Hello All,
I decided to do a project based on ATtiny406 and last month I ordered 5 prototypes. The ATtiny406 on the first prototype lasted just for about one week, after which it would no longer would program with error: "Framing Error", so I dismissed it as a fluke.
However, after one month the ATTiny406 on the second prototype also stopped programming with error "PDI physical timed out. (25)", of course changing to high voltage UPDI doesn't do anything. Although the microcontroller seems to function normally (UART and Timers are working but it just won't program).
So now I am puzzled I don't know what could be killing these ATTinys.
Also, it's worth mentioning that System VCC is 5.4V, although I don't know why this should be a problem.
Kind Regards,
Sparsh
Update: Three Chips are now dead
Update: more information: The first chip died within a week of testing as I am developing the firmware, the code is uploaded to chip several times, the first chip died with "framing error" and showed impedance of 13k ohm on the programming pin, the second chip lasted for over a month, I might have programmed it like 20 to 30 times at least until finally yesterday I could no longer program it all of a sudden and it gave the error "PDI physical timed out. (25)" but the impedance on the programming pin is normal about 47k ohms, the third chip died today it only lasted less than 24 hours, and I get the same error on this one “framing error” as with the first one, only again the impedance of the programming pin is low about 13k ohms,
Also, it's worth mentioning that at the time second one died I was continuously connecting and disconnecting the programmer as well connecting and disconnecting the power to the board.
Update: Almost Full schematic
ibb.co/09BQ8Vz
Update: Full schematic attached in PDF format