Hi,
We have designed the TMS320C6678 board by using of UCD9244 with UCD7242 for deriving 8 voltage outputs. The board has been fabricated and tested without any issue. Also we are using the board for development purpose for more than 3 months without any issue. All of sudden , one UCD7242 which produces 3.3V & 1.8V is not working. We just re-programmed and changed the new IC . It didn't help. We have supplied external 1.8V & 3.3V from outside power supply to rule out board components issue on 1.8V & 3.3V voltage rail. The board is working under this condition.
The other UCD7242 with UCD9244 which produces 1.2V & 3.3V is working without any issue till now.
Also one more board with proper heat sink mounted which went for 55'C high temperature test . The same power driver which produces 3.3V & 1.8V is not working .We have supplied external 1.8V & 3.3V from outside power supply to rule out board components issue on 1.8V & 3.3V voltage rail. The board is working under this condition.
I have attached the Fusion GUI Screen shots for all power rails with this post.
Please suggest me what can be the cause.
Regards,
Sakthi.AUCD9244.docx