Forum Discussion

K_Crocker's avatar
K_Crocker
Icon for Occasional Contributor rankOccasional Contributor
6 months ago
Solved

JTAG failure

I have several PCBAs that have been returned from the customer with failed 10CX150YF780E6G FPGAs. They exhibit the symptom of the TDI being connected to TDO with a short (~5.2ns) delay, eg. much less...
Configuration
  • FakhrulA_altera's avatar
    FakhrulA_altera
    6 months ago

    Hi,


    Based on the shared information, the 10CX150YF780E6G FPGAs is most likely caused by ESD (electrostatic discharge) damage on the JTAG pins. This matches the symptom where TDI is directly echoed to TDO with a short delay.


    To avoid this problem in future, we recommend to add ESD protection (such as TVS diodes and series resistors) on the JTAG lines, and to ensure proper ESD handling procedures when connecting the programming cable.


    If you have any questions or need further assistance, please let me know.


    Thank you.


    Fakhrul


FakhrulA_altera's avatar
FakhrulA_altera
Icon for Regular Contributor rankRegular Contributor
6 months ago

Hi,


Based on the shared information, the 10CX150YF780E6G FPGAs is most likely caused by ESD (electrostatic discharge) damage on the JTAG pins. This matches the symptom where TDI is directly echoed to TDO with a short delay.


To avoid this problem in future, we recommend to add ESD protection (such as TVS diodes and series resistors) on the JTAG lines, and to ensure proper ESD handling procedures when connecting the programming cable.


If you have any questions or need further assistance, please let me know.


Thank you.


Fakhrul


K_Crocker's avatar
K_Crocker
Icon for Occasional Contributor rankOccasional Contributor
6 months ago

Thanks, Fakhrul!! I've already added TVS devices and am strongly considering adding 20 Ohm series resistors.