Good evening,
We have been developing an application using the IAM-20680HT and HP devices for ~18 months, but have started to notice recently issues matching the acceleration values from the IAM devices, to other accelerometers used in our product.
We think the issue may be related to filter attenuation. The datasheet does not specific if the low pass filter is a 2, or 4 pole filter - and thus wether the roll off rate is 20dB/decade, or 40dB/decade - please may you confirm?
Hello.
Thanks for your inquiry and your interest in our products.
Roll-off rate of IAM-20680HT low pass filter is 20dB/decade.
Hope it helps.
Best regards,
Simone
Hi Simone,
Thank you for your feedback. I had not noticed this post had been replied to actually - so, sorry for my late reply.
Are you able to supply some further information here, as the IAM-20680 having only a first order (20dB/decade) filter does not match our test data. The filter appears to behave much more closely to that of a 2nd order (40dB/decade) filter.
However, the sensor does appear to pick up aliased components of high frequency noise worse than other sensors with 4th order filters in, as such - the evidence seems to suggest that the IAM-20680 does indeed have a 1st order filter, but a rapidly reduced frequency response of the sensor itself.
Are you able to supply any frequency response information for the sensor itself, excluding filter?
Many thanks
Hello Simone,
I am revisiting this again now, are you able to provide any input please, as this post is nearly 8 months old. We have gained far more experience with this sensor over this time, and all the data we have suggests the filter is indeed a 40dB/decade filter, not a 20dB/decade filter.
Regards