Part Number: TMS320F280049
Hi Champ,
I am asking for my customer.
They are using 100-pin(PZ) F280049 for the new design. Consider it will migrate to F280039 in future, they would reserve the part suggested in the migration guide.
In Table 2-2 and Figure 2-2, it provides the dual routing technique for medium incompatibility.
The pin number 14 which is PGA1_GND in F280049, while it is ADC A6 in F280039.
As dual routing technique illustrated, the PGA1_GND is DNP in F280049, while it is connected with 0Ohm used as an ADC pin in F280039.
The problem is the customer isn't going to use PGA, so the PGA_GND is seen as an unused pin which it should tie to VSSA referred to the datasheet in section 6.6 Connections for Unused Pins.
SO, there is a conflict deign (PGA_GND ties to VSSA) after changing the device from F280049 to F280039 since the pin 14 is connected to analog ground and signal source through 0 Ohm.
Is the only solution for adding a switch to switch over between VSSA and open circuit ? Would there be a better solution to solve that ?
Thanks and regards,
Johnny
