I have a question regarding the self test results. We are getting higher population of the results than appear in the datasheet. Axis Y has significant deviation from the typical value on many devices.
Following ADXL362 rev.D (Table 1), self test typical change is around 550 for X and Z and -550. Fig 20-22 shows quite tight population of the output delta value than what we’ve got in production.
Our Self Test Configuration:
- TA = 25°C, VS = 1.8V, VDD I/O = 1.8V, 25Hz ODR, HALF_BW = 0, ±2g range, acceleration = 0 g
- 300ms delay after asserting self test by setting the ST bit in the SELF_TEST register, Address 0x2E.
Tried to evaluate the difference between 1.8V to 2.0V and found that the main difference is in axis Y (about 156 difference in the delta). X and Z have about 50.
Some examples of output delta results I'm getting:
X=672 Y=-228 Z=549
X=720 Y=-380 Z=585
X=861 Y=-61 Z=675
If I’m compensating the difference from the threshold in Table 1 our devices can pass the self test but still Y axis has higher deviation from the typical value.
Your comments are appreciated. We also would like to know if we are missing anything in our consideration.