Other Parts Discussed in Thread: TPS62000,
Hello,
I am using twoTPS62000 to power a SM470R1B1 with 1.8V and 3.3V.
At 187C the 3.3V starts fluctuating between 2.9V and 3.0V - this is critical because it resets the microcontroller.
When cooling it down, it recovers at 175C.
The TPS62000 used for the 1.8V output, works well at 190C, just a small increase in voltage to 1.89V.
The two circuits are almost identical, the difference is the feedback resistors and the inductor 10uH for 1.8V and 22uH for the 3.3V. I tried with 10uH on the 3.3V and got the same result.
Now, my best guess is that one part (FLASH memory, EEPROM memory) that is powered by the 3.3V, increases its power consumption and make the voltage to drop.
It is difficult to measure the circuit - it is in an oven and at 190C. To measure the DC/DC converters outputs, I am using external wires soldered on the PCB.
What can create this problem?
Thanks,
Marius Raducanu