Other Parts Discussed in Thread: DRV8818
In one of our products we use DRV8811 chips to control stepper motors. We faced some issue with these chips in the past, where the driver "locked up" and motor movement ceased to work properly. It looked like the driver was not able to perform steps anymore. A power reset was required to get out of this state. Some time after the erroneous behaviour was discovered, we received the information from TI, that the issue was caused by a silicon bug. We replaced the chips with newer silicion revision (date code newer than 98TC -> production after 08/2009) and there has never been any problem in the meantime. All of our devices undergo long-term testing (3 days at minimum) before shipment.
Just recently, after several days of runtime during long-term testing, some of our devices showed the erroneous behaviour again. The marking on the chips is 54TC DLQ8 respectively 52TC AHK5. Is the production year 2015 or 2005 ?
If it is 2015, was anything changed inside the chip that might explain the re-apperance of the issue ?
Devices failed in customer applications already and we need to ship new products in the next days. Therefore timing is very critical, and we need clarification on this issue as fast as possible.