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© 2022 ROHM Co., Ltd.
No. 64UG118E Rev.002
Feb.2022
User’s Guide
Figure 40. Plotter view with FFT functionality (logarithmic and dB scale)
1.4.1.5
Advanced Data Path (ADP)
Advanced Data Path (ADP) is a special ASIC level functionality available only for the KX132-1211 / KX134-1211 accelerometers, which consists
of three blocks including a configurable second order low-pass filter, first order low-pass or high-pass filter, and an RMS calculation engine. The
user can configure each stage of the ADP individually or they can be bypassed with the corresponding register settings using the register editor.
The output of the ADP engine can be monitored with the Plotter by viewing the Advanced Data Path channel.
To review the ADP functionality further, consider the example FFT signal shown in (Figure 39) and FFT signal from ADP output shown in (Figure
41). In these examples, the selected stream for the KX132-1211 sensor is ADP data & WUF/BTS Detection 1600Hz Band pass 200Hz-400Hz
with RMS. The Advanced Data Path is configured to band-pass filter topology with the signal bandwidth set from 200Hz to 400Hz. From (Figure
41) it can be seen that the band pass filtered signal produces a 10dB attenuation at 600Hz. The output is then routed to the RMS engine and then
to the Wake-Up/Back-to-Sleep engines. The wake-up threshold is set to 48 counts, and the Wake-up counter is set to 5 counts. When raw data
) is disabled the selected data stream will scale ADP output directly to the values (unit is WUF/BTS Threshold). The Reference
line is also moved to the wake-up threshold level (48) for easier comparison of the threshold value and the ADP output value
) Also, the Wake-up pop-up window is enabled (
). The pop-up window will appear when a wake-up event is
active, e.g., when a signal within band-pass frequency range is present (
).
