detection (SDCD) block integrated into the FXLS896xAF and FXLS897xCF 3‑axis accelerometer families. It summarizes how the device identifies inertial events—such as motion, no‑motion, tap, freefall, and transient activity—using configurable thresholds, debounce timers, interrupt logic, and reference update modes. The document also outlines practical use‑case patterns to guide developers in applying SDCD functionality within motion‑sensitive designs.

What's Inside

• SDCD functional overview: High-level explanation of event detection capabilities, threshold comparisons, and SDCD operating behavior.
• Programmable thresholds: Description of upper/lower threshold settings and their relationship to full-scale range and sensitivity.
• Debounce mechanisms: Summary of OT/WT debounce counter operation and how timing stability affects event recognition.
• Interrupt logic: Overview of axis selection, polarity, latching behavior, and routing options for motion‑related interrupts.
• Reference update modes: Explanation of absolute and relative modes, including how reference values update during evaluation.
• Example use cases: Concept‑level descriptions of shake, no‑motion, twist, freefall, and transient/tap scenarios without gated details.