In out production process, the self-test function of LSM303D was taken to perform product testing. The Self-test was always OK when VDD was about 2.7V. However, we found that when the VDD was set to 3.3V, some LSM303Ds could not pass the self-test. It seemed than some times no differences could be observed with the self-test bit (AST) set to '0' and '1' when VDD set to 3.3V.
Is there anything wrong?