I am detecting the shock which applied to my products. I use ADXL354 and configured as 2g. But I forgot connected those capacitors which showed in figure 59 in its datasheet. There is a 500mV 210Khz (don't remember the exactly number) saw wave at pin 10. So Xout, Yout and Zout also have noise based that frequency. After adding those two capacitors, 0.1uF and 1.0uF, the noise is drop down to 5mV, it is still not good but acceptable. Is there something wrong? is the noise at pin10 expected?
The second question is once the board went to high temperature environment, the noise at output (Xout, Yout and Zout) start increasing as temperature. We have to qualified it to 175C. Is something wrong?